Daniel Sonenshine - Academia.edu (original) (raw)

Papers by Daniel Sonenshine

Experimental and Applied Acarology, 2002

Challenge of Dermacentor variabilis by hemocoel injection with Borrelia burgdorferi but not Bacil... more Challenge of Dermacentor variabilis by hemocoel injection with Borrelia burgdorferi but not Bacillus subtilis or Escherichia coli provoked secretion of two low molecular weight peptides into the hemolymph plasma; the lower band co-migrated with a band previously identified as varisin (a tick defensin). These findings are consistent with reports that D. variabilis controls B. burgdorferi but not B. subtilis or E. coli by defensin-dependent bacteriolysis. Challenge of the tick midgut by capillary artificial feeding with bacteria also provoked expression of multiple low molecular weight peptides. In this case, however, all three bacteria elicited the response. Two bands, including the defensin-like peptide were expressed following challenge with B. subtilis and E. coli, but only the upper band following challenge with B. burgdorferi. Although they appeared intact, these spirochetes were no longer viable suggesting that borreliae in the midgut are controlled by a different method than the lytic response of the D. variabilis hemolymph. DD-RT-PCR revealed multiple mRNAs in the midgut of D. variabilis following challenge with B. burgdorferi, E. coli and Rickettsia montana. Although their identification remains to be determined, the large number of genes expressed in response to bacterial challenge presents intriguing possibilities for explaining the ability of the tick midgut to destroy invading microbes at the cellular level.

Experimental and Applied Acarology, Jul 1, 2005

PLOS ONE

Bacterial endosymbionts are abundantly found in both hard and soft ticks. Occidentia massiliensis... more Bacterial endosymbionts are abundantly found in both hard and soft ticks. Occidentia massiliensis, a rickettsial endosymbiont, was first identified in the soft tick Ornithodoros sonrai collected from Senegal and later was identified in a hard tick Africaniella transversale. In this study, we noted the presence of Occidentia species, designated as Occidentia-like species, in a soft tick O. turicata americanus. Sequencing and phylogenetic analyses of the two genetic markers, 16S rRNA and groEL confirmed the presence of Occidentia-like species in O. turicata americanus ticks. The Occidentia-like species was noted to be present in all developmental stages of O. turicata americanus and in different tick tissues including ovaries, synganglion, guts and salivary gland. The levels of Occidentia-like species 16S rRNA transcripts were noted to be significantly higher in ovaries than in a gut tissue. In addition, Occidentia-like species groEL expression was noted to be significantly higher in ...

Insect Biochemistry and Molecular Biology, Jul 1, 2001

Hemolymph from partially fed virgin D. variabilis females was collected following B. burgdorferi ... more Hemolymph from partially fed virgin D. variabilis females was collected following B. burgdorferi challenge and assayed for antimicrobial activity against Bacillus subtilis and the Bo"elia burgdorjeri. A small inducible cationic peptide was identified by SDS-P AGE in the hemolymph of these ticks as early as 1 h post-challenge. Following purification by a three step procedure involving sequential SepPak elution, reversed phase high performance liquid chromatography (RP-HPLC) and gel electrophoresis, the yield of the active peptide was approximately 0.1% of the total protein in the hemolymph plasma. The molecular weight, 4.2 kDa, was determined by MALDI-TOF mass spectrometry. N-terminal sequencing by the Edman

Fems Microbiology Letters, Dec 1, 2000

Borrelia burgdorferi B31 cultured at 28³C was used to assay the effects of tick hemolymph on oute... more Borrelia burgdorferi B31 cultured at 28³C was used to assay the effects of tick hemolymph on outer surface protein C (OspC) surface expression. Using immunofluorescence, OspC surface expression was shown to increase in cultures treated with hemolymph from both Ixodes scapularis and Dermacentor variabilis, while control samples (non-hemolymph treated) showed no increase in the levels of OspC. Sodium dodecyl sulfate^polyacrylamide gel electrophoresis also showed an increase in OspC from spirochetes exposed to tick hemolymph. In addition, a lower-molecular-mass protein band of unknown identity was also enhanced in the hemolymph-exposed spirochetes. The significance of these effects of tick hemolymph on B. burgdorferi outer surface protein expression is unknown.

