Carrie Vance - Academia.edu (original) (raw)
Papers by Carrie Vance
Journal of Animal Science
Artificial insemination (AI) with fresh semen is the primary breeding tool in the swine industry.... more Artificial insemination (AI) with fresh semen is the primary breeding tool in the swine industry. However, the heterogenous semen doses create challenges in boar studs due to the lack of consistent assessment criteria. Seminal plasma (SP) surrounding spermatozoa is a great source of reliable non-invasive biomarkers of sperm quality. It contains a wide array of bioactive molecules, whose dynamic compositions in response to extrinsic and intrinsic factors influence sperm motility and morphology. Therefore, we hypothesize that the miRNA content of extracellular vesicles (EVs) found in SP may reflect semen quality. Our study aimed to characterize poor vs. good quality semen and compare miRNA profiles of SP-derived EVs. Raw semen was collected (n = 75) from sexually mature Duroc boars at a commercial stud (Prestage Farms, MS) for 8 weeks. Semen samples were subjected to sperm motility and morphology analyses and subsequently classified as poor (n = 38) or good (n = 37) quality based on a...
Reproduction, Fertility and Development, 2017
The capability of near-infrared spectroscopy (NIR) to detect biomolecules in aqueous solutions, a... more The capability of near-infrared spectroscopy (NIR) to detect biomolecules in aqueous solutions, a sub-field of NIR called aquaphotomics, has yet to be fully explored. Aquaphotomics references water absorbance patterns and wavelength shifts in the 1st overtone of the water spectrum as they change patterns with solute composition and concentrations. Recently, NIR was used as a rapid method for detecting oestrus in Holstein raw milk and for monitoring reproductive stages in urine of the Bornean Orangutan (Pongo pygmaeus) and the giant panda (Ailuropoda melanoleuca). Near-infrared spectroscopy detects bond vibrations from organic molecules and water to create unique absorbance patterns, which are used to profile complex mixtures of biomolecules. The objectives of this study are to (1) characterise serum NIR spectral profiles for oestrus, metestrus, and diestrus in mares, and (2) determine if NIR can accurately decipher these reproductive phases from serum due to the biochemical effects of reproductive hormones. Mare oestrus cycles were assessed every other day by ultrasound and serum hormone analysis. Serum was collected via jugular venipuncture on day 0, 2, 4, 8, and 16 of each cycle for 3 consecutive cycles from each mare. Radioimmunoassay analysis of reproductive hormones E2 and P4 was used to validate and characterise the NIR spectra. Spectra were collected from triplicate samples of 200 μL of serum in a 1-mm-path-length quartz cuvette with an ADS FieldSpec®3 spectrophotometer, at room temperature (22°C). Chemometric analysis (Unscrambler® X v.10.4; CAMO Software) included pretreatment with a Savitsky-Golay second-derivative function for visual inspection of spectral features and principal component analysis (PCA), after mean centering, for distinction of reproductive status. Spectral peaks at 1347, 1367, and 1465 nm were unique to serum collected from mares in oestrus exhibiting high E2 (11.87 to 16.88 pg mL−1). Early metestrus is characterised by prominent spectral peaks at 1383 and 1437 nm, corresponding to E2 levels (0.02 to 5.29 pg mL−1) and P4 levels (0.02 to 3.61 ng mL−1). Diestrus peaks were found at 1342, 1426, and 1473 nm, when P4 levels ranged from 5.14 to 9.60 ng mL−1. In our PCA models, 98% of the total variance in serum spectra between any pair of reproductive phases was described in only 3 spectral PCs, (PC1 = 83–86%, PC2 = 9–10%, PC3 = 2–5% of total variance). The PCA scores separated into distinct groups, indicating clear spectral profiles describing each reproductive phase uniquely. In conclusion, PCA analysis and spectral variances indicate that NIR, specifically aquaphotomics, has the theoretical capability to discriminate complex mixtures of biomolecules present in mare serum during oestrus, metestrus, and diestrus reproductive states. Study was supported by USDA-ARS Biophotonics Initiative grant #58-6402-3-018.
Journal of Inorganic Biochemistry, Jul 1, 2000
We are addressing the puzzling metal ion specificity of Fe-and Mn-containing superoxide dismutase... more We are addressing the puzzling metal ion specificity of Fe-and Mn-containing superoxide dismutases (SODs) [see C.K. Vance, A.-F. Miller, J. Am. Chem. Soc. 120(3) (1998) 461-467]. Here, we test the significance to activity and active site integrity of the Gln side chain at the center of the active site hydrogen bond network. We have generated a mutant of MnSOD with the active site Gln in the location 21 31 21 characteristic of Fe-specific SODs. The active site is similar to that of MnSOD when Mn , Fe or Fe are bound, based on EPR and NMR spectroscopy. However, the mutant's Fe-supported activity is at least 7% that of FeSOD, in contrast to Fe(Mn)SOD, which has 0% of FeSOD's activity. Thus, moving the active site Gln converts Mn-specific SOD into a cambialistic SOD and the Gln proves to be 21 31 1 important but not the sole determinant of metal-ion specificity. Indeed, subtle differences in the spectra of Mn , Fe and H in the 21 presence of Fe distinguish the G77Q, Q146A mut-(Mn)SOD from WT (Mn)SOD, and may prove to be correlated with metal ion 21 21 15 activity. We have directly observed the side chain of the active site Gln in Fe SOD and Fe (Mn)SOD by N NMR. The very different 21 chemical shifts indicate that the active site Gln interacts differently with Fe in the two proteins. Since a shorter distance from Gln to Fe and stronger interaction with Fe correlate with a lower E in Fe(Mn)SOD, Gln has the effect of destabilizing additional electron density m 2 on the metal ion. It may do this by stabilizing OH coordinated to the metal ion.
Conservation science and practice, Dec 11, 2022
The Chiricahua leopard frog (Lithobates chiricahuensis) is a threatened species endemic to the so... more The Chiricahua leopard frog (Lithobates chiricahuensis) is a threatened species endemic to the southwestern United States and Northern Mexico. Captive breeding programs were established to support reintroduction efforts, yet reproductive output has been lower than needed for recovery of the species. This study aimed to evaluate the effects of captivity on amphibian reproduction by (1) determining if captive, semi‐captive, and wild male L. chiricahuensis produce sperm at similar rates and concentration in response to hormone treatment; and (2) evaluating the quality of sperm obtained over time from these populations. Males from captive, semi‐captive, and wild locations were administered a combination of human chorionic gonadotropin and gonadotropin‐releasing hormone to stimulate sperm production and release. A high percentage of males in the captive (60%), semi‐captive (100%), and wild (95.3%) populations produced sperm following treatment. Sperm quality (forward progressive motility and total sperm motility) did not differ between groups. However, sperm quantity (sperm/ml) differed (p < .05) between populations, with semi‐captive and wild males producing higher concentrations of sperm than captive males. These results suggest that Chiricahua leopard frog sperm quantity, but not quality, may become negatively impacted by long‐term captivity in indoor, controlled settings.
