Experimental Manipulation of Corticosterone Does Not Affect Venom Composition or Functional Activity in Free-Ranging Rattlesnakes
Experimental Manipulation of Corticosterone Does Not Affect Venom Composition or Functional Activity in Free-Ranging Rattlesnakes
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DOI：
10.1086/714936
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发表时间：
2021-09-01
影响因子：
1.6
通讯作者：
Taylor，Emily N.
中科院分区：
文献类型：
--
作者：
Claunch，Natalie M.;Holding，Matthew;Taylor，Emily N.
毒液是许多动物物种不可或缺的摄食特性。尽管毒液经常在个体发生上发生变化，但人们对个体内毒液变异的直接生理介质知之甚少。糖皮质激素皮质酮 (CORT) 可以改变蛋白质的转录和激活，包括蛇毒金属蛋白酶 (SVMP) 和磷脂酶 A2 (PLA2) 等蛇毒成分的同源物。 CORT 是蛇内源性产生的，随季节变化以及对压力的反应而变化，是毒液成分和功能活动变化的候选内源性调节剂。在这里，我们通过对野生成年响尾蛇在用空的（对照）或充满 CORT 的（治疗）硅橡胶植入物治疗前后的毒液进行采样，测试了 CORT 诱导蛇毒变化的假设。我们测量了全毒液成分、全毒液总蛋白含量以及毒液 SVMP 和 PLA2 成分的酶活性的纵向变化。我们还评估了毒液成分的个体内可重复性。尽管治疗组成功提高了血浆 CORT，但我们发现 CORT 治疗或平均血浆 CORT 水平对任何测量的毒液变量没有影响。除总蛋白质含量外，毒液成分在个体内具有高度可重复性（）。我们的研究结果表明，CORT（一种通常与压力和代谢功能相关的激素）在成年响尾蛇毒液中的影响可以忽略不计。我们的研究结果对于毒液研究人员和生物医学应用来说是个好兆头，这些应用依赖于潜在压力个体产生的毒液的一致性，并为未来研究个体一生中毒液变异的直接介质提供了一个实验框架。
Venom is an integral feeding trait in many animal species. Although venom often varies ontogenetically, little is known about the proximate physiological mediators of venom variation within individuals. The glucocorticoid hormone corticosterone (CORT) can alter the transcription and activation of proteins, including homologues of snake venom components such as snake venom metalloproteinases (SVMPs) and phospholipase A2(PLA2). CORT is endogenously produced by snakes, varies seasonally and also in response to stress, and is a candidate endogenous mediator of changes in venom composition and functional activity. Here, we tested the hypothesis that CORT induces changes in snake venom by sampling the venom of wild adult rattlesnakes before and after they were treated with either empty (control) or CORT-filled (treatment) Silastic implants. We measured longitudinal changes in whole-venom composition, whole-venom total protein content, and enzymatic activity of SVMP and PLA2components of venom. We also assessed the within-individual repeatability of venom components. Despite successfully elevating plasma CORT in the treatment group, we found no effect of CORT treatment or average plasma CORT level on any venom variables measured. Except for total protein content, venom components were highly repeatable within individuals (). Our results indicate that the effects of CORT, a hormone commonly associated with stress and metabolic functions, in adult rattlesnake venom are negligible. Our findings bode well for venom researchers and biomedical applications that rely on the consistency of venoms produced from potentially stressed individuals and provide an experimental framework for future studies of proximate mediators of venom variation across an individual’s life span.