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Terence M Farrell - One of the best experts on this subject based on the ideXlab platform.
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the metabolic response to an immune challenge in a viviparous snake Sistrurus miliarius
The Journal of Experimental Biology, 2020Co-Authors: Craig M Lind, Joseph Agugliaro, Terence M FarrellAbstract:Mounting an immune response may be energetically costly and require the diversion of resources away from other physiological processes. Yet, both the metabolic cost of immune responses and the factors that impact investment priorities remain poorly described in many vertebrate groups. For example, although viviparity has evolved many times in vertebrates, the relationship between immune function and pregnancy has been disproportionately studied in placental mammals. To examine the energetic costs of immune activation and the modulation of immune function during pregnancy in a non-mammalian vertebrate, we elicited an immune response in pregnant and non-pregnant pygmy rattlesnakes, Sistrurus miliarius, using lipopolysaccharide (LPS). Resting metabolic rate (RMR) was measured using flow-through respirometry. Immune function was examined using bactericidal assays and leukocyte counts. The RMR of pygmy rattlesnakes increased significantly in response to LPS injection. There was no statistically significant difference in the metabolic response of non-reproductive and pregnant snakes to LPS. Mean metabolic increments for pregnant females, non-reproductive females, and males were 13%, 18%, and 26%, respectively. The ratio of heterophils to lymphocytes was elevated in response to LPS across reproductive categories; however, LPS did not impact plasma bactericidal ability in non-reproductive snakes. Although pregnant females had significantly higher plasma bactericidal ability compared to non-reproductive snakes prior to manipulation, their bactericidal ability declined in response to LPS. LPS administration also significantly reduced several litter characteristics, particularly when administrated relatively early in pregnancy. Our results indicate that immune performance is energetically costly, altered during pregnancy, and that immune activation during pregnancy may result in tradeoffs that affect offspring in a viviparous reptile.
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seasonal testosterone and corticosterone patterns in relation to body condition and reproduction in a subtropical pitviper Sistrurus miliarius
General and Comparative Endocrinology, 2018Co-Authors: Craig M Lind, Ignacio T Moore, Ben J Vernasco, Terence M FarrellAbstract:Abstract Seasonal constraints on the timing and intensity of reproductive events shape observed variation in life history strategies across latitudes. Selection acts on the endocrine mechanisms that underlie reproductive investment. It is therefore important to examine the seasonal relationship between hormones and reproduction in geographically and phylogenetically diverse taxa. Snakes have proven to be a valuable model in investigations of seasonal hormone production and behavior in field-active vertebrates, but most research has focused on temperate populations from highly seasonal environments. To reduce this bias, we provide a description of the seasonal relationships among testosterone, corticosterone, body condition, and reproductive behavior in a subtropical population of Pygmy Rattlesnakes, Sistrurus miliarius. In central Florida, Sistrurus miliarius exhibits a prolonged breeding season (September-January) compared to most temperate zone snakes. Despite the extended breeding season, the pattern of testosterone in the population was highly seasonal and very similar to temperate pitvipers with a shorter mating season. Testosterone declined steadily through the mating season, but males sampled while engaging in mating behaviors had higher testosterone compared to solitary males throughout the mating season. Testosterone was negatively related to corticosterone throughout the breeding season and during times of year when the gonads were presumed to be quiescent and no mating behavior was observed. Testosterone was positively related to individual body condition both within and outside of the breeding season. A review of the literature reveals no consistent pattern regarding the relationship between corticosterone and testosterone in snakes, but suggests that the condition-dependence of steroid production may be consistent across snake taxa.
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prey species influences foraging behaviors rattlesnake Sistrurus miliarius predation on little brown skinks scincella lateralis and giant centipedes scolopendra viridis
Journal of Herpetology, 2018Co-Authors: Terence M Farrell, Sarah A Smileywalters, Diane E MccollAbstract:Abstract Predators often evolve specialized behaviors to feed on dangerous prey. Centipedes are widely documented in the diet of viperid snakes, but the behaviors snakes use to consume these dangerous prey have been reported only anecdotally. To determine how prey type influenced snake foraging behaviors, we ran laboratory predation trials using 29 field-captured Pigmy Rattlesnakes (Sistrurus miliarius) with centipedes (Scolopendra viridis) and skinks (Scincella lateralis). In skink trials, Pigmy Rattlesnakes were significantly more likely to engage in sit-and-wait predation than in centipede trials where active pursuit of prey was frequent. Centipedes were struck by snakes in significantly more trials than skinks and the mean length of strikes directed at centipedes was significantly shorter than for the strikes directed at skinks. Strike latency was significantly lower for centipedes than for skinks. The location on the prey's body where the strike was directed did not differ in skink and centipede tria...