Animals, Dec 23, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Reproduction, Fertility and Development, 2020
The occurrence of intrauterine growth restriction (IUGR) is a great concern in animal production ... more The occurrence of intrauterine growth restriction (IUGR) is a great concern in animal production systems, leading to substantial economic losses. The multifactorial causes of IUGR make their prediction before or during pregnancy a challenging task. The amniotic fluid, containing chemical secretions of both the developing fetus and the amnion-allantois membrane, may offer a unique opportunity to investigate the causes of IUGR in piglets. Here we applied near-infrared spectroscopy (NIRS) as a rapid tool to discriminate the chemical composition of the amniotic fluid from IUGR fetuses at different gestational ages. The uteri of gravid sows were dissected at 60% (n=6 sows) and 90% (n=6 sows) of gestational age. Amniotic fluids were collected with a sterile 10-mL syringe connected to an 18-G needle under visual guidance, and samples without blood contamination were kept at 4°C while the fetus was measured. Samples were selected according to fetal weight and were classified as small (mean − 2 SD), medium (mean), and large (mean + 2 SD) sizes in each litter. Selected samples were kept at −80°C until NIRS transmittance spectra collection (350-2500nm). At 60% of gestational age, male fetuses weighed 96±1.2, 133±1.7, and 159±1.9g and female fetuses weighed 117±1.1, 137±1.8, and 152±1.8g for small, medium, and large groups, respectively. The fetal weights at 90% of gestational age averaged 517±0.6, 757±0.6, and 912±0.7g for males and 532±0.6, 718±0.9, and 911±0.6g for females for small, medium, and large sizes, respectively. Chemometric analysis of the amniotic fluid spectra was applied to the wavelength range 1300-1600nm using a balanced data set (n=425) with an 80/20 calibration/validation distribution for linear discriminant analysis (LDA-PCA). Overall, we were able to discriminate samples according to fetal size and gestational age; LDA-PCA showed the highest size classification occurring with spectra derived from the small fetuses with an accuracy of 94.5-100% and 100% and 70.6% for the calibration and validation processes from 60% and 90% of gestational age, respectively. By contrast, when the analysis considered each sex at 60% of gestational age, the medium and small fetuses presented the highest size classification for females and males correspondingly. At 90% of gestational age, the large fetuses presented the best discrimination for both sexes. In conclusion, we were able to detect and discriminate chemical changes of the amniotic fluid from different fetuses using NIRS, indicating that this fluid contains molecules that may characterise IUGR in piglets. These observations will permit future investigations to identify specific molecules associated with IUGR that would lead to possible real-time corrective actions before birth. This work was supported by USDA-ARS grant no. 58-6402-3-018.
Reproduction, Fertility and Development, 2017
In vitro fertilization is optimized when there is a homogenous population of viable spermatozoa, ... more In vitro fertilization is optimized when there is a homogenous population of viable spermatozoa, not subjected toxic waste products of apoptotic cells. In a previous study, we developed a “nanopurification” technique to magnetically target and remove non-viable spermatozoa from a boar insemination dose. Nanopurified semen has successfully been studied with IVF in swine and bovine but lacks health data regarding offspring produced from exposed semen. Developmental health performance in mammals is typically assessed through measurements of immune related biomolecules in plasma (e.g. immunoglobulins), quantifying each variable with a specific analytical assay. Recent developments in aqueous based near infrared spectroscopy (NIR), aquaphotomics, have been shown to distinguish reproductive stages (e.g. oestrus, diestrus) in blood serum. Thus, application of aquaphotomics may be ideal for analysis of offspring resulting from fertilization with nanopurified semen, using serum or plasma. Our study objective was to identify holistic differences in blood plasma by characterising NIR spectral profiles in offspring produced from nanopurified semen. Extended boar semen doses were mixed with or without specific nanoparticles to target non-viable spermatozoa. Semen doses were exposed to an electromagnetic field, noninvasively separating non-viable spermatozoa from the insemination dose. Six gilts were bred with (n = 3) or without (n = 3) nanopurified semen. Following birth and weaning, 20 offspring of equal sexes were randomly selected from control and nanopurified litters (10/group) for growth and developmental measurements up until market weight. Blood plasma was collected from offspring at market weight for NIR analysis. Spectral data were collected with a quartz cuvette and ASD FieldSpec® 3 spectrophotometer (ASD Inc., Boulder, CO, USA). Chemometric analysis (Unscrambler® X version 10.4; CAMO Software, Oslo, Norway) included a Savistsky-Golay 1st and 2nd derivative for detection of distinct spectral features. Principal component analysis and partial least-squares block-discrimination were used to examine treatment effects, in a blind experiment. Plasma spectral profiles from control and nanopurified offspring contained 6 shared peaks at 1360, 1373, 1402, 1404, 1422, and 1428 nm. Principle components 1 and 2 accounted for 96.26% of the total variance, with no separation of principal component analysis scores for plasma spectra between groups. Partial least-squares discriminant analysis metrics (slope = 0.026, SECV = 0.52) and Students t-test showed no significant difference (P = 0.57) between groups. Results indicate blood plasma content is not influenced in nanopurified offspring when compared with the control. In addition, solute NIR has shown to be a valuable promising tool for assessing complex aqueous solutions in swine. Further effects on growth and development from offspring born from nanopurified continue to be investigated. This work was supported by USDA-ARS Biophotonics Initiative grant #58–6402–3-018.
Reproduction, Fertility and Development, 2017
Aquaphotomics is a branch of near-infrared (NIR) spectroscopy in which bond vibrations from organ... more Aquaphotomics is a branch of near-infrared (NIR) spectroscopy in which bond vibrations from organic molecules and water create unique spectral absorbance patterns to profile complex aqueous mixtures. Aquaphotomics has been shown to detect virus infected soybean plants from extracts, classify probiotic bacteria, and detect contamination of aquatic ecosystems. We have used aquaphotomics to characterise serum profiles from horses in various phases of the reproductive cycle such as oestrus and diestrus. Because serum is a complex solution of biomolecules, various modes of serum processing (e.g. large protein removal for proteomics or mass spectrometry) may provide different NIR spectral profiles for quantitative analysis of specific compounds or their effects. Zearalenone is a fungal mycotoxin that may have estrogenic potential in mares and is found in feedstuffs. The objectives of this study were to (1) establish NIR spectral profiles of serum and protein-precipitated serum (PPS) collected at peak oestrus from mares; (2) determine if NIR profiles correlate and quantify E2 concentrations in serum or PPS; and (3) determine if NIR can detect differences in serum chemistry of zearalenone-treated mares. Mares were fed zearalenone daily at low (2 mg, 2 mares, 5 cycles) and high (8 mg, 1 mare, 3 cycles) concentrations, plus control (0 mg, 1 mare, 3 cycles). Oestrus cycles were monitored by ultrasound and serum hormone analysis. Serum collected at peak oestrus had E2 values determined by radioimmunoassay (range 0.02–16.87 pg mL−1). Protein precipitated serum had high and medium MW proteins removed with acetonitrile. NIR spectra, collected in triplicate with a 1 mm quartz cuvette and ASD FieldSpec®3 (Boulder, CO, USA), were pre-treated with a Savitsky-Golay 1st derivative for inspection of spectral features, principal component analysis, and partial least-squares regression (PLS) to investigate spectral correlations to E2 concentrations and zearalenone treatment effects. The NIR profiles contrasting serum and PPS at oestrus had distinct spectral features differing significantly at 1320, 1491, 1536, and 1566 nm in the NIR water spectrum, and principal component-1 accounted for 97% of principal component analysis variance in spectra from serum compared to PPS. In the PLS cross-validation linear fit regression model, NIR predicted E2 concentrations (validated by RIA) from serum (slope = 0.89, SECV = 1.92, R2 = 0.81, 3 factors), and from PPS (slope = 0.61; SECV = 1.84, R2 = 0.76, 4 factors). Spectral predictions were poorest at the low E2 threshold, E2 = 0.02 pg mL−1. The PLS model validation metrics of zearalenone dose-dependent effects were also evident in serum (slope = 0.88, SECV = 1.26, R2 = 0.86) and in PPS (slope = 0.67, SECV = 1.96, R2 = 0.66). Correlations of quantitative values of E2 and zearalenone were both better for spectra taken of serum compared to PPS. In summary, NIR spectral profiles of serum chemistry may be able to map E2 hormone levels during reproductive cycling, and these spectra may also have correlations that reflect exposure of mares to estrogenic toxins such as zearalenone. Research was supported by USDA-ARS Biophotonics grant #58-6402-3-018.
