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Venom Ontogeny in the Mexican Lance-Headed Rattlesnake (Crotalus polystictus)

As trophic adaptations, rattlesnake venoms can vary in composition depending on several intrinsic and extrinsic factors. Ontogenetic changes in venom composition have been documented for numerous species, but little is known of the potential age-related changes in many rattlesnake species found in M...

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Autores principales: Mackessy, Stephen P., Leroy, Jamie, Mociño-Deloya, Estrella, Setser, Kirk, Bryson, Robert W., Saviola, Anthony J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6070973/
https://www.ncbi.nlm.nih.gov/pubmed/29970805
http://dx.doi.org/10.3390/toxins10070271
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author Mackessy, Stephen P.
Leroy, Jamie
Mociño-Deloya, Estrella
Setser, Kirk
Bryson, Robert W.
Saviola, Anthony J.
author_facet Mackessy, Stephen P.
Leroy, Jamie
Mociño-Deloya, Estrella
Setser, Kirk
Bryson, Robert W.
Saviola, Anthony J.
author_sort Mackessy, Stephen P.
collection PubMed
description As trophic adaptations, rattlesnake venoms can vary in composition depending on several intrinsic and extrinsic factors. Ontogenetic changes in venom composition have been documented for numerous species, but little is known of the potential age-related changes in many rattlesnake species found in México. In the current study, venom samples collected from adult and neonate Crotalus polystictus from Estado de México were subjected to enzymatic and electrophoretic analyses, toxicity assays (LD(50)), and MALDI-TOF mass spectrometry, and a pooled sample of adult venom was analyzed by shotgun proteomics. Electrophoretic profiles of adult males and females were quite similar, and only minor sex-based variation was noted. However, distinct differences were observed between venoms from adult females and their neonate offspring. Several prominent bands, including P-I and P-III snake venom metalloproteinases (SVMPs) and disintegrins (confirmed by MS/MS) were present in adult venoms and absent/greatly reduced in neonate venoms. Age-dependent differences in SVMP, kallikrein-like, phospholipase A(2) (PLA(2)), and L-amino acid oxidase (LAAO) activity levels were confirmed by enzymatic activity assays, and like many other rattlesnake species, venoms from adult snakes have higher SVMP activity than neonate venoms. Conversely, PLA(2) activity was approximately 2.5 × greater in venoms from neonates, likely contributing to the increased toxicity (neonate venom LD(50) = 4.5 μg/g) towards non-Swiss albino mice when compared to adult venoms (LD(50) = 5.5 μg/g). Thrombin-like (TLE) and phosphodiesterase activities did not vary significantly with age. A significant effect of sex (between adult male and adult female venoms) was also observed for SVMP, TLE, and LAAO activities. Analysis of pooled adult venom by LC-MS/MS identified 14 toxin protein families, dominated by bradykinin-inhibitory peptides, SVMPs (P-I, P-II and P-III), disintegrins, PLA(2)s, C-type-lectins, CRiSPs, serine proteinases, and LAAOs (96% of total venom proteins). Neonate and adult C. polystictus in this population consume almost exclusively mammals, suggesting that age-based differences in composition are related to physical differences in prey (e.g., surface-to-volume ratio differences) rather than taxonomic differences between prey. Venoms from adult C. polystictus fit a Type I pattern (high SVMP activity, lower toxicity), which is characteristic of many larger-bodied rattlesnakes of North America.
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spelling pubmed-60709732018-08-09 Venom Ontogeny in the Mexican Lance-Headed Rattlesnake (Crotalus polystictus) Mackessy, Stephen P. Leroy, Jamie Mociño-Deloya, Estrella Setser, Kirk Bryson, Robert W. Saviola, Anthony J. Toxins (Basel) Article As trophic adaptations, rattlesnake venoms can vary in composition depending on several intrinsic and extrinsic factors. Ontogenetic changes in venom composition have been documented for numerous species, but little is known of the potential age-related changes in many rattlesnake species found in México. In the current study, venom samples collected from adult and neonate Crotalus polystictus from Estado de México were subjected to enzymatic and electrophoretic analyses, toxicity assays (LD(50)), and MALDI-TOF mass spectrometry, and a pooled sample of adult venom was analyzed by shotgun proteomics. Electrophoretic profiles of adult males and females were quite similar, and only minor sex-based variation was noted. However, distinct differences were observed between venoms from adult females and their neonate offspring. Several prominent bands, including P-I and P-III snake venom metalloproteinases (SVMPs) and disintegrins (confirmed by MS/MS) were present in adult venoms and absent/greatly reduced in neonate venoms. Age-dependent differences in SVMP, kallikrein-like, phospholipase A(2) (PLA(2)), and L-amino acid oxidase (LAAO) activity levels were confirmed by enzymatic activity assays, and like many other rattlesnake species, venoms from adult snakes have higher SVMP activity than neonate venoms. Conversely, PLA(2) activity was approximately 2.5 × greater in venoms from neonates, likely contributing to the increased toxicity (neonate venom LD(50) = 4.5 μg/g) towards non-Swiss albino mice when compared to adult venoms (LD(50) = 5.5 μg/g). Thrombin-like (TLE) and phosphodiesterase activities did not vary significantly with age. A significant effect of sex (between adult male and adult female venoms) was also observed for SVMP, TLE, and LAAO activities. Analysis of pooled adult venom by LC-MS/MS identified 14 toxin protein families, dominated by bradykinin-inhibitory peptides, SVMPs (P-I, P-II and P-III), disintegrins, PLA(2)s, C-type-lectins, CRiSPs, serine proteinases, and LAAOs (96% of total venom proteins). Neonate and adult C. polystictus in this population consume almost exclusively mammals, suggesting that age-based differences in composition are related to physical differences in prey (e.g., surface-to-volume ratio differences) rather than taxonomic differences between prey. Venoms from adult C. polystictus fit a Type I pattern (high SVMP activity, lower toxicity), which is characteristic of many larger-bodied rattlesnakes of North America. MDPI 2018-07-03 /pmc/articles/PMC6070973/ /pubmed/29970805 http://dx.doi.org/10.3390/toxins10070271 Text en © 2018 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Mackessy, Stephen P.
Leroy, Jamie
Mociño-Deloya, Estrella
Setser, Kirk
Bryson, Robert W.
Saviola, Anthony J.
Venom Ontogeny in the Mexican Lance-Headed Rattlesnake (Crotalus polystictus)
title Venom Ontogeny in the Mexican Lance-Headed Rattlesnake (Crotalus polystictus)
title_full Venom Ontogeny in the Mexican Lance-Headed Rattlesnake (Crotalus polystictus)
title_fullStr Venom Ontogeny in the Mexican Lance-Headed Rattlesnake (Crotalus polystictus)
title_full_unstemmed Venom Ontogeny in the Mexican Lance-Headed Rattlesnake (Crotalus polystictus)
title_short Venom Ontogeny in the Mexican Lance-Headed Rattlesnake (Crotalus polystictus)
title_sort venom ontogeny in the mexican lance-headed rattlesnake (crotalus polystictus)
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6070973/
https://www.ncbi.nlm.nih.gov/pubmed/29970805
http://dx.doi.org/10.3390/toxins10070271
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