Quail Research Papers - Academia.edu (original) (raw)

The earliest signs of the lymphatic vascular system are the lymph sacs, which develop adjacent to specific embryonic veins. It has been suggested that sprouts from the lymph sacs form the complete lymphatic vascular system. We have... more

The earliest signs of the lymphatic vascular system are the lymph sacs, which develop adjacent to specific embryonic veins. It has been suggested that sprouts from the lymph sacs form the complete lymphatic vascular system. We have studied the origin of the jugular lymph sacs (JLS), the dermal lymphatics and the lymph hearts of avian embryos. In day 6.5 embryos, the JLS is an endothelial-lined sinusoidal structure. The lymphatic endothelial cells (LECs) stain (in the quail) positive for QH1 antibody and soybean agglutinin. As early as day 4, the anlagen of the JLS can be recognized by their Prox1 expression. Prox1 is found in the jugular section of the cardinal veins, and in scattered cells located in the dermatomes along the cranio-caudal axis and in the splanchnopleura. In the quail, such cells are positive for Prox1 and QH1. In the jugular region, the veins co-express the angiopoietin receptor Tie2. Quail-chick-chimera studies show that the peripheral parts of the JLS form by integration of cells from the paraxial mesoderm. Intravenous application of DiI-conjugated acetylated low-density lipoprotein into day 4 embryos suggests a venous origin of the deep parts of the JLS. Superficial lymphatics are directly derived from the dermatomes, as shown by dermatome grafting. The lymph hearts in the lumbo-sacral region develop from a plexus of Prox1-positive lymphatic capillaries. Both LECs and muscle cells of the lymph hearts are of somitic origin. In sum, avian lymphatics are of dual origin. The deep parts of the lymph sacs are derived from adjacent veins, the superficial parts of the JLS and the dermal lymphatics from local lymphangioblasts.

During the period from July 2002 to June 2003, infectious bursal disease (IBD) was suspected in 101 commercial flocks of broiler chickens on the basis of clinical and post mortem findings in some districts of the Haryana state, India.... more

During the period from July 2002 to June 2003, infectious bursal disease (IBD) was suspected in 101 commercial flocks of broiler chickens on the basis of clinical and post mortem findings in some districts of the Haryana state, India. Bursal samples were collected randomly from 20 flocks for the detection of infectious bursal disease virus (IBDV) by reverse transcription-polymerase chain reaction (RT-PCR) and nested PCR assay. IBDV could be detected in 17 samples as evidenced by amplification of 643 bp fragment of the very variable region of VP2 gene of virus by agarose gel electrophoresis. The authenticity of the amplicons was further confirmed by nested PCR generating amplicons of 552 bp using internal primers.

In a novel assay of angiogenesis in the quail chorioal-(relative to 1.49 { 0.02 and 583 { 60/cm 2 for conlantoic membrane (CAM), we measured vascular pattrols), and of angiostatin-treated samples, 1.43 { 0.02 tern and angiogenic rate... more

In a novel assay of angiogenesis in the quail chorioal-(relative to 1.49 { 0.02 and 583 { 60/cm 2 for conlantoic membrane (CAM), we measured vascular pattrols), and of angiostatin-treated samples, 1.43 { 0.02 tern and angiogenic rate after homogeneous exposure and 424 { 74/cm 2 (relative to 1.50 { 0.02 and 616 { of the entire vascular tree to recognized modulators of 59/cm 2 for controls). To establish normalization valvessel growth. In comparison to phosphate-buffered ues for rates of angiogenesis, we analyzed untreated saline (PBS)-treated controls, the vascular stimulator, CAMs of E6 to E12. From E7 to E10 in skeletonized basic fibroblast growth factor (bFGF or FGF-2), inimages, D f increased linearly from 1.37 { 0.01 to 1.54 creased the rate of angiogenesis by a maximum of { 0.01 and r v from 311 { 67 to 746 { 124/cm 2 (in 72%, whereas a recently discovered angiogenic inhibiboth cases, r 2 Å 1.000). Thus, the rates of normal tor, angiostatin, decreased the rate of vascular growth angiogenic growth as measured by D f and r v were by a maximum of 68%. The perturbants were applied 0.06/day and 138/cm 2-day, respectively. From E10 to in PBS to the CAM of 7-day-old embryos (E7) cultured E12, D f and r v declined slightly. Differences between in petri dishes, and the embryos were cultured further the vasculature of untreated and PBS-treated CAMs until fixation at E8 or E9. For morphometry of the were statistically insignificant. In conclusion, vascuquasi-two-dimensional CAM vasculature, digital imlar branching pattern and density in the quail CAM ages of arterial endpoints from the middle region of were stimulated by bFGF and inhibited by angiothe CAM were acquired in grayscale at a magnification statin. We quantified these changes with statistical of 101, binarized to black/white, and skeletonized. significance by D f and r v , which are expressed relative The pattern of vessel branching was assessed by meato the rates of normal developmental angiogenesis surement of the fractal dimension (D f), and vessel measured for the two parameters in untreated quail density (r v), with the method of grid intersection. embryos. ᭧ 1998 Academic Press Correlations between these two statistical techniques Key Words: angiogenesis; fractal dimension; grid interwere linear (r 2 ranged from 0.967 to 0.985). For skelesection; chorioallantoic membrane; quail; basic fibrotonized images at E9, D f and r v of bFGF-treated samblast growth factor (bFGF); angiostatin. ples were 1.55 { 0.01 and 782 { 26/cm 2 , respectively

The effects of sex and housing on live body weight and carcass characteristics of Coturnix quails were examined in this study. Two hundred day-old quails purchased from local hatcheries were separated according to sexes at three weeks old... more

The effects of sex and housing on live body weight and carcass characteristics of Coturnix quails were examined in this study. Two hundred day-old quails purchased from local hatcheries were separated according to sexes at three weeks old and also divided into cage and deep litter systems. At the end of the 10 week trial, five birds from each sexes and housing were slaughtered, the carcasses were processed and the carcass weight, slaughter weight, dressed weight and other carcass parts were measured. Results showed that the female quail had higher and superior mean values in live body weight and carcass measurements. In addition, females recorded higher weight in edible giblets. With regard to housing system, cage and deep litter did not differ significantly in live body weight and other carcass parts. This implies that both systems of housing are good for rearing quail birds and either could be adopted for profitable and efficient quail meat production. It is suggested that more female quails be raised and produced in large commercial quantities to mitigate the effects of malnutrition prevalent in developing countries as a result of animal protein deficiencies.