Reproduction, Fertility and Development, 2017
The use of nanoparticles both commercially and pharmaceutically has increased over the past decad... more The use of nanoparticles both commercially and pharmaceutically has increased over the past decade, including fluorescent quantum dot nanoparticles (QD) in biochemical research for in vivo imaging. Previous studies have reported the toxic effects of nanoparticles, but their effects on larval metamorphosis and animal development and growth have not been thoroughly examined. Additionally, the method of uptake of nanoparticles by larval systems is unknown. Amphibian larvae are an ideal model for assessing toxicity because of their sensitivity to environmental contaminants and rapid and easily observable developmental stages. We used Anaxyrus fowleri tadpoles to investigate QD (≤ 25 nm diameter) integration into larvae and possible deleterious effects on their growth and development. Tadpoles (A. fowleri; n = 5/group) were placed in 24-well plates containing 1 mL of distilled water and increasing concentrations of QD (0, 1, and 2 nM) 72 h post-hatch. The fluorescence emission of QD in wells was detected at various time points (1, 2, 24, 48, and 72 h) using the in vivo imaging system (IVIS). A subset of tadpoles was killed (MS-222) and sectioned for histopathology. Remaining tadpoles were monitored throughout development. Fluorescence emission of QD in sectioned tadpoles was visualised using an EVOS Cell Imaging System. Developmental metrics of living tadpoles were recorded until metamorphosis. Fluorescence intensity between controls and dosage groups were analysed by ANOVA-1, followed by Student’s l.s.d. test to evaluate the effects of QD concentration and exposure time. The threshold of significance was P &lt; 0.05. The rate of incorporation of QD into tadpoles was determined using the equation y = C + Ao*2(–x/t1/2), where t1/2 is the half-life of QD remaining in solution. The IVIS imaging revealed a rapid decrease of QD fluorescence (total flux) signals from the aqueous tadpole environment. Decreases in fluorescence occurred within 1 h post-exposure and appeared dose and time dependent, with signal nearly gone within 48 h. Half-life of total flux (time necessary for tadpoles to absorb half of the QD in solution) is 20.75 h (R2 = 0.92) and 2.54 h (R2 = 0.96) for 1 nm and 2 nm QD in solution, respectively. The EVOS imaging revealed integration of QD and localization into tadpole tissues. Fluorescence was exclusively found within the mouth, gills, and sections of the intestinal lumen of exposed tadpoles within the first hour. Dose-dependent increases in fluorescence within tissue were observed at each time-point. No signal was observed in controls. In remaining live tadpoles, QD treated tadpoles were smaller in size [t(34) = 2.35, P = 0.024] than controls. Findings reveal that (1) A. fowleri tadpoles integrate and accumulate nanoparticles, without detectable excretion within 72 h post-exposure, and (2) nanoparticles impede normal tadpole development. Ongoing studies are determining the effects of QD exposure on complete tadpole metamorphosis. The work was supported by USDA-ARS Biophotonics Initiative grant #58–6402–3-018.
Scientific Reports
Each year, bovine respiratory disease (BRD) results in significant economic loss in the cattle se... more Each year, bovine respiratory disease (BRD) results in significant economic loss in the cattle sector, and novel metabolic profiling for early diagnosis represents a promising tool for developing effective measures for disease management. Here, 1H-nuclear magnetic resonance (1H-NMR) spectra were used to characterize metabolites from blood plasma collected from male dairy calves (n = 10) intentionally infected with two of the main BRD causal agents, bovine respiratory syncytial virus (BRSV) and Mannheimia haemolytica (MH), to generate a well-defined metabolomic profile under controlled conditions. In response to infection, 46 metabolites (BRSV = 32, MH = 33) changed in concentration compared to the uninfected state. Fuel substrates and products exhibited a particularly strong effect, reflecting imbalances that occur during the immune response. Furthermore, 1H-NMR spectra from samples from the uninfected and infected stages were discriminated with an accuracy, sensitivity, and specifi...
Remote Sensing, 2022
This study develops Near-Infrared Spectroscopy (NIRS) and Mode-Cloning (MC) for the rapid assessm... more This study develops Near-Infrared Spectroscopy (NIRS) and Mode-Cloning (MC) for the rapid assessment of the nutritional quality of bamboo leaves, the primary diet of giant pandas (Ailuropoda melanoleuca) and red pandas (Ailurus fulgens). To test the NIR-MC approach, we evaluated three species of bamboo (Phyllostachys bissetii, Phyllostachys rubromarginata, Phyllostachys aureosulcata). Mode-Cloning incorporated a Slope and Bias Correction (SBC) transform to crude protein prediction models built with NIR spectra taken from Fine–Ground leaves (master mode). The modified models were then applied to spectra from leaves in the satellite minimal processing modes (Course–Ground, Dry–Whole, and Fresh–Whole). The NIR-MC using the SBC yielded a residual prediction deviation (RPD) = 2.73 and 1.84 for Course–Ground and Dry–Whole sample modes, respectively, indicating a good quantitative prediction of crude protein for minimally processed samples that could be easily acquired under field conditio...
Molecules, 2022
Bovine respiratory syncytial virus (BRSV) is a major contributor to respiratory disease in cattle... more Bovine respiratory syncytial virus (BRSV) is a major contributor to respiratory disease in cattle worldwide. Traditionally, BRSV infection is detected based on non-specific clinical signs, followed by reverse transcriptase-polymerase chain reaction (RT-PCR), the results of which can take days to obtain. Near-infrared aquaphotomics evaluation based on biochemical information from biofluids has the potential to support the rapid identification of BRSV infection in the field. This study evaluated NIR spectra (n = 240) of exhaled breath condensate (EBC) from dairy calves (n = 5) undergoing a controlled infection with BRSV. Changes in the organization of the aqueous phase of EBC during the baseline (pre-infection) and infected (post-infection and clinically abnormal) stages were found in the WAMACS (water matrix coordinates) C1, C5, C9, and C11, likely associated with volatile and non-volatile compounds in EBC. The discrimination of these chemical profiles by PCA-LDA models differentiate...