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tracking outcomes of snake fungal disease in free ranging pygmy rattlesnakes Sistrurus miliarius
Journal of Wildlife Diseases, 2018Co-Authors: Craig M Lind, Ciera M Mccoy, Terence M FarrellAbstract:Abstract: Snake fungal disease (SFD) is caused by the fungus Ophidiomyces ophiodiicola and its documentation in wild snake populations has risen sharply in the past decade. Little is known regarding the fate of individual, free-ranging snakes afflicted with SFD. We monitored an afflicted population of pygmy rattlesnakes (Sistrurus miliarius) at Lake Woodruff National Wildlife Refuge in Central Florida, US for 2 yr. The severity of SFD in individual snakes was unrelated to the probability of their recapture later in the study, and half of the snakes diagnosed as severely infected at the onset of the study were recaptured later with no clinical signs of SFD. The clinical progress of 12 serially recaptured individuals also showed that individuals cleared the infection and fluctuated between no or low and severe clinical signs over the 2-yr study.
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Evaluating local adaptation of a complex phenotype: reciprocal tests of pigmy rattlesnake venoms on treefrog prey
Oecologia, 2017Co-Authors: Sarah A. Smiley-walters, Terence M Farrell, H. Lisle GibbsAbstract:Theory predicts that predator–prey interactions can generate reciprocal selection pressures on species pairs, which can result in local adaptation, yet the presence and pattern of local adaptation is poorly studied in vertebrate predator–prey systems. Here, we used a reciprocal common garden (laboratory) experimental design involving comparisons between local and foreign populations to determine if local adaptation was present between a generalist predator—the pigmy rattlesnake ( Sistrurus miliarius )—and a co-occurring prey—the squirrel treefrog ( Hyla squirella ). We conducted toxicity trials using snake venom from two populations separated by 340 km tested on prey from sympatric and allopatric populations, resulting in data from four venom origin–frog origin combinations. We assessed venom effectiveness using two measures (frog mortality at 24 h and time to frog death) and then used regression analyses to look for a signal of local adaptation with either measure. We found evidence for local adaptation for one measure (time to death), but not the other (frog mortality). We argue that in this system, the time to death of a prey item is a more ecologically relevant measure of venom effectiveness than is frog mortality at 24 h. Our results document an example of local adaptation between two interacting vertebrates using a whole-organism assay and a local versus foreign criteria and provide evidence that population-level variation in snake venom is adaptive.
Gabriela F. Mastromonaco - One of the best experts on this subject based on the ideXlab platform.
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validation of a shed skin corticosterone enzyme immunoassay in the african house snake lamprophis fuliginosus and its evaluation in the eastern massasauga rattlesnake Sistrurus catenatus catenatus
General and Comparative Endocrinology, 2013Co-Authors: Charlene N. Berkvens, Christine Gilman, Crystal Hyatt, David L Pearl, Ian K Barker, Gabriela F. MastromonacoAbstract:Abstract This study investigates the use of an enzyme immunoassay to measure keratin glucocorticoid concentrations in reptilian shed skins. Keratin glucocorticoid concentrations were compared to fecal glucocorticoid concentrations during the period of keratin growth in the African House Snake ( Lamprophis fuliginosus ) and the Eastern Massasauga Rattlesnake ( Sistrurus catenatus catenatus ). Biochemical validation was performed for the shed skin and fecal corticosterone enzyme immunoassays in the African House Snake. Biological and physiological validations were attempted in the African House Snake. A statistically significant positive association was detected between shed skin corticosterone and the mean fecal corticosterone metabolites from 3 weeks before to 1 week after the previous ecdysis in the African House Snake. A statistically significant difference was not detected between the shed skin corticosterone concentrations of the minimally handled control and the weekly handled (or experimentally stressed) African House Snakes. Adrenocorticotropic hormone stimulation did not result in the physiological validation anticipated for shed skin corticosterone concentrations in the African House Snake.