I compared the role of ornate plumage, behavior, and body size during male-male competition in two species of New World quail. Gambel's quail (Callipepla gambelii) is a highly ornate and dichromatic species, whereas scaled quail (C.... more

I compared the role of ornate plumage, behavior, and body size during male-male competition in two species of New World quail. Gambel's quail (Callipepla gambelii) is a highly ornate and dichromatic species, whereas scaled quail (C. squamata) is unornamented and monochromatic. During paired contests between unfamiliar males, high rates of testosterone-mediated behaviors (tidbitting, calling) and large body size (mass, tarsus, and tail length) corresponded to winners. In the highly ornate Gambel's quail, male head plumes also influenced the outcome of contests. Plume enhancement made Gambel's quail more likely to win contests, whereas plume removal made males more likely to lose. Plume position also reflected male status. Winning males erected plumes, whereas losers frequently flattened them. Some plumage ornaments, such as belly patches, did not play a primary role during male contests. Unlike static ornaments, head plumes are highly modifiable and likely signal immediate information regarding a male's intent, similar to a coverable badge. Combined, intrasexual selection favored dynamic traits (fast display rates, modifiable ornaments) and static traits (body size) as indicators of male condition or motivation. In scaled quail only, male size was favored both by male-male competition and female choice. Accordingly, the degree of size dimorphism (tarsus length) is greater in scaled than in Gambel's quail. The frequency of overt aggression (chases, pecks, displacement) also differed between species. Gambel's quail were very aggressive, and subordinates often challenged their opponents. In contrast, scaled quail were less aggressive, and subordinates rarely disputed rank. Interspecific comparison indicated differences in the maintenance of male status and possibly in the honesty of signaling. Both appear to be related to differences in social system.

Developmental biology research has used various avian species as model organisms for studying morphogenesis, with the chick embryo being used by the majority of groups. The focus on the chick embryo led Hamburger and Hamilton to develop... more

Developmental biology research has used various avian species as model organisms for studying morphogenesis, with the chick embryo being used by the majority of groups. The focus on the chick embryo led Hamburger and Hamilton to develop their definitive staging series nearly 60 years ago and this series is still the mainstay of all laboratories working with avian embryos. The focus on the chick embryo has somewhat overshadowed the importance of another avian embryo that has proved to be equally powerful, the Japanese quail. Since the late 1960s, chimeras have been produced using chick and quail embryos and this technique has revolutionized the approach taken to the investigation of the cellular and molecular interactions that occur during development. Reviews of the literature demonstrate that many research groups are using the quail embryo in a number of established and new ways, and this species has become a primary animal model in developmental biology. Some staging of quail has been performed but this has been incomplete and variations in descriptions, stages and incubation timings mean that comparisons with the chick are not always easily made. There appears to be general agreement that, at the early stages of embryogenesis, there is little developmental difference between chick and quail embryos, although the basis for this has not been established experimentally. The accelerated ontogeny of quail embryos at mid to late stages of development means that registration with the chick is lost. We have therefore developed a definitive developmental stage series for Japanese quail so that differences are fully characterized, misconceptions or assumptions are avoided, and the results of comparative studies are not distorted.

The cellular origin of fibronectin in the kidney was studied in three experimental models. Immunohistochemical techniques that use cross-reacting or species-specific antibodies against mouse or chicken fibronectin were employed. In the... more

The cellular origin of fibronectin in the kidney was studied in three experimental models. Immunohistochemical techniques that use cross-reacting or species-specific antibodies against mouse or chicken fibronectin were employed. In the first model studied, initially avascular mouse kidneys cultured on avian chorioallantoic membranes differentiate into epithelial kidney tubules and become vascularized by chorioallantoic vessels. Subsequently, hybrid glomeruli composed of mouse podocytes and avian endothelial-mesangial cells form. In immunohistochemical studies, cross-reacting antibodies to fibronectin stained vascular walls, tubular basement membranes, interstitium, and glomeruli of mouse kidney grafts. The species-specific antibodies reacting only with mouse fibronectin stained interstitial areas and tubular basement membranes, but showed no reaction with hybrid glomeruli and avian vascular walls. In contrast, species-specific antibodies against chicken fibronectin stained both the ...

The effect of the dietary supplementation of Mannan Oligosaccharides (MOS) and the acidifier Calcium Propionate (CP) on the performance and carcass quality of the Japanese quail (Coturnix japonica) was investigated in this... more

The effect of the dietary supplementation of Mannan Oligosaccharides (MOS) and the acidifier Calcium Propionate (CP) on the performance and carcass quality of the Japanese quail (Coturnix japonica) was investigated in this experimentation. Three hundred, one-day old Japanese quail divided into four groups with three subgroups each were fed a basal diet that served as control, or a basal diet containing 6 g/kg CP, or 1 g/kg MOS or 1 g/kg MOS plus 6 g/kg CP. The body weight, feed consumption, feed conversion ratio and mortality of the birds were calculated at weekly intervals. On last day of the growing period (day 42) the birds were slaughtered, the carcasses were processed and the carcass weight, carcass dressing percentage and carcass parts percentage were calculated. Furthermore, the breast meat composition and its fatty acid profile were analyzed. The results of the experimentation showed that the addition of MOS in the feed of growing quail significantly (p<0.050) increased the body weight on second week and the feed consumption on second and fourth weeks, while it decreased the liver to live weight percentage and the palmitic acid content of the breast meat. Moreover, the addition of CP in the feed significantly (p<0.050) decreased the feed consumption on fifth week and the heart to live weight percentage. Significant (p<0.050) interaction between the examined supplements was observed on the feed consumption, the FCR and the liver to live weight percentage. No adverse effects from the dietary addition of MOS or CP or both were observed on the performance or the carcass quality of the growing quail.

This study discovers the possible effect propolis, royal jelly, bee pollen and Ronozyme supplementation in diets that can be beneficial for Japanese quails (Coturnix coturnix japonica). Total one hundred and sixty Japanese quails at 43... more

This study discovers the possible effect propolis, royal jelly, bee pollen and Ronozyme supplementation in diets that can be beneficial for Japanese quails (Coturnix coturnix japonica). Total one hundred and sixty Japanese quails at 43 days of age were used and divided randomly into 4 replicate groups each containing 32 animals. The experimental groups as follows: control group was feed a basal diet, royal jelly group was added to the water with 500 mg/kg diet, propolis group was feed orally on a basal diet supplemented with 4 g/kg diet, bee pollen group was feed orally on a basal diet supplemented with 1 g/kg diet, Ronozyme group was feed orally a basal diet supplemented with 1 g/kg diet for 74 days. Malondialdehyde (MDA) levels of the yolk were found highest in the control, royal jelly and Ronozyme groups as compared with bee pollen and propolis groups (p<0.05). MDA levels was significantly improved in the bee pollen and propolis groups as compared with royal jelly and Ronozyme groups (p<0.05). In conclusion, this experiment demonstrated that quails supplemented with propolis and bee pollen could produce egg rich. This study will help the researcher to uncover the critical areas of egg quality that many researchers were not able to explore. Thus a new theory on these compounds may be arrived at.