Hormonal priming, induction of ovulation and in-vitro fertilization of the endangered Wyoming toa... more Hormonal priming, induction of ovulation and in-vitro fertilization of the endangered Wyoming toad (Bufo baxteri)
Methods and Protocols, 2021
Biological sex is one of the more critically important physiological parameters needed for managi... more Biological sex is one of the more critically important physiological parameters needed for managing threatened animal species because it is crucial for informing several of the management decisions surrounding conservation breeding programs. Near-infrared spectroscopy (NIRS) is a non-invasive technology that has been recently applied in the field of wildlife science to evaluate various aspects of animal physiology and may have potential as an in vivo technique for determining biological sex in live amphibian species. This study investigated whether NIRS could be used as a rapid and non-invasive method for discriminating biological sex in the endangered Houston toad (Anaxyrus houstonensis). NIR spectra (N = 396) were collected from live A. houstonensis individuals (N = 132), and distinct spectral patterns between males and females were identified using chemometrics. Linear discriminant analysis (PCA-LDA) classified the spectra from each biological sex with accuracy ≥ 98% in the calib...
Reproduction, Fertility and Development, 2020
The occurrence of intrauterine growth restriction (IUGR) is a great concern in animal production ... more The occurrence of intrauterine growth restriction (IUGR) is a great concern in animal production systems, leading to substantial economic losses. The multifactorial causes of IUGR make their prediction before or during pregnancy a challenging task. The amniotic fluid, containing chemical secretions of both the developing fetus and the amnion-allantois membrane, may offer a unique opportunity to investigate the causes of IUGR in piglets. Here we applied near-infrared spectroscopy (NIRS) as a rapid tool to discriminate the chemical composition of the amniotic fluid from IUGR fetuses at different gestational ages. The uteri of gravid sows were dissected at 60% (n=6 sows) and 90% (n=6 sows) of gestational age. Amniotic fluids were collected with a sterile 10-mL syringe connected to an 18-G needle under visual guidance, and samples without blood contamination were kept at 4°C while the fetus was measured. Samples were selected according to fetal weight and were classified as small (mean ...
Reproductive Biology and Endocrinology, 2012
Background: Captive breeding programs for endangered amphibian species often utilize exogenous ho... more Background: Captive breeding programs for endangered amphibian species often utilize exogenous hormones for species that are difficult to breed. The purpose of our study was to compare the efficacy of two different hormones at various concentrations on sperm production, quantity and quality over time in order to optimize assisted breeding. Methods: Male American toads (Anaxyrus americanus) were divided into three separate treatment groups, with animals in each group rotated through different concentrations of luteinizing hormone releasing hormone analog (LHRH; 0.1, 1.0, 4.0 and 32 micrograms/toad), human chorionic gonadotropin (hCG; 50, 100, 200, and 300 IU), or the control over 24 hours. We evaluated the number of males that respond by producing spermic urine, the sperm concentration, percent motility, and quality of forward progression. We also evaluated the effects of hCG and LHRH on reproductive behavior as assessed by amplexus. Data were analyzed using the Generalized Estimating Equations incorporating repeated measures over time and including the main effects of treatment and time, and the treatment by time interaction. Results: The hormone hCG was significantly more effective at stimulating spermiation in male Anaxyrus americanus than LHRH and showed a dose-dependent response in the number of animals producing sperm. At the most effective hCG dose (300 IU), 100% of the male toads produced sperm, compared to only 35% for the best LHRH dose tested (4.0 micrograms). In addition to having a greater number of responders (P < 0.05), the 300 IU hCG treatment group had a much higher average sperm concentration (P < 0.05) than the treatment group receiving 4.0 micrograms LHRH. In contrast, these two treatments did not result in significant differences in sperm motility or quality of forward progressive motility. However, more males went into amplexus when treated with LHRH vs. hCG (90% vs. 75%) by nine hours post-administration. Conclusion: There is a clear dichotomy between the two hormones' physiological responses on gamete production and stimulation of amplexus. Understanding how these two hormones influence physiology and reproductive behaviors in amphibians will have direct bearing on establishing similar breeding protocols for endangered species.
Journal of the American Chemical Society, 2002
The Fe-and Mn-containing superoxide dismutases catalize the same reaction and have almost superim... more The Fe-and Mn-containing superoxide dismutases catalize the same reaction and have almost superimposable active sites. Therefore, the details of their mechanisms have been assumed to be similar. However, we now show that the pH dependence of Escherichia coli MnSOD activity reflects a different active site proton equilibrium in (oxidized) Mn 3+ SOD than the event that affects the active site pK of oxidized FeSOD. We find that the universally conserved Tyr34 that has a pK above 11.5 in Fe 3+ SOD is responsible for the pK near 9.5 of Mn 3+ SOD and, thus, that the oxidized state pK of Mn 3+ SOD corresponds to an outer-sphere event whereas that of Fe 3+ SOD corresponds to an inner sphere event [Bull, C.; Fee, J. A. J. Am. Chem. Soc. 1985, 107, 3295-3304]. We also present the first description of a reduced-state pK for MnSOD. Mn 2+ SOD's pK involves deprotonation of Tyr34, as does Fe 2+ SOD's pK [Sorkin, D. L.; Miller A.-F. Biochemistry 1997, 36, 4916-4924]. However, the values of the pKs, 10.5 and 8.5 respectively, are quite different and Mn 2+ SOD's pK affects the coordination geometry of Mn 2+ , most likely via polarization of the conserved Gln146 that hydrogen bonds to axially coordinated H2O. Our findings are consistent with the different electronic configurations of Mn 2+/3+ vs Fe 2+/3+ , such as the stronger hydrogen bonding between Gln146 and coordinated solvent in MnSOD than that between the analogous Gln69 and coordinated solvent in FeSOD, and the existence of weakly localized H 2O near the sixth coordination site of Mn 2+ in Mn 2+ SOD [Borgstahl et al.
Journal of Inorganic Biochemistry, 2000
We are addressing the puzzling metal ion specificity of Fe-and Mn-containing superoxide dismutase... more We are addressing the puzzling metal ion specificity of Fe-and Mn-containing superoxide dismutases (SODs) [see C.K. Vance, A.-F. Miller, J. Am. Chem. Soc. 120(3) (1998) 461-467]. Here, we test the significance to activity and active site integrity of the Gln side chain at the center of the active site hydrogen bond network. We have generated a mutant of MnSOD with the active site Gln in the location 21 31 21 characteristic of Fe-specific SODs. The active site is similar to that of MnSOD when Mn , Fe or Fe are bound, based on EPR and NMR spectroscopy. However, the mutant's Fe-supported activity is at least 7% that of FeSOD, in contrast to Fe(Mn)SOD, which has 0% of FeSOD's activity. Thus, moving the active site Gln converts Mn-specific SOD into a cambialistic SOD and the Gln proves to be 21 31 1 important but not the sole determinant of metal-ion specificity. Indeed, subtle differences in the spectra of Mn , Fe and H in the 21 presence of Fe distinguish the G77Q, Q146A mut-(Mn)SOD from WT (Mn)SOD, and may prove to be correlated with metal ion 21 21 15 activity. We have directly observed the side chain of the active site Gln in Fe SOD and Fe (Mn)SOD by N NMR. The very different 21 chemical shifts indicate that the active site Gln interacts differently with Fe in the two proteins. Since a shorter distance from Gln to Fe and stronger interaction with Fe correlate with a lower E in Fe(Mn)SOD, Gln has the effect of destabilizing additional electron density m 2 on the metal ion. It may do this by stabilizing OH coordinated to the metal ion.