Medical and Veterinary Entomology, Jun 1, 2007

The transcript sequence of the Amblyomma americanum (Acari: lxodidae) defensin, termed amercin (a... more The transcript sequence of the Amblyomma americanum (Acari: lxodidae) defensin, termed amercin (amn), has been ascertained and a 219bp amn coding region identified. The gene encodes a 72 amino acid prepropeptide with a putative 37 amino acid mature peptide. •Sequence comparisons with other tick defensins reveal amn to be 6bp shorter than the Jxodes scapularis Linnaeus (Acari: lxodidae) and Dermacentor variabilis (Say) (Acari: lxodidae) defensin sequences. The translated peptide would be two amino acids shorter than these other defensins with one amino acid less in the prepro-region and the other resulting in a shorter mature peptide. The amercin prepropeptide has 60.8% similarity with the/. scapularis prepropeptide and 59.5% similarity with the D. variabilis preprope~tide. The mature amercin peptide has 73. 7% similarity with the mature/. scapularis peptide and 71.1 % similarity with the D. variabilis peptide. In A. americanum, defensin transcript was found in the midgut, fat body, and salivary gland tissues as well as the hemocytes. Defensin transcript was also present in early stage eggs (less than 48hrs old), late stage eggs (approximately two weeks old), larvae, and nymphs of A. americanum and /. scapularis, both of which are vector competent for Borrelia spirochetes.

Emerging Infectious Diseases, May 1, 2011

We report evidence that Amblyomma maculatum tick populations are well established in southeastern... more We report evidence that Amblyomma maculatum tick populations are well established in southeastern Virginia. We found that 43.1% of the adult Gulf Coast ticks collected in the summer of 2010 carried Rickettsia parkeri, suggesting that persons living in or visiting southeastern Virginia are at risk for infection with this pathogen. R ickettsia parkeri is an obligate intracellular bacterium belonging to the spotted fever group of rickettsiae; this organism has recently been found to be pathogenic to humans (1). Infection with R. parkeri can be considered an emerging infectious disease, referred to as R. parkeri rickettsiosis, American Boutonneuse fever, and Tidewater spotted fever. Two confi rmed cases of R. parkeri infections, including the index case in 2002, occurred in southeastern Virginia (1-3). Since then, 20 R. parkeri infections have been reported, mainly from the southern United States (2). In the United States, Amblyomma maculatum (family Ixodidae) ticks, commonly referred to as Gulf Coast ticks, are the only known natural vector of R. parkeri. A. maculatum ticks have been reported from 12 states: Alabama,

Insect Biochemistry and Molecular Biology, Apr 1, 2007

Heat shock cognate 70-kDa protein (RH-Hsc70) was identified from a cDNA library synthesized from ... more Heat shock cognate 70-kDa protein (RH-Hsc70) was identified from a cDNA library synthesized from the sialotranscriptomes of unfed and fed Rhipicephalus haemaphysaloides. The RH-Hsc70 open reading frame is 1950 bp long and encodes a protein that is 649 amino acids in length, with a predicted molecular weight of 71.1 kDa and a theoretical pI of 5.43. RH-Hsc70 exhibits 98% amino acid identity with Hsc70 in Haemaphysalis flava and 83% identity with Hsc70 in arthropods and mammals. RH-Hsc70 was mainly expressed in nymphs and adult ticks, not in larvae. Real-time quantitative PCR analysis indicated that RH-Hsc70 mRNA expression was induced by blood feeding in adult ticks. In addition, RH-Hsc70 gene expression was higher in the ovaries of fed adult ticks than that in the midguts, salivary glands, and fat bodies of unfed or fed adult ticks. RH-Hsc70 gene knockdown inhibited tick blood feeding, significantly decreased tick engorgement rate, and increased tick death rate. These data illustrate the importance of RH-Hsc70 in tick blood feeding and aging, which makes it a promising candidate for the development of anti-tick vaccines.

