An isoelectric focusing study of seasonal variation in rattlesnake venom proteins

Comparison of venoms from wild and long-term captive Bothrops atrox snakes and characterization of Batroxrhagin, the predominant class PIII metalloproteinase from the venom of this species

“…The variation in the composition of venoms after introducing the snakes to controlled environment was analyzed by Gregory-Dwyer and collaborators [47]. The authors compared three species of Crotalus housed under the same temperature and light conditions and fed on the same diet for 20 months; they observed little changes in the eletrofocusing patterns of the venoms, suggesting that interspecific variation is genetically inherited instead of experimentally induced.…”

Proteomic analysis of ontogenetic and diet-related changes in venom composition of juvenile and adult Dusky Pigmy rattlesnakes (Sistrurus miliarius barbouri)

“…For example, Gregory-Dwyer et al [7] found little change in the in isoelectric focusing patterns of venom of adult specimens of C. viridis helleri, C. molossus molossus, and C. atrox housed under controlled light and temperature to simulate seasonal change, fed on the same diet, and milked monthly over a 20 month period. This evidence suggested that intraspecific variation is genetically inherited rather than environmentally induced.…”

“…Analysis of snake venom proteins (SVPs) using protein gel electrophoresis has consistently shown high levels of intra-and interspecific variation (for review see [3]) and there are a small but increasing number of studies that strongly support the idea that this variation reflects local adaptation for feeding on different prey [4]. There is indirect evidence that at some of this variation is under genetic control [5][6][7][8] possibly as a result of amino-acid altering substitutions in venom genes [9][10][11] or the presence or absence of alleles that code for specific venom proteins [12]. However, there is also evidence that individual venom composition can be plastic through time likely due to the effects of gene regulation.…”

Stress Ecology of the Pacific Rattlesnakes (Crotalus Oreganus and Crotalus Helleri)

“…We used newer techniques to revisit the conclusion of Gregory-Dwyer et al (1986) that venom may not be a plastic trait in adult rattlesnakes. These authors used gel isoelectric focusing techniques to investigate plasticity of venom composition in multiple species of captive rattlesnakes exposed to seasonal fluctuations in light and temperature, with no changes observed within individuals.…”

“…In captive rattlesnakes, seasonal changes in temperature or photoperiod did not alter venom composition measured through 1D gel banding patterns (Dwyer et al 1986). To the contrary, two bands disappeared completely from pooled samples of sand vipers (Vipera ammodytes) during the summer (Gubensek et al, 1974), and monthly venom extraction of a single Eastern Brown Snake (Pseudonaja textilis) yielded trends in venom enzymatic activity that suggest seasonal upregulation of certain enzyme classes (Williams,1992).…”