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Validation of a shed skin corticosterone enzyme immunoassay in the African House Snake (Lamprophis fuliginosus) and its evaluation in the Eastern Massasauga Rattlesnake (Sistrurus catenatus catenatus)
General and Comparative Endocrinology, 2013Co-Authors: Charlene N. Berkvens, Christine Gilman, Crystal Hyatt, David L Pearl, Ian K Barker, Gabriela F. MastromonacoAbstract:This study investigates the use of an enzyme immunoassay to measure keratin glucocorticoid concentrations in reptilian shed skins. Keratin glucocorticoid concentrations were compared to fecal glucocorticoid concentrations during the period of keratin growth in the African House Snake (Lamprophis fuliginosus) and the Eastern Massasauga Rattlesnake (Sistrurus catenatus catenatus). Biochemical validation was performed for the shed skin and fecal corticosterone enzyme immunoassays in the African House Snake. Biological and physiological validations were attempted in the African House Snake. A statistically significant positive association was detected between shed skin corticosterone and the mean fecal corticosterone metabolites from 3. weeks before to 1. week after the previous ecdysis in the African House Snake. A statistically significant difference was not detected between the shed skin corticosterone concentrations of the minimally handled control and the weekly handled (or experimentally stressed) African House Snakes. Adrenocorticotropic hormone stimulation did not result in the physiological validation anticipated for shed skin corticosterone concentrations in the African House Snake. © 2013 Elsevier Inc.
Stephen P Mackessy - One of the best experts on this subject based on the ideXlab platform.
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desert massasauga rattlesnakes Sistrurus catenatus edwardsii in southeastern colorado life history reproduction and communal hibernation
Journal of Herpetology, 2016Co-Authors: Andrew R Wastell, Stephen P MackessyAbstract:Abstract We studied Desert Massasauga Rattlesnakes (Sistrurus catenatus edwardsii) in southeastern Colorado in 1998 and 2005–2007. Mark–recapture data for 770 snakes indicated a population size of >3,500 snakes in an area of approximately 4,800 ha. Field growth rates and size class frequency distributions showed that average snake age was 3 yr; 4 yr old snakes were frequently encountered, but less than 4% were 5 yr or older, suggesting low survivorship beyond this age. Conversely, initial growth was rapid; snakes grew an average of 0.57 mm/day in their first full year. Desert Massasaugas mated in fall and spring, producing 2–7 (mean 3.3) young in late August to early September, and reproduction appeared to be biennial. Desert Massasaugas showed maternal attendance for at least 5 days postparturition, and neonate dispersal corresponded with the first shed. Radioed Desert Massasaugas (N = 15) used rodent burrows as hibernacula, and within 50 m of Desert Massasauga hibernacula, eight snake, five anuran, and ...
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interrogating the venom of the viperid snake Sistrurus catenatus edwardsii by a combined approach of electrospray and maldi mass spectrometry
PLOS ONE, 2015Co-Authors: Stephen P Mackessy, Alex Chapeaurouge, Abu Reza, Paulo C Carvalho, Richard H Valente, Andre Teixeiraferreira, Jonas Perales, Manjunatha R KiniAbstract:The complete sequence characterization of snake venom proteins by mass spectrometry is rather challenging due to the presence of multiple isoforms from different protein families. In the present study, we investigated the tryptic digest of the venom of the viperid snake Sistrurus catenatus edwardsii by a combined approach of liquid chromatography coupled to either electrospray (online) or MALDI (offline) mass spectrometry. These different ionization techniques proved to be complementary allowing the identification a great variety of isoforms of diverse snake venom protein families, as evidenced by the detection of the corresponding unique peptides. For example, ten out of eleven predicted isoforms of serine proteinases of the venom of S. c. edwardsii were distinguished using this approach. Moreover, snake venom protein families not encountered in a previous transcriptome study of the venom gland of this snake were identified. In essence, our results support the notion that complementary ionization techniques of mass spectrometry allow for the detection of even subtle sequence differences of snake venom proteins, which is fundamental for future structure-function relationship and possible drug design studies.