of fasting on the circadian body temperature rhythm of Japanese quail . PHYSIOL BEHAV 66 (1) [137][138][139][140][141][142][143] 1999.-The effect of food deprivation on the body temperature and activity rhythms of quail was assessed in... more

of fasting on the circadian body temperature rhythm of Japanese quail . PHYSIOL BEHAV 66 (1) [137][138][139][140][141][142][143] 1999.-The effect of food deprivation on the body temperature and activity rhythms of quail was assessed in birds exposed to both light-dark (LD) cycles and to continuous darkness (DD). Quail normally exhibit a daily rhythm of body temperature in LD that will persist in DD (that is, the rhythm is circadian). In LD, 3 days' food deprivation caused the body temperature to drop below its normal nighttime levels, whereas daytime body temperature was unaffected. In DD, food deprivation caused the body temperature to drop below normal at all phases of the circadian rhythm of body temperature. Accordingly, the lack of hypothermia during the light phase of the LD cycle following food deprivation must represent a direct exogenous or "masking" effect of light, and is not an endogenous property of the circadian system. Blind birds exposed to LD 12:12 exhibited an entrained body temperature rhythm, and food deprivation caused a drop in body temperature below normal levels during both the light and dark phases of the LD cycle. Accordingly, the masking effects of light observed in normal birds on LD cycles is mediated via retinal photoreceptors and not via extraretinal photoreceptors. Measurements of activity levels before and during fasting indicate that fasting-induced hypothermia cannot be explained simply as a consequence of decreases in activity levels. Food deprivation was also observed to cause significant phase shifts in the endogenous rhythm of body temperature.

Herbst corpuscles were studied in the crural region of perinatal and adult chicken and quail in order to find out their number and dimensions and to learn more about their structure, especially in relation to size. Crural corpuscles are... more

Herbst corpuscles were studied in the crural region of perinatal and adult chicken and quail in order to find out their number and dimensions and to learn more about their structure, especially in relation to size. Crural corpuscles are arrayed in an encapsulated string between tibia and fibula. They are closely packed together; a small number of corpuscles is found apart from the string, often attached to the periost. The strings of corpuscles are approximately 40 mm long in adult chicken and 20 mm long in the quail. The crural region of the chicken contains 382.8 ± 90.9 (mean ± SD) corpuscles, the numbers ranging from 301 to 582; in the quail, the mean number is 119.2 ± 27.9, with a range from 83 to 167 corpuscles. In the chicken, one axon supplies an average of 1.60 corpuscles; in the quail, the relation of axons to corpuscles is approximately 0.92. In both species, final numbers of crural corpuscles are already attained before hatching and no difference is found in the mean number and range of corpuscles between perinatal and adult birds.

Ultrastructural and ultrahistochemical studies were performed on the uterovaginal sperm host glands of the quail (Coturnix coturnixjaponica). The proximal parts of the glandular necks are lined by a pseudostratified epithelium, consisting... more

Ultrastructural and ultrahistochemical studies were performed on the uterovaginal sperm host glands of the quail (Coturnix coturnixjaponica). The proximal parts of the glandular necks are lined by a pseudostratified epithelium, consisting of high columnar ciliated cells and small, irregular shaped, basal cells.

Genetic variations in ovulation rate which occur in different breeds of sheep provide useful models to explore the mechanisms regulating the development of antral follicles. The Booroola gene, an autosomal mutation that affects ovulation... more

Genetic variations in ovulation rate which occur in different breeds of sheep provide useful models to explore the mechanisms regulating the development of antral follicles. The Booroola gene, an autosomal mutation that affects ovulation rate, has been known for over two decades and despite intensive research it has not yet been identified. Using resources from human genome mapping and known data about gene linkage and chromosome location in the sheep, we selected the gene encoding the Bone Morphogenetic Protein receptor (BMPR) type 1 B (ALK-6) as a candidate site for the mutation. The BMPR1B gene in the human is located at the region linked with the Booroola mutation, syntenic to chromosome 6 in the sheep. A fragment of the sheep BMPR1B gene was cloned from an ovarian cDNA and the deduced aminoacid (AA) sequence is over 98% homologous to the known mammalian sequences. cDNA and genomic DNA from 20 Booroola genotypes were screened and two point mutation were found in the kinase domain of the receptor, one at base 746 of the coding region (A in the ++ to a G in FF animals) which results in a change from a glutamine in the wild type to a arginine in the Booroola animals. Another point mutation was identified at position 1113, (C to A) but this mutation does not change the coding aminoacid. The first mutation was confirmed in genomic DNA from 10 ewes from an independent Brazilian flock which segregates the Booroola phenotype. In all instances homozygous FecB gene carrier (n=11) had only the 746 A to G mutation, non gene carriers (n=14) had only the wild type sequence and heterozygote gene carriers (n=5) had both sequences. This mutation in the subdomain 3 of the kinase domain could result in an alteration in the expression and/or phosphorylation of SMADs, resulting in the phenotype characteristic of the Booroola animals which is the 'precocious' development of a large number of small antral follicles resulting in increased ovulation rate.

The experiment reported herein aimed to investigate whether sodium chloride (NaCl) provided through feed and/or drinking water, compared to NaCl provided in feed, affected the live weight (LW), live weight gain (LWG), feed (FI) and water... more

The experiment reported herein aimed to investigate whether sodium chloride (NaCl) provided through feed and/or drinking water, compared to NaCl provided in feed, affected the live weight (LW), live weight gain (LWG), feed (FI) and water intake (WI), feed conversion ratio (FCR), carcass weight (CW) and dressing percentage (DP) of Japanese quails (Coturnix coturnix Japonica). In a randomised block experimental design, a total of 252 one-week-old Japanese quails were allocated randomly into 4 treatment groups. Each treatment group consisted of three replicates and 21 quails within each replication. The quail chickens were reared in ground cages (75 cm by 75 cm) over a 35-day experimental period. They were offered ad libitum a basal ration the composition of which was 23.97% crude protein and 3083 kcal ME/kg. Treatments were i) 2.5 g NaCl/kg supplemented in feed (control group; C), ii) 2.5 g NaCl/l supplemented in drinking water (tap water; W), iii) 1.25 g NaCl/l supplemented in feed a...

