Observations on the chemosensory responses of the midget faded rattlesnake (Crotalus oreganus concolor): discrimination of envenomated prey in a type II venom species

Saviola, Anthony J.; Mackessy, Stephen P.

doi:10.1007/s10164-017-0511-2

Cited by 2 publications

(1 citation statement)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The concentration of disintegrin required for successful prey recovery remains unknown. However, in C. o. concolor , which exhibits a type II venom phenotype [ 24 ] and has significantly less disintegrin compared to type I species such as C. atrox , C. o. oreganus/helleri and C. polystictus , successful discrimination between envenomated and non-envenomated prey cues has been documented [ 47 ].…”

Section: Discussionmentioning

confidence: 99%

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

Mackessy

Leroy

Mociño-Deloya

et al. 2018

Toxins

View full text Add to dashboard Cite

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 (LD50), 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 A2 (PLA2), 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, PLA2 activity was approximately 2.5 × greater in venoms from neonates, likely contributing to the increased toxicity (neonate venom LD50 = 4.5 μg/g) towards non-Swiss albino mice when compared to adult venoms (LD50 = 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, PLA2s, 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.

show abstract

Section: Discussionmentioning

confidence: 99%