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spatial ecology and factors influencing movement patterns of desert massasauga rattlesnakes Sistrurus catenatus edwardsii i n southeastern colorado
Copeia, 2011Co-Authors: Andrew R Wastell, Stephen P MackessyAbstract:The Massasauga Rattlesnake (Sistrurus catenatus) occurs from extreme southeastern Canada to northern Mexico, and most populations are highly threatened due to habitat loss and fragmentation. Although their range is reduced from historical levels, they may be locally abundant in appropriate habitat. We studied movement patterns, home range and core activity centers, habitat use, and prey abundance in a robust population of Desert Massasauga Rattlesnakes (S. c. edwardsii) in southeastern Colorado by radiotracking 36 snakes over four active seasons (May–October). In the spring, snakes made long-distance directed movements (mean = 1.89 km) from the hibernacula (shortgrass, compacted clay soils) to summer foraging areas (mixed-grass/Sand Sagebrush, sandhills). Summer activity was characterized by short distance non-directional movements, and snakes were most often observed at the base of Sand Sagebrush (Artemisia filifolia). Home ranges and core activity centers were significantly larger for males than for females, but daily movements, total distance moved, and range length did not differ significantly between sexes. Prey base surveys indicated a significantly higher abundance of both rodents and lizards in summer foraging grounds than at hibernation sites. Snakes returned to the hibernaculum area in October and appeared to hibernate individually in rodent burrows. Migration patterns exhibited by S. c. edwardsii are likely resource driven, with the migratory movements observed in the spring resulting in utilization of summer foraging habitat with more abundant prey. Conversely, hibernacula with greater thermal and structural stability in the shortgrass habitat (perhaps due to the compacted clay soils versus loose sandy soils) favor migratory return for torpor in the fall. At present, the main populations in Colorado occur far from developing regions in the state, but due to habitat loss and fragmentation resulting from projected agricultural expansion and urbanization, these populations may be threatened in the future.
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spatial ecology and factors influencing movement patterns of desert massasauga rattlesnakes Sistrurus catenatus edwardsii in
2011Co-Authors: Andrew R Wastell, Stephen P MackessyAbstract:The Massasauga Rattlesnake {Sistrurus catenatus) occurs from extreme southeastern Canada to northern Mexico, and most populations are highly threatened due to habitat loss and fragmentation. Although their range is reduced from historical levels, they may be locally abundant in appropriate habitat. We studied movement patterns, home range and core activity centers, habitat use, and prey abundance in a robust population of Desert Massasauga Rattlesnakes (5. с edwardsii) in southeastern Colorado by radiotracking 36 snakes over four active seasons (May-October). In the spring, snakes made long-distance directed movements (mean = 1 .89 km) from the hibernacula (shortgrass, compacted clay soils) to summer foraging areas (mixed-grass/Sand Sagebrush, sandhills). Summer activity was characterized by short distance non-directional movements, and snakes were most often observed at the base of Sand Sagebrush (Artemisia fili folia). Home ranges and core activity centers were significantly larger for males than for females, but daily movements, total distance moved, and range length did not differ significantly between sexes. Prey base surveys indicated a significantly higher abundance of both rodents and lizards in summer foraging grounds than at hibernation sites. Snakes returned to the hibernaculum area in October and appeared to hibernate individually in rodent burrows. Migration patterns exhibited by 5. с edwardsii are likely resource driven, with the migratory movements observed in the spring resulting in utilization of summer foraging habitat with more abundant prey. Conversely, hibernacula with greater thermal and structural stability in the shortgrass habitat (perhaps due to the compacted clay soils versus loose sandy soils) favor migratory return for torpor in the fall. At present, the main populations in Colorado occur far from developing regions in the state, but due to habitat loss and fragmentation resulting from projected agricultural expansion and urbanization, these populations may be threatened in the future. elucidation of movement patterns and their relation to resource and habitat utilization data can
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the gene structure and evolution of ku wap fusin kunitz waprin fusion protein a novel evolutionary intermediate of the kunitz serine protease inhibitors and waprins from Sistrurus catenatus massasauga rattlesnake venom glands