$Research paper thumbnail of Antibodies Against EGF-Like Domains in \u3ci\u3eIxodes scapularis\u3c/i\u3e BM86 Orthologs Impact Tick Feeding and Survival of \u3ci\u3eBorrelia burgdorferi\u3c/i\u3e$

Ixodes scapularis ticks transmit multiple pathogens, including Borrelia burgdorferi sensu stricto... more Ixodes scapularis ticks transmit multiple pathogens, including Borrelia burgdorferi sensu stricto, and encode many proteins harboring epidermal growth factor (EGF)-like domains. We show that I. scapularis produces multiple orthologs for Bm86, a widely studied tick gut protein considered as a target of an anti-tick vaccine, herein termed as Is86. We show that Is86 antigens feature at least three identifiable regions harboring EGF-like domains (termed as EGF-1, EGF-2, and EGF-3) and are differentially upregulated during B. burgdorferi infection. Although the RNA interference-mediated knockdown of Is86 genes did not show any influences on tick engorgement or B. burgdorferi sensu stricto persistence, the immunization of murine hosts with specific recombinant EGF antigens marginally reduced spirochete loads in the skin, in addition to affecting tick blood meal engorgement and molting. However, given the borderline impact of EGF immunization on tick engorgement and pathogen survival in th...

Scientific Reports, 2021

Ixodes scapularisticks transmit multiple pathogens, includingBorrelia burgdorferisensu stricto, a... more Ixodes scapularisticks transmit multiple pathogens, includingBorrelia burgdorferisensu stricto, and encode many proteins harboring epidermal growth factor (EGF)-like domains. We show thatI. scapularisproduces multiple orthologs for Bm86, a widely studied tick gut protein considered as a target of an anti-tick vaccine, herein termed as Is86. We show that Is86 antigens feature at least three identifiable regions harboring EGF-like domains (termed as EGF-1, EGF-2, and EGF-3) and are differentially upregulated duringB. burgdorferiinfection. Although the RNA interference-mediated knockdown ofIs86genes did not show any influences on tick engorgement orB. burgdorferisensu stricto persistence, the immunization of murine hosts with specific recombinant EGF antigens marginally reduced spirochete loads in the skin, in addition to affecting tick blood meal engorgement and molting. However, given the borderline impact of EGF immunization on tick engorgement and pathogen survival in the vector, i...

Scientific Reports, 2020

The different components of the mouthparts of hard ticks (Ixodidae) enable these parasites to pen... more The different components of the mouthparts of hard ticks (Ixodidae) enable these parasites to penetrate host skin, secrete saliva, embed, and suck blood. Moreover, the tick’s mouthparts represent a key route for saliva-assisted pathogen transmission as well as pathogen acquisition from blood meal during the tick feeding process. Much has been learned about the basic anatomy of the tick’s mouthparts and in the broad outlines of how they function in previous studies. However, the precise mechanics of these functions are little understood. Here, we propose for the first time an animated model of the orchestration of the tick mouthparts and associated structures during blood meal acquisition and salivation. These two actions are known to alternate during tick engorgement. Specifically, our attention has been paid to the mechanism underlining the blood meal uptake into the pharynx through the mouth and how ticks prevent mixing the uptaken blood with secreted saliva. We animated function...

Journal of Medical Entomology, 1989

The chemical basis for the ability of fed males of Dermacentor variabilis (Say) and D. andersoni ... more The chemical basis for the ability of fed males of Dermacentor variabilis (Say) and D. andersoni (Stiles) to differentiate conspecific and heterospecific females was investigated using a neutered female bioassay. Male D. variabilis responded strongly in a dose-response manner to increasing concentrations of stearic and palmitic acids and an extract of the anterior reproductive tract (ART) of fed D. variabilis females. Mating responses were greatest at 1 microgram of fatty acid and 1 female equivalent (FE) of ART extract. D. variabilis males also responded strongly to D. variabilis females treated with a conspecific ART extract and a mixture of fatty acids simulating the extract; responses were moderate to D. andersoni females treated with the same extract or fatty acid mixture. They also responded moderately to conspecific females treated with D. andersoni extract. Male D. andersoni displayed moderate increases in mating behavior over a range of concentrations of stearic and palmitic acids and conspecific ART extract. D. andersoni males mated only with D. andersoni females treated with a conspecific extract or a mixture of fatty acids simulating the extract. Mating by D. andersoni did not occur in response to D. variabilis females treated with D. andersoni or D. variabilis ART extracts. Stearic acid alone or in combination with 20-hydroxyecdysone, oleic, or myristic acid did not account for the specificity of response of either species. D. andersoni males were much less responsive to fatty acids, alone or in mixtures, than D. variabilis males. These findings indicate that fatty acids are important in mate recognition by D. variabilis, but explain only part of that by D. andersoni. The possibility is raised that another compound is required for mate recognition by D. andersoni.