Journal of Animal Science
Artificial insemination (AI) with fresh semen is the primary breeding tool in the swine industry.... more Artificial insemination (AI) with fresh semen is the primary breeding tool in the swine industry. However, the heterogenous semen doses create challenges in boar studs due to the lack of consistent assessment criteria. Seminal plasma (SP) surrounding spermatozoa is a great source of reliable non-invasive biomarkers of sperm quality. It contains a wide array of bioactive molecules, whose dynamic compositions in response to extrinsic and intrinsic factors influence sperm motility and morphology. Therefore, we hypothesize that the miRNA content of extracellular vesicles (EVs) found in SP may reflect semen quality. Our study aimed to characterize poor vs. good quality semen and compare miRNA profiles of SP-derived EVs. Raw semen was collected (n = 75) from sexually mature Duroc boars at a commercial stud (Prestage Farms, MS) for 8 weeks. Semen samples were subjected to sperm motility and morphology analyses and subsequently classified as poor (n = 38) or good (n = 37) quality based on a...
Reproduction, Fertility and Development, 2017
The capability of near-infrared spectroscopy (NIR) to detect biomolecules in aqueous solutions, a... more The capability of near-infrared spectroscopy (NIR) to detect biomolecules in aqueous solutions, a sub-field of NIR called aquaphotomics, has yet to be fully explored. Aquaphotomics references water absorbance patterns and wavelength shifts in the 1st overtone of the water spectrum as they change patterns with solute composition and concentrations. Recently, NIR was used as a rapid method for detecting oestrus in Holstein raw milk and for monitoring reproductive stages in urine of the Bornean Orangutan (Pongo pygmaeus) and the giant panda (Ailuropoda melanoleuca). Near-infrared spectroscopy detects bond vibrations from organic molecules and water to create unique absorbance patterns, which are used to profile complex mixtures of biomolecules. The objectives of this study are to (1) characterise serum NIR spectral profiles for oestrus, metestrus, and diestrus in mares, and (2) determine if NIR can accurately decipher these reproductive phases from serum due to the biochemical effects of reproductive hormones. Mare oestrus cycles were assessed every other day by ultrasound and serum hormone analysis. Serum was collected via jugular venipuncture on day 0, 2, 4, 8, and 16 of each cycle for 3 consecutive cycles from each mare. Radioimmunoassay analysis of reproductive hormones E2 and P4 was used to validate and characterise the NIR spectra. Spectra were collected from triplicate samples of 200 μL of serum in a 1-mm-path-length quartz cuvette with an ADS FieldSpec®3 spectrophotometer, at room temperature (22°C). Chemometric analysis (Unscrambler® X v.10.4; CAMO Software) included pretreatment with a Savitsky-Golay second-derivative function for visual inspection of spectral features and principal component analysis (PCA), after mean centering, for distinction of reproductive status. Spectral peaks at 1347, 1367, and 1465 nm were unique to serum collected from mares in oestrus exhibiting high E2 (11.87 to 16.88 pg mL−1). Early metestrus is characterised by prominent spectral peaks at 1383 and 1437 nm, corresponding to E2 levels (0.02 to 5.29 pg mL−1) and P4 levels (0.02 to 3.61 ng mL−1). Diestrus peaks were found at 1342, 1426, and 1473 nm, when P4 levels ranged from 5.14 to 9.60 ng mL−1. In our PCA models, 98% of the total variance in serum spectra between any pair of reproductive phases was described in only 3 spectral PCs, (PC1 = 83–86%, PC2 = 9–10%, PC3 = 2–5% of total variance). The PCA scores separated into distinct groups, indicating clear spectral profiles describing each reproductive phase uniquely. In conclusion, PCA analysis and spectral variances indicate that NIR, specifically aquaphotomics, has the theoretical capability to discriminate complex mixtures of biomolecules present in mare serum during oestrus, metestrus, and diestrus reproductive states. Study was supported by USDA-ARS Biophotonics Initiative grant #58-6402-3-018.
Journal of Inorganic Biochemistry, Jul 1, 2000
We are addressing the puzzling metal ion specificity of Fe-and Mn-containing superoxide dismutase... more We are addressing the puzzling metal ion specificity of Fe-and Mn-containing superoxide dismutases (SODs) [see C.K. Vance, A.-F. Miller, J. Am. Chem. Soc. 120(3) (1998) 461-467]. Here, we test the significance to activity and active site integrity of the Gln side chain at the center of the active site hydrogen bond network. We have generated a mutant of MnSOD with the active site Gln in the location 21 31 21 characteristic of Fe-specific SODs. The active site is similar to that of MnSOD when Mn , Fe or Fe are bound, based on EPR and NMR spectroscopy. However, the mutant's Fe-supported activity is at least 7% that of FeSOD, in contrast to Fe(Mn)SOD, which has 0% of FeSOD's activity. Thus, moving the active site Gln converts Mn-specific SOD into a cambialistic SOD and the Gln proves to be 21 31 1 important but not the sole determinant of metal-ion specificity. Indeed, subtle differences in the spectra of Mn , Fe and H in the 21 presence of Fe distinguish the G77Q, Q146A mut-(Mn)SOD from WT (Mn)SOD, and may prove to be correlated with metal ion 21 21 15 activity. We have directly observed the side chain of the active site Gln in Fe SOD and Fe (Mn)SOD by N NMR. The very different 21 chemical shifts indicate that the active site Gln interacts differently with Fe in the two proteins. Since a shorter distance from Gln to Fe and stronger interaction with Fe correlate with a lower E in Fe(Mn)SOD, Gln has the effect of destabilizing additional electron density m 2 on the metal ion. It may do this by stabilizing OH coordinated to the metal ion.
Conservation science and practice, Dec 11, 2022
The Chiricahua leopard frog (Lithobates chiricahuensis) is a threatened species endemic to the so... more The Chiricahua leopard frog (Lithobates chiricahuensis) is a threatened species endemic to the southwestern United States and Northern Mexico. Captive breeding programs were established to support reintroduction efforts, yet reproductive output has been lower than needed for recovery of the species. This study aimed to evaluate the effects of captivity on amphibian reproduction by (1) determining if captive, semi‐captive, and wild male L. chiricahuensis produce sperm at similar rates and concentration in response to hormone treatment; and (2) evaluating the quality of sperm obtained over time from these populations. Males from captive, semi‐captive, and wild locations were administered a combination of human chorionic gonadotropin and gonadotropin‐releasing hormone to stimulate sperm production and release. A high percentage of males in the captive (60%), semi‐captive (100%), and wild (95.3%) populations produced sperm following treatment. Sperm quality (forward progressive motility and total sperm motility) did not differ between groups. However, sperm quantity (sperm/ml) differed (p < .05) between populations, with semi‐captive and wild males producing higher concentrations of sperm than captive males. These results suggest that Chiricahua leopard frog sperm quantity, but not quality, may become negatively impacted by long‐term captivity in indoor, controlled settings.