The Open Evolution Journal, 2010Co-Authors: Robin Doley, Stephen P Mackessy, Abu Reza, Susanta Pahari, Manjunatha R KiniAbstract:Snake venom proteins belong to various families which differ in their primary and secondary structures. Re- cently, we found a novel transcript in the venom gland of Sistrurus catenatus edwardsii which was named "Ku-wap- fusin" because it encodes Kunitz-type serine protease inhibitors (Kunitz SPIs) and whey acidic protein (WAP) domains in tandem. We have now determined the gene structure of this unique transcript (from S. c. edwardsii and S. c. tergeminus) and analyzed its evolutionary relationships with genes encoding Kunitz-type serine protease inhibitors and waprins. Struc- turally, Ku-wap-fusin has four exons and three introns. Comparison of all gene structures (Kunitz SPI, WAP and fusin) shows that exon I in all of these genes is highly conserved and codes for the signal peptide. However, in the Ku-wap-fusin gene, there is an insertion of an exon, which codes for the WAP domain, in the intron II region of the Kunitz SPI gene. In the waprin gene, the exon II, encoding the Kunitz domain, has been lost. Ku-wap-fusin and waprin (whey acidic protein related proteins) genes therefore appear to have evolved via insertion/deletion of an exon. We propose a model for the evolution of these genes (using their gene structures) in which Kunitz, Ku-wap-fusin and waprin genes have evolved from a common ancestor. During the evolution of this protein family complex, the Ku-wap-fusin gene is likely an intermediate between the ancestral and the waprin genes.
Manjunatha R Kini - One of the best experts on this subject based on the ideXlab platform.
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interrogating the venom of the viperid snake Sistrurus catenatus edwardsii by a combined approach of electrospray and maldi mass spectrometry
PLOS ONE, 2015Co-Authors: Stephen P Mackessy, Alex Chapeaurouge, Abu Reza, Paulo C Carvalho, Richard H Valente, Andre Teixeiraferreira, Jonas Perales, Manjunatha R KiniAbstract:The complete sequence characterization of snake venom proteins by mass spectrometry is rather challenging due to the presence of multiple isoforms from different protein families. In the present study, we investigated the tryptic digest of the venom of the viperid snake Sistrurus catenatus edwardsii by a combined approach of liquid chromatography coupled to either electrospray (online) or MALDI (offline) mass spectrometry. These different ionization techniques proved to be complementary allowing the identification a great variety of isoforms of diverse snake venom protein families, as evidenced by the detection of the corresponding unique peptides. For example, ten out of eleven predicted isoforms of serine proteinases of the venom of S. c. edwardsii were distinguished using this approach. Moreover, snake venom protein families not encountered in a previous transcriptome study of the venom gland of this snake were identified. In essence, our results support the notion that complementary ionization techniques of mass spectrometry allow for the detection of even subtle sequence differences of snake venom proteins, which is fundamental for future structure-function relationship and possible drug design studies.
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the gene structure and evolution of ku wap fusin kunitz waprin fusion protein a novel evolutionary intermediate of the kunitz serine protease inhibitors and waprins from Sistrurus catenatus massasauga rattlesnake venom glands
The Open Evolution Journal, 2010Co-Authors: Robin Doley, Stephen P Mackessy, Abu Reza, Susanta Pahari, Manjunatha R KiniAbstract:Snake venom proteins belong to various families which differ in their primary and secondary structures. Re- cently, we found a novel transcript in the venom gland of Sistrurus catenatus edwardsii which was named "Ku-wap- fusin" because it encodes Kunitz-type serine protease inhibitors (Kunitz SPIs) and whey acidic protein (WAP) domains in tandem. We have now determined the gene structure of this unique transcript (from S. c. edwardsii and S. c. tergeminus) and analyzed its evolutionary relationships with genes encoding Kunitz-type serine protease inhibitors and waprins. Struc- turally, Ku-wap-fusin has four exons and three introns. Comparison of all gene structures (Kunitz SPI, WAP and fusin) shows that exon I in all of these genes is highly conserved and codes for the signal peptide. However, in the Ku-wap-fusin gene, there is an insertion of an exon, which codes for the WAP domain, in the intron II region of the Kunitz SPI gene. In the waprin gene, the exon II, encoding the Kunitz domain, has been lost. Ku-wap-fusin and waprin (whey acidic protein related proteins) genes therefore appear to have evolved via insertion/deletion of an exon. We propose a model for the evolution of these genes (using their gene structures) in which Kunitz, Ku-wap-fusin and waprin genes have evolved from a common ancestor. During the evolution of this protein family complex, the Ku-wap-fusin gene is likely an intermediate between the ancestral and the waprin genes.