Ticks and Tick-borne Diseases, Jul 1, 2015

Rickettsia parkeri, an obligate intracellular bacterium, is a member of the spotted fever group o... more Rickettsia parkeri, an obligate intracellular bacterium, is a member of the spotted fever group of rickettsiae (SFGR), and is transmitted to humans and other animals by invertebrate vectors. In the United States, the primary vector of R. parkeri is the Gulf Coast tick, Amblyomma maculatum Koch. This study investigates the vertical transmission dynamics of R. parkeri within a field-derived, naturally infected colony of A. maculatum. Transovarial and transstadial transmission of the pathogen was observed over three generations, with transovarial transmission efficiency averaging 83.7% and transstadial transmission rates approaching 100%. Fitness costs were determined by comparing reproduction values of the R. parkeri-infected A. maculatum colony to values from a R. parkeri-free colony. No significant reproductive fitness costs to the host ticks were detected in the R. parkeri-infected A. maculatum colony. Significantly fewer engorged F 1 nymphs and F 2 larvae of the R. parkeri-free colony succeeded in molting, suggesting that there may be some advantage to survival conferred by R. parkeri. The results of this study indicate that R. parkeri is maintained in A. maculatum populations efficiently by transovarial and transstadial transmission without any noticeable effects on tick reproduction or survival.

Insect Molecular Biology, 2011

454 Pyrosequencing was used to characterize the expressed genes from the synganglion and associat... more 454 Pyrosequencing was used to characterize the expressed genes from the synganglion and associated neurosecretory organs of unfed and partially fed virgin and mated replete females of the American dog tick, Dermacentor variabilis. A total of 14,881 contiguous sequences (contigs) was assembled, with an average size of 229 bp. Gene ontology terms for Level 2 biological processes were assigned to 4366 contigs. Seven acetylcholinesterases, a muscarinic acetylcholine (ACh) receptor, two nicotinic ACh receptor β-subunits, two ACh unc-18 regulators, two dopamine receptors, two gamma aminobutyric acid (GABA) receptors, two GABA transporters, two norepinephrine transporters and an octopamine receptor are described. Microarrays were conducted to examine global gene expression and quantitative real-time polymerase chain reaction was used to verify expression of selected neuropeptides. Hierarchical clustering of all differentially expressed transcripts grouped part-fed and replete ticks as being more similar in terms of differentially expressed genes with unfed ticks as the outgroup. Nine putative neuropeptides (allatostatin, bursicon-β, preprocorazonin, glycoprotein hormone α, insulin-like peptide, three orcokinins, preprosulphakinin) and a gonadotropin releasing hormone receptor were differentially expressed, and their developmental expression and role in reproduction was investigated. The presence of eclosion hormone, corazonin and bursicon in the synganglion, which in insects regulate behaviour and cuticle development associated with moulting, suggest that this system may be used in ticks to regulate blood feeding, cuticle expansion and development related to female reproduction; adult ticks do not moult.

Experimental and Applied Acarology, May 28, 2008

Defensins are an important component of the innate immune system of ticks. These small peptides a... more Defensins are an important component of the innate immune system of ticks. These small peptides are produced by various genera of tick, and expressed in various tissues. In this study we used RNA interference to silence the expression of the defensin varisin produced by the hemocytes of the American dog tick, Derrnacentor variabilis. Ticks were injected with double stranded varisin RNA. prior to being put on a rabbit. After feeding, the ticks were removed and bled. Hemolymph and hemocytes were separated and screened for the presence (or absence) of both varisin transcript and peptide. Varisin peptide was below detectable levels and the transcript showed a greater than 99% knockdown. The antimicrobial activity of the hemolymph plasma was reduced 2 to 4 fold compared to that of control injected ticks indicating varisin accounts for a large portion of the antimicrobial activity of the hemolymph.