The present experiment was executed to determine the pathological effects induced by concurrent feeding of butachlor (chloroacetanilide herbicide) in male Japanese quail. For this purpose mature male quail about 4-5 weeks of age were... more

The present experiment was executed to determine the pathological effects induced by concurrent feeding of butachlor (chloroacetanilide herbicide) in male Japanese quail. For this purpose mature male quail about 4-5 weeks of age were procured from the local market and randomly divided into six equal groups (A-F). Butachlor was mixed in corn oil and administered orally for 30 days using crop tube. Four birds from each group were killed at day 10, 20 and 30 of the experiment and blood was collected with and without anticoagulant. The birds in groups (A-D) did not reveal any clinical and behavioral alterations. Clinical signs like watery droppings, dullness, ruffled feather, depression, decrease frequency of crowing, mounting with pen mates and foam production were observed. Maximum intensity of these clinical signs and behavioral alterations were observed in group F throughout the experiment. Significant lower values of erythrocytes, hematocrit percent and hemoglobin were recorded. Significantly increased numbers of erythrocytes with micronuclei, lobed and notched nuclei were observed. Histopathologically, enlarged intertubular space, fewer numbers of round spermatids, necrotic spermatids and admixture of dead spermatids were observed in testes. The results revealed significant increase in serum lactate dehydrogenase (LDH), aspartate transaminase (AST), alanine transaminase (ALT) and urea concentrations. The results of present experimental study indicated that butachlor induces hematobiochemical and testicular changes in birds.

The formation of body segments (somites) in vertebrate embryos is accompanied by molecular oscillations (segmentation clock). Interaction of this oscillator with a wave traveling along the body axis (the clock-and-wavefront model) is... more

The formation of body segments (somites) in vertebrate embryos is accompanied by molecular oscillations (segmentation clock). Interaction of this oscillator with a wave traveling along the body axis (the clock-and-wavefront model) is generally believed to control somite number, size, and axial identity. Here we show that a clock-and-wavefront mechanism is unnecessary for somite formation. Non-somite mesoderm treated with Noggin generates many somites that form simultaneously, without cyclic expression of Notch-pathway genes, yet have normal size, shape, and fate. These somites have axial identity: The Hox code is fixed independently of somite fate. However, these somites are not subdivided into rostral and caudal halves, which is necessary for neural segmentation. We propose that somites are self-organizing structures whose size and shape is controlled by local cell-cell interactions.

We describe a very sensitive and precise assay which allows one to study the metabolism of testosterone (T) in small brain nuclei dissected out according to the method of Palkovits and Brownstein. With this method, the neuroanatomical... more

We describe a very sensitive and precise assay which allows one to study the metabolism of testosterone (T) in small brain nuclei dissected out according to the method of Palkovits and Brownstein. With this method, the neuroanatomical distributions of aromatase, and 5a-and 5fl-reductase activities were studied in adult male quail (Coturnix coturnix japonica). The different enzymes show different neuroanatomical distributions. Production of estradiol-17fl (E2) was highest in the sexually dimorphic nucleus preopticus medialis (POM). We showed previously that the preoptic aromatase activity is higher in male than in female quail. As the POM is a central and very large structure within the preoptic area, the present results suggest a relationship between the neuroanatomical and the biochemical sex differences. By contrast, the production of 5a-DHT was highest in the lateral hypothalamic area (LHY), the bed nucleus of the pallial commissure (BPC) and the lateral septum (SL). The 5fl-reductase activity was highest in the lateral septum and in the ventral part of the archistriatum (AV). Moreover, there was a rostral to caudal decrease in 5fl-reductase activity in the hypothalamus.

migratory stream and arrest at prospective hindbrain Guy's Campus and spinal nerve root entry/exit points (Golding and Co-King's College London hen, 1997; Niederlander and Lumsden, 1996). The only London SE1 1UL known marker of BC cells... more

migratory stream and arrest at prospective hindbrain Guy's Campus and spinal nerve root entry/exit points (Golding and Co-King's College London hen, 1997; Niederlander and Lumsden, 1996). The only London SE1 1UL known marker of BC cells in the mouse embryo is the United Kingdom Krox20 gene, which encodes a zinc finger transcription 2 Unité 368 factor shown to control hindbrain segmentation and de l'Institut National de la Santé PNS myelination (Schneider-Maunoury et al., 1993; Toet de la Recherche Mé dicale pilko et al., 1994; Wilkinson et al., 1989). Its inactivation Biologie Molé culaire du Dé veloppement did not result in any obvious BC cell phenotype in the Ecole Normale Supé rieure spinal cord, preventing investigation of their possible 46 rue d'Ulm function during development (Schneider-Maunoury et 75230 Paris Cedex 05 al., 1993; Topilko et al., 1994). In the chick embryo, BC France cells have been shown to express high levels of Cad-7 in addition to Krox20 (Nakagawa and Takeichi, 1995; Niederlander and Lumsden, 1996).

This research was conducted to determine effects of chitosan oligosaccharides (COS) addition to quail diets on growth, carcass traits, liver and intestinal histology, and intestinal microflora. Two hundred forty Japanese quail chicks were... more

This research was conducted to determine effects of chitosan oligosaccharides (COS) addition to quail diets on growth, carcass traits, liver and intestinal histology, and intestinal microflora. Two hundred forty Japanese quail chicks were distributed among three treatments groups, with four replicates. A group was fed with a basal starter diet for 1-21th and a grower diet for 22-42th days (Control). The experimental groups were fed the same diets, in addition to 75 mg/kg (Trial I) or 150 mg/kg (Trial II) of COS. The final live weights of the quails in the Control and Trial I groups were higher than in the Trial II group. There were no differences among the groups in gain, feed intake, feed conversion, and carcass traits. Steatosis in the Trial II group was less than in the Control and Trial I groups. Crypt depth and villus length were higher in the Trial II group than in the other groups. The number of bacteria and yeast in the intestine were lower in the Trial I and II groups than in the Control group. In conclusion, the addition of 75 mg/kg of COS had no adverse effect on the tested parameters, and it increased the crypt depth, villus length, and beneficially on intestinal microflora

We studied the exposure and effect of the organophosphate insecticides azinphos-methyl and diazinon on adult California quail (Callipepla californica) in an apple orchard in the Okanagan Valley, British Columbia. Cholinesterase activity... more

We studied the exposure and effect of the organophosphate insecticides azinphos-methyl and diazinon on adult California quail (Callipepla californica) in an apple orchard in the Okanagan Valley, British Columbia. Cholinesterase activity was measured in plasma samples (n = 65) collected from 54 individuals either prior to spraying, immediately (< 24 hours) or 10 days after three spray events. Mean plasma cholinesterase levels declined significantly (P < 0.05, n = 12) to 61% of pre-spray mean activity (controls) immediately following the first spray event, but by ten days had recovered to 86% of mean control activity. Subsequent spray events caused no significant declines in mean plasma cholinesterase activity. Four of the 26 quail sampled within 24 h of a spray event exhibited plasma-ChE inhibition exceeding 50% inhibition. Radio-tagged quail (n = 25) were monitored throughout the breeding season to determine use of orchards and detect changes in use patterns resulting from the...