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accelerated exchange of exon segments in viperid three finger toxin genes Sistrurus catenatus edwardsii desert massasauga
BMC Evolutionary Biology, 2008Co-Authors: Robin Doley, Stephen P Mackessy, Manjunatha R Kini, Susanta PahariAbstract:Background Snake venoms consist primarily of proteins and peptides showing a myriad of potent biological activities which have been shaped by both adaptive and neutral selective forces. Venom proteins are encoded by multigene families that have evolved through a process of gene duplication followed by accelerated evolution in the protein coding region.
Charlene N. Berkvens - One of the best experts on this subject based on the ideXlab platform.
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validation of a shed skin corticosterone enzyme immunoassay in the african house snake lamprophis fuliginosus and its evaluation in the eastern massasauga rattlesnake Sistrurus catenatus catenatus
General and Comparative Endocrinology, 2013Co-Authors: Charlene N. Berkvens, Christine Gilman, Crystal Hyatt, David L Pearl, Ian K Barker, Gabriela F. MastromonacoAbstract:Abstract This study investigates the use of an enzyme immunoassay to measure keratin glucocorticoid concentrations in reptilian shed skins. Keratin glucocorticoid concentrations were compared to fecal glucocorticoid concentrations during the period of keratin growth in the African House Snake ( Lamprophis fuliginosus ) and the Eastern Massasauga Rattlesnake ( Sistrurus catenatus catenatus ). Biochemical validation was performed for the shed skin and fecal corticosterone enzyme immunoassays in the African House Snake. Biological and physiological validations were attempted in the African House Snake. A statistically significant positive association was detected between shed skin corticosterone and the mean fecal corticosterone metabolites from 3 weeks before to 1 week after the previous ecdysis in the African House Snake. A statistically significant difference was not detected between the shed skin corticosterone concentrations of the minimally handled control and the weekly handled (or experimentally stressed) African House Snakes. Adrenocorticotropic hormone stimulation did not result in the physiological validation anticipated for shed skin corticosterone concentrations in the African House Snake.
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Validation of a shed skin corticosterone enzyme immunoassay in the African House Snake (Lamprophis fuliginosus) and its evaluation in the Eastern Massasauga Rattlesnake (Sistrurus catenatus catenatus)
General and Comparative Endocrinology, 2013Co-Authors: Charlene N. Berkvens, Christine Gilman, Crystal Hyatt, David L Pearl, Ian K Barker, Gabriela F. MastromonacoAbstract:This study investigates the use of an enzyme immunoassay to measure keratin glucocorticoid concentrations in reptilian shed skins. Keratin glucocorticoid concentrations were compared to fecal glucocorticoid concentrations during the period of keratin growth in the African House Snake (Lamprophis fuliginosus) and the Eastern Massasauga Rattlesnake (Sistrurus catenatus catenatus). Biochemical validation was performed for the shed skin and fecal corticosterone enzyme immunoassays in the African House Snake. Biological and physiological validations were attempted in the African House Snake. A statistically significant positive association was detected between shed skin corticosterone and the mean fecal corticosterone metabolites from 3. weeks before to 1. week after the previous ecdysis in the African House Snake. A statistically significant difference was not detected between the shed skin corticosterone concentrations of the minimally handled control and the weekly handled (or experimentally stressed) African House Snakes. Adrenocorticotropic hormone stimulation did not result in the physiological validation anticipated for shed skin corticosterone concentrations in the African House Snake. © 2013 Elsevier Inc.