Animals, Dec 23, 2022
This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY
Reproduction, Fertility and Development, 2020
The occurrence of intrauterine growth restriction (IUGR) is a great concern in animal production ... more The occurrence of intrauterine growth restriction (IUGR) is a great concern in animal production systems, leading to substantial economic losses. The multifactorial causes of IUGR make their prediction before or during pregnancy a challenging task. The amniotic fluid, containing chemical secretions of both the developing fetus and the amnion-allantois membrane, may offer a unique opportunity to investigate the causes of IUGR in piglets. Here we applied near-infrared spectroscopy (NIRS) as a rapid tool to discriminate the chemical composition of the amniotic fluid from IUGR fetuses at different gestational ages. The uteri of gravid sows were dissected at 60% (n=6 sows) and 90% (n=6 sows) of gestational age. Amniotic fluids were collected with a sterile 10-mL syringe connected to an 18-G needle under visual guidance, and samples without blood contamination were kept at 4°C while the fetus was measured. Samples were selected according to fetal weight and were classified as small (mean − 2 SD), medium (mean), and large (mean + 2 SD) sizes in each litter. Selected samples were kept at −80°C until NIRS transmittance spectra collection (350-2500nm). At 60% of gestational age, male fetuses weighed 96±1.2, 133±1.7, and 159±1.9g and female fetuses weighed 117±1.1, 137±1.8, and 152±1.8g for small, medium, and large groups, respectively. The fetal weights at 90% of gestational age averaged 517±0.6, 757±0.6, and 912±0.7g for males and 532±0.6, 718±0.9, and 911±0.6g for females for small, medium, and large sizes, respectively. Chemometric analysis of the amniotic fluid spectra was applied to the wavelength range 1300-1600nm using a balanced data set (n=425) with an 80/20 calibration/validation distribution for linear discriminant analysis (LDA-PCA). Overall, we were able to discriminate samples according to fetal size and gestational age; LDA-PCA showed the highest size classification occurring with spectra derived from the small fetuses with an accuracy of 94.5-100% and 100% and 70.6% for the calibration and validation processes from 60% and 90% of gestational age, respectively. By contrast, when the analysis considered each sex at 60% of gestational age, the medium and small fetuses presented the highest size classification for females and males correspondingly. At 90% of gestational age, the large fetuses presented the best discrimination for both sexes. In conclusion, we were able to detect and discriminate chemical changes of the amniotic fluid from different fetuses using NIRS, indicating that this fluid contains molecules that may characterise IUGR in piglets. These observations will permit future investigations to identify specific molecules associated with IUGR that would lead to possible real-time corrective actions before birth. This work was supported by USDA-ARS grant no. 58-6402-3-018.
Reproduction, Fertility and Development, 2017
In vitro fertilization is optimized when there is a homogenous population of viable spermatozoa, ... more In vitro fertilization is optimized when there is a homogenous population of viable spermatozoa, not subjected toxic waste products of apoptotic cells. In a previous study, we developed a “nanopurification” technique to magnetically target and remove non-viable spermatozoa from a boar insemination dose. Nanopurified semen has successfully been studied with IVF in swine and bovine but lacks health data regarding offspring produced from exposed semen. Developmental health performance in mammals is typically assessed through measurements of immune related biomolecules in plasma (e.g. immunoglobulins), quantifying each variable with a specific analytical assay. Recent developments in aqueous based near infrared spectroscopy (NIR), aquaphotomics, have been shown to distinguish reproductive stages (e.g. oestrus, diestrus) in blood serum. Thus, application of aquaphotomics may be ideal for analysis of offspring resulting from fertilization with nanopurified semen, using serum or plasma. Our study objective was to identify holistic differences in blood plasma by characterising NIR spectral profiles in offspring produced from nanopurified semen. Extended boar semen doses were mixed with or without specific nanoparticles to target non-viable spermatozoa. Semen doses were exposed to an electromagnetic field, noninvasively separating non-viable spermatozoa from the insemination dose. Six gilts were bred with (n = 3) or without (n = 3) nanopurified semen. Following birth and weaning, 20 offspring of equal sexes were randomly selected from control and nanopurified litters (10/group) for growth and developmental measurements up until market weight. Blood plasma was collected from offspring at market weight for NIR analysis. Spectral data were collected with a quartz cuvette and ASD FieldSpec® 3 spectrophotometer (ASD Inc., Boulder, CO, USA). Chemometric analysis (Unscrambler® X version 10.4; CAMO Software, Oslo, Norway) included a Savistsky-Golay 1st and 2nd derivative for detection of distinct spectral features. Principal component analysis and partial least-squares block-discrimination were used to examine treatment effects, in a blind experiment. Plasma spectral profiles from control and nanopurified offspring contained 6 shared peaks at 1360, 1373, 1402, 1404, 1422, and 1428 nm. Principle components 1 and 2 accounted for 96.26% of the total variance, with no separation of principal component analysis scores for plasma spectra between groups. Partial least-squares discriminant analysis metrics (slope = 0.026, SECV = 0.52) and Students t-test showed no significant difference (P = 0.57) between groups. Results indicate blood plasma content is not influenced in nanopurified offspring when compared with the control. In addition, solute NIR has shown to be a valuable promising tool for assessing complex aqueous solutions in swine. Further effects on growth and development from offspring born from nanopurified continue to be investigated. This work was supported by USDA-ARS Biophotonics Initiative grant #58–6402–3-018.
Reproduction, Fertility and Development, 2017
Aquaphotomics is a branch of near-infrared (NIR) spectroscopy in which bond vibrations from organ... more Aquaphotomics is a branch of near-infrared (NIR) spectroscopy in which bond vibrations from organic molecules and water create unique spectral absorbance patterns to profile complex aqueous mixtures. Aquaphotomics has been shown to detect virus infected soybean plants from extracts, classify probiotic bacteria, and detect contamination of aquatic ecosystems. We have used aquaphotomics to characterise serum profiles from horses in various phases of the reproductive cycle such as oestrus and diestrus. Because serum is a complex solution of biomolecules, various modes of serum processing (e.g. large protein removal for proteomics or mass spectrometry) may provide different NIR spectral profiles for quantitative analysis of specific compounds or their effects. Zearalenone is a fungal mycotoxin that may have estrogenic potential in mares and is found in feedstuffs. The objectives of this study were to (1) establish NIR spectral profiles of serum and protein-precipitated serum (PPS) collected at peak oestrus from mares; (2) determine if NIR profiles correlate and quantify E2 concentrations in serum or PPS; and (3) determine if NIR can detect differences in serum chemistry of zearalenone-treated mares. Mares were fed zearalenone daily at low (2 mg, 2 mares, 5 cycles) and high (8 mg, 1 mare, 3 cycles) concentrations, plus control (0 mg, 1 mare, 3 cycles). Oestrus cycles were monitored by ultrasound and serum hormone analysis. Serum collected at peak oestrus had E2 values determined by radioimmunoassay (range 0.02–16.87 pg mL−1). Protein precipitated serum had high and medium MW proteins removed with acetonitrile. NIR spectra, collected in triplicate with a 1 mm quartz cuvette and ASD FieldSpec®3 (Boulder, CO, USA), were pre-treated with a Savitsky-Golay 1st derivative for inspection of spectral features, principal component analysis, and partial least-squares regression (PLS) to investigate spectral correlations to E2 concentrations and zearalenone treatment effects. The NIR profiles contrasting serum and PPS at oestrus had distinct spectral features differing significantly at 1320, 1491, 1536, and 1566 nm in the NIR water spectrum, and principal component-1 accounted for 97% of principal component analysis variance in spectra from serum compared to PPS. In the PLS cross-validation linear fit regression model, NIR predicted E2 concentrations (validated by RIA) from serum (slope = 0.89, SECV = 1.92, R2 = 0.81, 3 factors), and from PPS (slope = 0.61; SECV = 1.84, R2 = 0.76, 4 factors). Spectral predictions were poorest at the low E2 threshold, E2 = 0.02 pg mL−1. The PLS model validation metrics of zearalenone dose-dependent effects were also evident in serum (slope = 0.88, SECV = 1.26, R2 = 0.86) and in PPS (slope = 0.67, SECV = 1.96, R2 = 0.66). Correlations of quantitative values of E2 and zearalenone were both better for spectra taken of serum compared to PPS. In summary, NIR spectral profiles of serum chemistry may be able to map E2 hormone levels during reproductive cycling, and these spectra may also have correlations that reflect exposure of mares to estrogenic toxins such as zearalenone. Research was supported by USDA-ARS Biophotonics grant #58-6402-3-018.