Three dimensional Magnetic Resonance Imaging (MRI) datasets are becoming increasingly important in clinical and research applications because of their inherent signal to noise (SNR) advantages, high resolution and isotropic voxels.... more

Three dimensional Magnetic Resonance Imaging (MRI) datasets are becoming increasingly important in clinical and research applications because of their inherent signal to noise (SNR) advantages, high resolution and isotropic voxels. Despite SNR advantages, some 3D acquisitions may be SNR-limited, particularly in MR microscopy. Historically, both classic filtering and wavelet-based denoising techniques have been performed on a slice-by-slice basis. In principle, adaptive techniques such as best-basis wavelet-packet denoising might offer inherent advantages when performed in 3D, instead of 2D, by tracking through plane "structure" and suppressing noise "pseudostructure." This hypothesis was tested in 10 volumetric MR microscopy datasets from several different MR microscopy atlas projects. 3D waveletpacket denoised images consistently yielded lower minimum mean-square error and subjectively perceived noise power than corresponding 2D denoised images using otherwise identical algorithms and parameters. MR microscopy researchers preferred the denoised images to the unprocessed images for their atlas projects.

Sonic hedgehog (Shh) is a morphogen involved in many developmental processes. Injection of cells (5E1) that produce a Shh-blocking antibody causes an attenuation of the Shh response, and this causes vascular malformations and impaired... more

Sonic hedgehog (Shh) is a morphogen involved in many developmental processes. Injection of cells (5E1) that produce a Shh-blocking antibody causes an attenuation of the Shh response, and this causes vascular malformations and impaired remodeling characterized by hemorrhages and protrusions of the anterior cardinal vein and outflow tract, delayed fusion of the dorsal aortae, impaired branching of the internal carotid artery, and delayed remodeling of the aortic arches. Distribution of smooth muscle cells in the vessel wall is unchanged. In 5E1-injected embryos, we also observed impaired assembly of endothelial cells into vascular tubes, particularly in the sixth branchial arch, around the anterior cardinal vein and around the dorsal aorta. In 5E1-treated embryos, increased numbers of macrophage-like cells, apoptotic cells, and a decreased level of proliferation were observed in head mesenchyme. Together, these observations show that Shh signaling is required at multiple stages for proper vessel formation and remodeling. Developmental

The effects of aurofusarin in the quail diet on the antioxidant systems of the developing embryo are investigated. Thirty eight 45-day-old Japanese quails (Coturnix japonica) were divided into two groups and were fed on a corn-soya diet... more

The effects of aurofusarin in the quail diet on the antioxidant systems of the developing embryo are investigated. Thirty eight 45-day-old Japanese quails (Coturnix japonica) were divided into two groups and were fed on a corn-soya diet or the same diet supplemented with aurofusarin at the level of 26.4 mgykg feed in the form of Fusarium graminearum culture enriched with aurofusarin. Eggs obtained after 7 weeks of feeding were incubated. Samples of quail tissues were collected at day 17 of embryonic development and from day old hatchlings. Antioxidants and malondialdehyde were analysed by HPLC-based methods. Inclusion of aurofusarin in the maternal diet was associated with decreased concentrations of aand g-tocopherols, aand g-tocotrienols, retinol, lutein and zeaxanthin in egg yolk. The vitamin E (tocopherols and tocotrienols) concentration in the liver and yolk sac membrane (YSM) of the day 17 embryos and the hatchlings from aurofusarin-fed group was significantly decreased. Alpha-tocopherol concentration was also reduced in kidney, lung, heart, muscle and brain of day-old quails. In the liver of day-old quails, concentrations of lutein, zeaxanthin, retinol, retinyl linoleate, retinyl oleate, retinyl palmitate and retinyl stearate were also reduced. As a result of these diminished antioxidant concentrations, tissue susceptibility to lipid peroxidation was significantly increased. It is suggested that a compromised antioxidant system of the egg yolk and embryonic tissues could predispose quails to increased mortality at late stages of their embryonic development.

In a study of myofibrillar proteins, Chowrashi and Pepe [1982: J. Cell Biol. 94:565-573] reported the isolation of a new, 85-kD Z-band protein that they named amorphin. We report that partial sequences of purified amorphin protein... more

In a study of myofibrillar proteins, Chowrashi and Pepe [1982: J. Cell Biol. 94:565-573] reported the isolation of a new, 85-kD Z-band protein that they named amorphin. We report that partial sequences of purified amorphin protein indicate that amorphin is identical to phosphorylase, an enzyme important in the metabolism of glycogen. Anti-amorphin antibodies also reacted with purified chicken and rabbit phosphorylase. To explore the basis for phosphorylase's (amorphin's) localization in the Z-bands of skeletal muscles, we reacted biotinylated alpha-actinin with purified amorphin and with purified phosphorylase and found that alpha-actinin bound to each. Radioimmune assays also indicated that phosphorylase (amorphin) bound to alpha-actinin, and, with lower affinity, to F-actin. Negative staining of actin filaments demonstrated that alpha-actinin mediates the binding of phosphorylase to actin filaments. There are several glycolytic enzymes that bind actin (e.g., aldolase, phosphofructokinase, and pyruvate kinase), but phosphorylase is the first one demonstrated to bind alpha-actinin. Localization of phosphorylase in live cells was assessed by transfecting cultures of quail embryonic myotubes with plasmids expressing phosphorylase fused to Green Fluorescent Protein (GFP). This resulted in targeting of the fusion protein to Z-bands accompanied by a diffuse pattern in the cytoplasm. Cell Motil. Cytoskeleton 53: 125-135, 2002. In memoriam: This paper is dedicated to the memory of Barbara Drucker, a valued member of the Pepe laboratory where this project began.