Journal of Medical Entomology, 1990

Changes in DNA, RNA, total lipids, phospholipids, and proteins and the activity of certain enzyme... more Changes in DNA, RNA, total lipids, phospholipids, and proteins and the activity of certain enzymes and pattern of their isozymes were studied in Hyalomma dromedarii Koch during embryogenesis. Total proteins fluctuated with a net increase (P less than 0.05) on day 20. Total lipids increased during the first half of embryogenesis and then declined with a net decrease to about 60% of the original level. Total phospholipids decreased to half this original level. DNA content increased greatly during cleavage, gastrulation, and organogeny and RNA increased during cleavage and blastula formation. Glucose-6-phosphate dehydrogenase (G6PDH) activity decreased (P less than 0.05), reaching 20% of its original level on day 12. Malic acid dehydrogenase (MDH) activity remained nearly unchanged throughout embryogenesis. Lactic acid dehydrogenase (LDH) activity increased greatly, with the highest level on day 14 with no further change. Acetylcholinesterase (AchE) activity increased greatly during the first 12 d, with no significant change thereafter. Acid (ACP) and alkaline (ALP) phosphatase activity increased during the first 12 d and declined returning to the original level on day 20. Seven AchE and 5 LDH isozymes were detected during different embryogenesis stages. Two MDH, 2 ACP, 1 ALP, and 2 G6PDH isozymes were detected throughout embryogenesis. Treating the mother with 20-hydroxyecdysone was associated with increases in protein and RNA contents and G6PDH and AchE activity and with decreases in ACP and ALP activity in the embryos.

Insect Molecular Biology, 2008

VectorBase, an integrated, relational database that manages genomic and other genetic/biological ... more VectorBase, an integrated, relational database that manages genomic and other genetic/biological data pertaining to arthropod vectors of disease, has recently embarked on the construction of ontologies and controlled vocabularies (CVs). It aims, thus, at providing all necessary tools for the complete annotation of vector genomes and, in particular, the annotation of functional genomic data. This task was initiated with the development of anatomical ontologies of mosquitoes and ticks, both of which were made compliant to CARO, the common anatomy reference ontology. The ontologies are complemented by the development of novel web-based browsers that can show figures for anatomical terms, something that is especially helpful for fully illustrating the controlled vocabularies of anatomy.

Environmental Health Perspectives, 1986

The chemical reactions that hypochlorite undergoes in the body when chlorinated water is ingested... more The chemical reactions that hypochlorite undergoes in the body when chlorinated water is ingested have received very little attention. Because amino nitrogen compounds are important components of the average diet, the reactions of hypochlorite with amino compounds in the stomach were investigated. Stomach fluid was recovered from Sprague-Dawley rats that had been fasted for 48 hr and administered 4 mL deionized water. The chlorine demand of the stomach fluid was determined. An average volumeindependent demand of 2.7 mg chlorine was measured. At doses below 40 mg/L chlorine reducing reactions appeared to account for reduction of all oxidizing species within 15 min as measured by the FAS-DPD titrimetric method. At least part of the chlorine demand is associated with amino acids present in the stomach fluid. Amino acids were identified and quantified in the stomach fluid by precolumn derivatization with o-phthalaldehyde and high-pressure liquid chromatography (HPLC). When stomach fluid is chlorinated to concentrations of chlorine between 200 and 1000 mg/L, organic Nchloramines are formed. After derivatization of chlorinated stomach fluid with dansyl sulfinic acid, fluorescent derivatives of chloramines were separated by HPLC. Three chloramino acid derivatives, N-chloroalanine, N-chloroglycine, and N-chlorophenylalanine, were identified by cochromatography with known standards using two chromatographic methods. The yield of a chloramine that would form in stomach fluid on administration of hypochlorite to animals was determined using tritiated piperidine and doses of 200 and 1000 mg/L chlorine. Yields of tritiated Nchloropiperidine in recovered stomach fluid were 70%o and 42%, respectively, of the theoretical amount expected.