Reproduction, Fertility and Development, 2017
The use of nanoparticles both commercially and pharmaceutically has increased over the past decad... more The use of nanoparticles both commercially and pharmaceutically has increased over the past decade, including fluorescent quantum dot nanoparticles (QD) in biochemical research for in vivo imaging. Previous studies have reported the toxic effects of nanoparticles, but their effects on larval metamorphosis and animal development and growth have not been thoroughly examined. Additionally, the method of uptake of nanoparticles by larval systems is unknown. Amphibian larvae are an ideal model for assessing toxicity because of their sensitivity to environmental contaminants and rapid and easily observable developmental stages. We used Anaxyrus fowleri tadpoles to investigate QD (≤ 25 nm diameter) integration into larvae and possible deleterious effects on their growth and development. Tadpoles (A. fowleri; n = 5/group) were placed in 24-well plates containing 1 mL of distilled water and increasing concentrations of QD (0, 1, and 2 nM) 72 h post-hatch. The fluorescence emission of QD in wells was detected at various time points (1, 2, 24, 48, and 72 h) using the in vivo imaging system (IVIS). A subset of tadpoles was killed (MS-222) and sectioned for histopathology. Remaining tadpoles were monitored throughout development. Fluorescence emission of QD in sectioned tadpoles was visualised using an EVOS Cell Imaging System. Developmental metrics of living tadpoles were recorded until metamorphosis. Fluorescence intensity between controls and dosage groups were analysed by ANOVA-1, followed by Student’s l.s.d. test to evaluate the effects of QD concentration and exposure time. The threshold of significance was P &lt; 0.05. The rate of incorporation of QD into tadpoles was determined using the equation y = C + Ao*2(–x/t1/2), where t1/2 is the half-life of QD remaining in solution. The IVIS imaging revealed a rapid decrease of QD fluorescence (total flux) signals from the aqueous tadpole environment. Decreases in fluorescence occurred within 1 h post-exposure and appeared dose and time dependent, with signal nearly gone within 48 h. Half-life of total flux (time necessary for tadpoles to absorb half of the QD in solution) is 20.75 h (R2 = 0.92) and 2.54 h (R2 = 0.96) for 1 nm and 2 nm QD in solution, respectively. The EVOS imaging revealed integration of QD and localization into tadpole tissues. Fluorescence was exclusively found within the mouth, gills, and sections of the intestinal lumen of exposed tadpoles within the first hour. Dose-dependent increases in fluorescence within tissue were observed at each time-point. No signal was observed in controls. In remaining live tadpoles, QD treated tadpoles were smaller in size [t(34) = 2.35, P = 0.024] than controls. Findings reveal that (1) A. fowleri tadpoles integrate and accumulate nanoparticles, without detectable excretion within 72 h post-exposure, and (2) nanoparticles impede normal tadpole development. Ongoing studies are determining the effects of QD exposure on complete tadpole metamorphosis. The work was supported by USDA-ARS Biophotonics Initiative grant #58–6402–3-018.
Scientific Reports
Each year, bovine respiratory disease (BRD) results in significant economic loss in the cattle se... more Each year, bovine respiratory disease (BRD) results in significant economic loss in the cattle sector, and novel metabolic profiling for early diagnosis represents a promising tool for developing effective measures for disease management. Here, 1H-nuclear magnetic resonance (1H-NMR) spectra were used to characterize metabolites from blood plasma collected from male dairy calves (n = 10) intentionally infected with two of the main BRD causal agents, bovine respiratory syncytial virus (BRSV) and Mannheimia haemolytica (MH), to generate a well-defined metabolomic profile under controlled conditions. In response to infection, 46 metabolites (BRSV = 32, MH = 33) changed in concentration compared to the uninfected state. Fuel substrates and products exhibited a particularly strong effect, reflecting imbalances that occur during the immune response. Furthermore, 1H-NMR spectra from samples from the uninfected and infected stages were discriminated with an accuracy, sensitivity, and specifi...
Remote Sensing, 2022
This study develops Near-Infrared Spectroscopy (NIRS) and Mode-Cloning (MC) for the rapid assessm... more This study develops Near-Infrared Spectroscopy (NIRS) and Mode-Cloning (MC) for the rapid assessment of the nutritional quality of bamboo leaves, the primary diet of giant pandas (Ailuropoda melanoleuca) and red pandas (Ailurus fulgens). To test the NIR-MC approach, we evaluated three species of bamboo (Phyllostachys bissetii, Phyllostachys rubromarginata, Phyllostachys aureosulcata). Mode-Cloning incorporated a Slope and Bias Correction (SBC) transform to crude protein prediction models built with NIR spectra taken from Fine–Ground leaves (master mode). The modified models were then applied to spectra from leaves in the satellite minimal processing modes (Course–Ground, Dry–Whole, and Fresh–Whole). The NIR-MC using the SBC yielded a residual prediction deviation (RPD) = 2.73 and 1.84 for Course–Ground and Dry–Whole sample modes, respectively, indicating a good quantitative prediction of crude protein for minimally processed samples that could be easily acquired under field conditio...
Molecules, 2022
Bovine respiratory syncytial virus (BRSV) is a major contributor to respiratory disease in cattle... more Bovine respiratory syncytial virus (BRSV) is a major contributor to respiratory disease in cattle worldwide. Traditionally, BRSV infection is detected based on non-specific clinical signs, followed by reverse transcriptase-polymerase chain reaction (RT-PCR), the results of which can take days to obtain. Near-infrared aquaphotomics evaluation based on biochemical information from biofluids has the potential to support the rapid identification of BRSV infection in the field. This study evaluated NIR spectra (n = 240) of exhaled breath condensate (EBC) from dairy calves (n = 5) undergoing a controlled infection with BRSV. Changes in the organization of the aqueous phase of EBC during the baseline (pre-infection) and infected (post-infection and clinically abnormal) stages were found in the WAMACS (water matrix coordinates) C1, C5, C9, and C11, likely associated with volatile and non-volatile compounds in EBC. The discrimination of these chemical profiles by PCA-LDA models differentiate...