Previous studies have shown that Sonic Hedgehog (Shh) signaling is crucial for the development of the first branchial arch (BA1) into a lower-jaw in avian and mammalian embryos. We have already shown that if Shh expression is precociously... more

Previous studies have shown that Sonic Hedgehog (Shh) signaling is crucial for the development of the first branchial arch (BA1) into a lower-jaw in avian and mammalian embryos. We have already shown that if Shh expression is precociously inhibited in pharyngeal endoderm, neural crest cells migrate to BA1 but fail to survive, and Meckel's cartilage and associated structures do not develop. This phenotype can be rescued by addition of an exogenous source of Shh. To decipher the role of Shh, we explored the consequences of providing an extra source of Shh to the presumptive BA1 territory. Grafting quail fibroblasts engineered to produce Shh (QT6-Shh), at the 5-to 8-somite stage, resulted in the induction of mirror-image extra lower jaws, caudolateral to the normal one. It turns out that the oral opening epithelium, in which Shh, Fgf8 and Bmp4 are expressed in a definite pattern, functions as an organizing center for lower-jaw development. In our experimental design, the extra source of Shh activates Fgf8, Bmp4 and Shh genes in caudal BA1 ectoderm in a spatial pattern similar to that of the oral epithelium, and regularly leads to the formation of two extra lower-jaw-organizing centers with opposite rostrocaudal polarities. These results emphasize the similarities between the developmental processes of the limb and mandibular buds, and show that in both cases Shh-producing cells create a zone of polarizing activity for the structures deriving from them.

The norepinephrine transporter (NET) is a neurotransmitter scavenger and site of drug action in noradrenergic neurons. The aim of this study was to identify mechanisms that regulate NET expression during the development of quail (q)... more

The norepinephrine transporter (NET) is a neurotransmitter scavenger and site of drug action in noradrenergic neurons. The aim of this study was to identify mechanisms that regulate NET expression during the development of quail (q) sympathetic neuroblasts, which develop from neural crest stem cells. Neurotrophin-3 (NT-3) and transforming growth factor beta1 (TGF-beta1) cause an increase of qNET mRNA levels in neural crest cells. When combined, the growth factors are additive in increasing qNET mRNA levels. Both NT-3 and TGF-beta1 are synthesized by neural crest cells. Onset of NET expression precedes the onset of neural crest stem cell emigration from the neural tube. In older embryos, qNET is expressed by several crest-derived and noncrest tissues. The data show that qNET expression in presumptive sympathetic neurons is initiated early in embryonic development by growth factors that are produced by neural crest cells themselves. Moreover, the results support our previous observati...

Cover Image: "Le Sac à Malice" by René Magritte is one the less familiar works by this Belgian surrealist. It was painted in 1946 and represents a surrealistic image of a heart in which obviously something went terribly wrong with... more

Cover Image: "Le Sac à Malice" by René Magritte is one the less familiar works by this Belgian surrealist. It was painted in 1946 and represents a surrealistic image of a heart in which obviously something went terribly wrong with epicardial development. A naked myocardium is seen as well as aberrantly originating coronary arteries. Situated in front of a window, this is perhaps the scene of gazing into future research of cardiac development, and maybe even having opened the curtain on the right by the results presented in this thesis.

We reported previously the characterization of Pax-QNR/Pax-6 products expressed in the avian neuroretina. Five proteins (48, 46, 43, 33, and 32 kDa) were characterized, among which the 33 and 32 kDa proteins are devoid of the paired... more

We reported previously the characterization of Pax-QNR/Pax-6 products expressed in the avian neuroretina. Five proteins (48, 46, 43, 33, and 32 kDa) were characterized, among which the 33 and 32 kDa proteins are devoid of the paired domain. In contrast to the 48-kDa (containing an alternative paired exon 4a) and 46-kDa proteins exclusively located in the nucleus, the 43- (in which the paired exon 5 is spliced out), 33-, and 32-kDa proteins were also found in the cytoplasmic compartment. We report the identification of two nuclear targeting sequences: the basic LKRKLQR region (amino acids 206-212) located in the NH2 terminus of the homeodomain used by the p43 and 33/32 kDa proteins; and the paired exon 5 sequence. A case of human aniridia, where arginine 208 of LKRKLQR is mutated into a tryptophan, has been reported recently. We introduced this mutation into the Pax-QNR p46, p43, and p33/32 proteins. No effect on the nuclear localization or in transactivation potential of the protein...

Yolk testosterone concentrations vary in response to environmental conditions and different testosterone contents can subsequently modify the phenotypic traits of offspring. Apart from effects on growth, proactive behaviour and secondary... more

Yolk testosterone concentrations vary in response to environmental conditions and different testosterone contents can subsequently modify the phenotypic traits of offspring. Apart from effects on growth, proactive behaviour and secondary sexual characteristics, the possible negative impacts of maternal testosterone on the immune system are often considered a limitation for its deposition. The effects of maternal testosterone can be modulated by postnatal environmental conditions, such as the availability of food resources. However, the majority of studies considering the effects of maternal testosterone on the immune system have been conducted under optimum conditions. We evaluated the influence of genetic selection for high (HET) and low (LET) egg testosterone content in Japanese quail on immune responsiveness of offspring to phytohaemagglutinin (PHA) and lipopolysaccharide (LPS) stimulation under severe protein restriction. Protein restriction negatively influenced body weight and...

Mucins are high molecular weight glycoproteins which constitute the major component of the mucus layer and are produce by many epithelial tissues in vertebrates. Osteopontin (OPN) is an adhesive phosphorylated glycoprotein that is... more

Mucins are high molecular weight glycoproteins which constitute the major component of the mucus layer and are produce by many epithelial tissues in vertebrates. Osteopontin (OPN) is an adhesive phosphorylated glycoprotein that is expressed by a broad range of tissues and cells. Although gastric mucins MUC1, MUC5AC, MUC6 and OPN have been widely used in histological studies and in diagnostic pathology in order to diagnose gastric carcinomas, their localizations in the stomach of quail have not yet been studied. In this study, the localizations of MUC1, MUC5AC, MUC6 and OPN in the proventriculus and gizzard of Japanese quail during the post-hatching period were compared at light microscope levels by applying immunohistochemical methods. In all ages studied, the immunoreactivity of MUC5AC was present in the lining epithelium of both folds and superficial proventricular glands in the proventriculus, whereas MUC1, MUC6 and OPN reactivity was found in the oxynticopeptic cells of profound proventricular glands. In addition, some cells in the fold epithelium of the proventriculus showed a positive reaction to OPN. The immunoreactivity of MUC1 in gizzard was different from that of MUC5AC. Although MUC5AC was expressed in the cells of both the surface epithelium and profound glands of the gizzard, MUC1 was only localized in the profound glands of the gizzard. However, MUC6 and OPN immunoreactivity was absent in the gizzard. The results indicated that the differences between the localizations of MUC1, MUC5AC, MUC6 and OPN in quail proventriculus and gizzard may be a reflection of functional differences of stomach parts. Although the biological significances of the expressions of MUC1, MUC5AC, MUC6 and OPN in the quail stomach remains unknown, these notable glycoproteins may be associated with barrier function, host defence, and ⁄ or secretion.

Background: Intoxication due to quail consumption is rarely seen. Such a toxicological syndrome (also called coturnism) occurs during the migration of quails from north to south, when they consume hemlock seeds. The clinical symptoms and... more

Background: Intoxication due to quail consumption is rarely seen. Such a toxicological syndrome (also called coturnism) occurs during the migration of quails from north to south, when they consume hemlock seeds. The clinical symptoms and laboratory results are indicative of acute rhabdomyolysis. Objectives: Acute rhabdomyolysis has a wide range of etiologies. Coturnism is a rare cause of acute rhabdomyolysis that can be lethal due to renal failure and shock. To avoid severe complications, coturnism may be considered if the history is appropriate. Case Report: We report four cases of coturnism from quail consumption; the patients were admitted with some combination of symptoms including muscle tenderness, extremity pain, nausea, and vomiting. They were treated with vigorous isotonic crystalloid hydration and urine alkalinization. Consequently, the laboratory results returned to normal ranges and the clinical symptoms disappeared. Conclusion: Although coturnism is a rarely seen toxicological syndrome that causes rhabdomyolysis, we present this case to increase awareness that it may present with symptoms of muscle tenderness, extremity pain, nausea, and vomiting after quail consumption.

The objective of the present study was to determine if acetylsalicylic acid (ASA) would have further antioxidative e#ects beyond lowering rectal temperature of stressed laying Japanese quail and hence improve its physiological status.... more

The objective of the present study was to determine if acetylsalicylic acid (ASA) would have further antioxidative e#ects beyond lowering rectal temperature of stressed laying Japanese quail and hence improve its physiological status. During summer season when daily high temperatures averaged between-and-0῍ and relative humidity averaged between 0* to 1*῍, four treatment groups of adult Japanese quail each containing three replicates of fifteen females were fed either a control diet containing *῍ ASA or the control diet supplemented with *.*,/, *.*/ or *.+῍ ASA from 2 to +0 wk of age. Rectal body temperature was significantly decreased by feeding *.*/ and *.+῍ ASA. Hen-day egg production was significantly increased for quails fed the diet containing *.*/῍ and *.+῍ ASA. Shell thickness seemed to be thicker at the higher levels of ASA. Serum T-concentration was decreased significantly (Pῌ*.*/) in quails fed *.+῍ ASA (*.-2 ng/ml) in comparison with controls (*.0, ng/ml), but serum T. concentration was not significantly a#ected. Dietary ASA had a positive e#ect on humoral immunity and quails fed *.*/ and *.+῍ ASA had a significantly higher total antibody titer compared to other treatments. ASA treatments caused a significant decrease in serum cholesterol, glucose and hepatic TBARS as an indicator for lipid peroxidation, as well as enhancement in the activity of antioxidative enzymes GSH-Px and SOD in a dose dependent manner. These antioxidative e#ects were accompanied with a significant reduction in corticosterone levels due to ASA treatments. Therefore, it could be concluded that feeding diets containing *.*/ or *.+῍ ASA during the summer season could have potential benefits for poultry welfare and productivity because of reducing body temperature and oxidative stress, which consequently allowing more physiological resources to be used for responding to environmental stressors.

The dependence of the muscle-specific enhancer of the acetylcholine receptor a-subunit gene on other domains of the promoter has been analysed by performing point mutagenesis and modular reconstitution of the enhancer-promoter sequences.... more

The dependence of the muscle-specific enhancer of the acetylcholine receptor a-subunit gene on other domains of the promoter has been analysed by performing point mutagenesis and modular reconstitution of the enhancer-promoter sequences. The enhancer is inactive in the absence of the proximal region containing an Spl binding site and an overlapping G-C homopolymer binding factor site (referred to as GBF). The proximal region can be replaced by an Spl binding site from SV40 or an MEF-2 binding site from the muscle creatine kinase gene. Specific mutation of the Spl site markedly affects transactivation by CMD1 or myogenin. Mutation of the GBF binding site leads to higher promoter activity in primary cultures of chick myotubes or in quail fibroblasts. In addition, binding of a purified Spl protein prevents the binding of GBF in vitro. It is proposed that in the case of the a-subunit promoter, the myogenic factors activate transcription in cooperation with Spl, and that GBF contributes to muscle-specific expression of the promoter by interfering with Spl binding in nonmuscle cells or myoblasts.

Three experiments were carried out to study whether differences in the intracellular metabolism of testosterone (T) can explain sexually differential responses to T in Japanese quail. In the first experiment, a series of dose-response... more

Three experiments were carried out to study whether differences in the intracellular metabolism of testosterone (T) can explain sexually differential responses to T in Japanese quail. In the first experiment, a series of dose-response curves in which length of Silastic testosterone implants was related to effects on several behavioral and physiological variables was established. In Experiment 2, adult males and females were assigned to six experimental groups: intact males and females (I-males and I-females), castrated males and females implanted subcutaneously with 40-mm Silastic implants of T (T-males and T-females), and castrated males and females without hormone treatment (CX-males and CXfemales). No CX-bird (male or female) and no I-female exhibited male sexual behavior. However, I-males and T-males regularly copulated during the behavioral tests. No crowing was ever heard in CX-animals and I-females. T-females crowed less than T-males and their crowing sounded weaker than those of males. The cloaca1 glands of T-females were less deveioped than those of males. Radioimmunoassay of T and So-DHT showed that T-males and T-females have similar plasma levels of androgens. No striking differences were observed in the way testosterone is metabolized by the pituitary gland and central nervous tissues of males and females. By contrast, the production of 5a-dihydrotestosterone (5~ DHT) and 5a-androstane-3a, 17B-dio1&,3a-di01) was higher in the cloaca1 glands of males than in those of females. These sex differences were not detected between T-males and Tfemales. In experiment 3, the cloacal gland of males produced more Se-reduced metabolites than thase of females. The pituitary gland of females also produced more Sp-androstane-3cr,l7Bdiol (.5~,3adiol). In syringeal muscles, the production of SO-dihydrotestosterone (5B-DHT)and $3, 3~diol was higher in females compared to males.