Hormonal priming, induction of ovulation and in-vitro fertilization of the endangered Wyoming toa... more Hormonal priming, induction of ovulation and in-vitro fertilization of the endangered Wyoming toad (Bufo baxteri)
Methods and Protocols, 2021
Biological sex is one of the more critically important physiological parameters needed for managi... more Biological sex is one of the more critically important physiological parameters needed for managing threatened animal species because it is crucial for informing several of the management decisions surrounding conservation breeding programs. Near-infrared spectroscopy (NIRS) is a non-invasive technology that has been recently applied in the field of wildlife science to evaluate various aspects of animal physiology and may have potential as an in vivo technique for determining biological sex in live amphibian species. This study investigated whether NIRS could be used as a rapid and non-invasive method for discriminating biological sex in the endangered Houston toad (Anaxyrus houstonensis). NIR spectra (N = 396) were collected from live A. houstonensis individuals (N = 132), and distinct spectral patterns between males and females were identified using chemometrics. Linear discriminant analysis (PCA-LDA) classified the spectra from each biological sex with accuracy ≥ 98% in the calib...
Reproduction, Fertility and Development, 2020
The occurrence of intrauterine growth restriction (IUGR) is a great concern in animal production ... more The occurrence of intrauterine growth restriction (IUGR) is a great concern in animal production systems, leading to substantial economic losses. The multifactorial causes of IUGR make their prediction before or during pregnancy a challenging task. The amniotic fluid, containing chemical secretions of both the developing fetus and the amnion-allantois membrane, may offer a unique opportunity to investigate the causes of IUGR in piglets. Here we applied near-infrared spectroscopy (NIRS) as a rapid tool to discriminate the chemical composition of the amniotic fluid from IUGR fetuses at different gestational ages. The uteri of gravid sows were dissected at 60% (n=6 sows) and 90% (n=6 sows) of gestational age. Amniotic fluids were collected with a sterile 10-mL syringe connected to an 18-G needle under visual guidance, and samples without blood contamination were kept at 4°C while the fetus was measured. Samples were selected according to fetal weight and were classified as small (mean ...
Reproductive Biology and Endocrinology, 2012
Background: Captive breeding programs for endangered amphibian species often utilize exogenous ho... more Background: Captive breeding programs for endangered amphibian species often utilize exogenous hormones for species that are difficult to breed. The purpose of our study was to compare the efficacy of two different hormones at various concentrations on sperm production, quantity and quality over time in order to optimize assisted breeding. Methods: Male American toads (Anaxyrus americanus) were divided into three separate treatment groups, with animals in each group rotated through different concentrations of luteinizing hormone releasing hormone analog (LHRH; 0.1, 1.0, 4.0 and 32 micrograms/toad), human chorionic gonadotropin (hCG; 50, 100, 200, and 300 IU), or the control over 24 hours. We evaluated the number of males that respond by producing spermic urine, the sperm concentration, percent motility, and quality of forward progression. We also evaluated the effects of hCG and LHRH on reproductive behavior as assessed by amplexus. Data were analyzed using the Generalized Estimating Equations incorporating repeated measures over time and including the main effects of treatment and time, and the treatment by time interaction. Results: The hormone hCG was significantly more effective at stimulating spermiation in male Anaxyrus americanus than LHRH and showed a dose-dependent response in the number of animals producing sperm. At the most effective hCG dose (300 IU), 100% of the male toads produced sperm, compared to only 35% for the best LHRH dose tested (4.0 micrograms). In addition to having a greater number of responders (P < 0.05), the 300 IU hCG treatment group had a much higher average sperm concentration (P < 0.05) than the treatment group receiving 4.0 micrograms LHRH. In contrast, these two treatments did not result in significant differences in sperm motility or quality of forward progressive motility. However, more males went into amplexus when treated with LHRH vs. hCG (90% vs. 75%) by nine hours post-administration. Conclusion: There is a clear dichotomy between the two hormones' physiological responses on gamete production and stimulation of amplexus. Understanding how these two hormones influence physiology and reproductive behaviors in amphibians will have direct bearing on establishing similar breeding protocols for endangered species.
Journal of the American Chemical Society, 2002
The Fe-and Mn-containing superoxide dismutases catalize the same reaction and have almost superim... more The Fe-and Mn-containing superoxide dismutases catalize the same reaction and have almost superimposable active sites. Therefore, the details of their mechanisms have been assumed to be similar. However, we now show that the pH dependence of Escherichia coli MnSOD activity reflects a different active site proton equilibrium in (oxidized) Mn 3+ SOD than the event that affects the active site pK of oxidized FeSOD. We find that the universally conserved Tyr34 that has a pK above 11.5 in Fe 3+ SOD is responsible for the pK near 9.5 of Mn 3+ SOD and, thus, that the oxidized state pK of Mn 3+ SOD corresponds to an outer-sphere event whereas that of Fe 3+ SOD corresponds to an inner sphere event [Bull, C.; Fee, J. A. J. Am. Chem. Soc. 1985, 107, 3295-3304]. We also present the first description of a reduced-state pK for MnSOD. Mn 2+ SOD's pK involves deprotonation of Tyr34, as does Fe 2+ SOD's pK [Sorkin, D. L.; Miller A.-F. Biochemistry 1997, 36, 4916-4924]. However, the values of the pKs, 10.5 and 8.5 respectively, are quite different and Mn 2+ SOD's pK affects the coordination geometry of Mn 2+ , most likely via polarization of the conserved Gln146 that hydrogen bonds to axially coordinated H2O. Our findings are consistent with the different electronic configurations of Mn 2+/3+ vs Fe 2+/3+ , such as the stronger hydrogen bonding between Gln146 and coordinated solvent in MnSOD than that between the analogous Gln69 and coordinated solvent in FeSOD, and the existence of weakly localized H 2O near the sixth coordination site of Mn 2+ in Mn 2+ SOD [Borgstahl et al.
Journal of Inorganic Biochemistry, 2000
We are addressing the puzzling metal ion specificity of Fe-and Mn-containing superoxide dismutase... more We are addressing the puzzling metal ion specificity of Fe-and Mn-containing superoxide dismutases (SODs) [see C.K. Vance, A.-F. Miller, J. Am. Chem. Soc. 120(3) (1998) 461-467]. Here, we test the significance to activity and active site integrity of the Gln side chain at the center of the active site hydrogen bond network. We have generated a mutant of MnSOD with the active site Gln in the location 21 31 21 characteristic of Fe-specific SODs. The active site is similar to that of MnSOD when Mn , Fe or Fe are bound, based on EPR and NMR spectroscopy. However, the mutant's Fe-supported activity is at least 7% that of FeSOD, in contrast to Fe(Mn)SOD, which has 0% of FeSOD's activity. Thus, moving the active site Gln converts Mn-specific SOD into a cambialistic SOD and the Gln proves to be 21 31 1 important but not the sole determinant of metal-ion specificity. Indeed, subtle differences in the spectra of Mn , Fe and H in the 21 presence of Fe distinguish the G77Q, Q146A mut-(Mn)SOD from WT (Mn)SOD, and may prove to be correlated with metal ion 21 21 15 activity. We have directly observed the side chain of the active site Gln in Fe SOD and Fe (Mn)SOD by N NMR. The very different 21 chemical shifts indicate that the active site Gln interacts differently with Fe in the two proteins. Since a shorter distance from Gln to Fe and stronger interaction with Fe correlate with a lower E in Fe(Mn)SOD, Gln has the effect of destabilizing additional electron density m 2 on the metal ion. It may do this by stabilizing OH coordinated to the metal ion.