The glomerular capillary architecture of nephrons that include a loop of Henle (looped) and those that lack the loop (loopless) nephrons was examined qualitatively and quantitatively by electron microscopy in Gallus gallus and Callipepla... more

The glomerular capillary architecture of nephrons that include a loop of Henle (looped) and those that lack the loop (loopless) nephrons was examined qualitatively and quantitatively by electron microscopy in Gallus gallus and Callipepla gambelii. The glomerular capillaries of looped nephrons form a dichotomously branched network, while those of loopless nephrons are arranged loosely, and the majority are unbranched. There was no significant difference in the diameter of the glomerular capillaries between looped and loopless nephrons; however, in all cases the diameter of the afferent arteriole was significantly larger than that of the efferent arteriole. Based on size alone, the predicted blood flow rate in the efferent arteriole is 20% that of the afferent arteriole in G. gallus and 7% that of the afferent arteriole in C. gambelii. There

H9N2 avian influenza viruses continue to circulate worldwide; in Asia, H9N2 viruses have caused disease outbreaks and established lineages in land-based poultry. Some H9N2 strains are considered potentially pandemic because they have... more

H9N2 avian influenza viruses continue to circulate worldwide; in Asia, H9N2 viruses have caused disease outbreaks and established lineages in land-based poultry. Some H9N2 strains are considered potentially pandemic because they have infected humans causing mild respiratory disease. In addition, some of these H9N2 strains replicate efficiently in mice without prior adaptation suggesting that H9N2 strains are expanding their host range. In order to understand the molecular basis of the interspecies transmission of H9N2 viruses, we adapted in the laboratory a wildtype duck H9N2 virus, influenza A/duck/Hong Kong/702/79 (WT702) virus, in quail and chickens through serial lung passages. We carried out comparative analysis of the replication and transmission in quail and chickens of WT702 and the viruses obtained after 23 serial passages in quail (QA23) followed by 10 serial passages in chickens (QA23CkA10). Although the WT702 virus can replicate and transmit in quail, it replicates poorly and does not transmit in chickens. In contrast, the QA23CkA10 virus was very efficient at replicating and transmitting in quail and chickens. Nucleotide sequence analysis of the QA23 and QA23CkA10 viruses compared to the WT702 virus indicated several nucleotide substitutions resulting in amino acid changes within the surface and internal proteins. In addition, a 21-amino acid deletion was found in the stalk of the NA protein of the QA23 virus and was maintained without further modification in the QA23CkA10 adapted virus. More importantly, both the QA23 and the QA23CkA10 viruses, unlike the WT702 virus, were able to readily infect mice, produce a large-plaque phenotype, showed faster replication kinetics in tissue culture, and resulted in the quick selection of the K627 amino acid mammalian-associated signature in PB2. These results are in agreement with the notion that adaptation of H9 viruses to land-based birds can lead to strains with expanded host range.

Quail poisoning is known to produce an acute myoglobinuric syndrome called coturnism. The cause of this syndrome is still unknown, although it has been postulated that Galeopsis ladanum L. seeds, in particular lipidic compounds or... more

Quail poisoning is known to produce an acute myoglobinuric syndrome called coturnism. The cause of this syndrome is still unknown, although it has been postulated that Galeopsis ladanum L. seeds, in particular lipidic compounds or stachydrine, are responsible for this toxicity. Thus, we aimed to study the implication of this plant in coturnism in order to explore the physiopathology of the disease, especially with regard to stachydrine and lipidic compounds extracted from seeds. For this purpose, Wistar rats were fed with G. ladanum seed extracts or with quail meat. However, the rhabdomyolysis outbreak could not be reproduced in any case. Therefore, in view of our results and experimental conditions, seeds of G. ladanum and stachydrine do not appear to be the responsible agents of the myopathic outbreak. This conclusion is supported by the following facts: direct administration of extracts of seeds of G. ladanum or stachydrine produces no myotoxicity in rats; G. ladanum seeds are not toxic to quails and meat from quails fed G. ladanum seeds is not toxic to rats.

Migratory cranial neural crest cells differentiate into a wide range of cell types, such as ectomesenchymal tissue (bone and connective tissues) ventrally in the branchial arches and neural tissue (neurons and glia) dorsally. We... more

Migratory cranial neural crest cells differentiate into a wide range of cell types, such as ectomesenchymal tissue (bone and connective tissues) ventrally in the branchial arches and neural tissue (neurons and glia) dorsally. We investigated spatial and temporal changes of migration and differentiation potential in neural crest populations derived from caudal midbrain and rhombomeres 1 and 2 by backtransplanting cells destined for the first branchial arch and trigeminal ganglion from HH8 -HH19 quail into HH7-HH11 chicks. Branchial arch cells differentiated down ectomesenchymal lineages but largely lost both the ability to localize to the trigeminal position and neurogenic differentiation capacity by HH12-HH13, even before the arch is visible, and lost long distance migratory ability around HH17. In contrast, neural crest-derived cells from trigeminal ganglia lost ectomesechymal differentiation potential by HH17. Despite this, they retain the ability to migrate into the branchial arches until at least HH19. However, many of the neural crest-derived trigeminal ganglia cells in the branchial arch localized to the non-neural crest core of the arch from HH13 and older donors. These results suggest that long distance migration ability, finer scale localization, and lineage restriction may not be coordinately regulated in the cranial neural crest population.

Retinoic acid (RA) is essential for both embryonic and adult growth, activating gene transcription via specific nuclear receptors. It is generated, via a retinaldehyde intermediate, from retinol (vitamin A). RA levels require precise... more

Retinoic acid (RA) is essential for both embryonic and adult growth, activating gene transcription via specific nuclear receptors. It is generated, via a retinaldehyde intermediate, from retinol (vitamin A). RA levels require precise regulation by controlled synthesis and catabolism, and when RA concentrations deviate from normal, in either direction, abnormal growth and development occurs. This review describes: (i) how the pattern of RA metabolic enzymes controls the actions of RA; and (ii) the type of abnormalities that result when this pattern breaks down. Examples are given of RA control of the anterior/posterior axis of the hindbrain, the dorsal/ventral axis of the spinal cord, as well as certain sex-specific segments of the spinal cord, using varied animal models including mouse, quail and mosquitofish. These functions are highly sensitive to abnormal changes in RA concentration. In rodents, the control of neural patterning and differentiation are disrupted when RA concentrations are lowered, whereas inappropriately high concentrations of RA result in abnormal development of cerebellum and hindbrain nuclei. The latter parallels the malformations seen in the human embryo exposed to RA due to treatment of the mother with the acne drug Accutane (13-cis RA) and, in cases where the child survives beyond birth, a particular set of behavioural anomalies can be described. Even the adult brain may be susceptible to an imbalance of RA, particularly the hippocampus. This report shows how the properties of RA as a neural induction agent and organizer of segmentation can explain the consequences of RA depletion and overexpression. Control of neural development by RA RA is a neural differentiation agent There is now a vast body of literature that demonstrates that RA induces undifferentiated cells to differentiate into neurons and glia. This has been observed consistently using various strains of embryonic carcinoma (EC) cells and teratocarcinoma cells, and also with stem cells and neuroblastoma cells from both mouse and human (Maden, 2001). Furthermore, when added to cells that are already neuronal and have been cultured either as dissociated cells or organ cultures, then RA can both increase the number of neurites that extend into the culture dish and increase the length of those neurites. This type of