Venom complexity of Bothrops atrox (common lancehead) siblings

Abstract Background: Variability in snake venoms is a well-studied phenomenon. However, sex-based variation of Bothrops atrox snake venom using siblings is poorly investigated. Bothrops atrox is responsible for the majority of snakebite accidents in the Brazilian Amazon region. Differences in the venom composition of Bothrops genus have been linked to several factors such as ontogeny, geographical distribution, prey preferences and sex. Thus, in the current study, venom samples of Bothrops atrox male and female siblings were analyzed in order to compare their biochemical and biological characteristics. Methods: Venoms were collected from five females and four males born from a snake captured from the wild in São Bento (Maranhão, Brazil), and kept in the Laboratory of Herpetology of Butantan Intitute. The venoms were analyzed individually and as a pool of each gender. The assays consisted in protein quantification, 1-DE, mass spectrometry, proteolytic, phospholipase A2, L-amino acid oxidase activities, minimum coagulant dose upon plasma, minimum hemorrhagic dose and lethal dose 50%. Results: Electrophoretic profiles of male’s and female’s venom pools were quite similar, with minor sex-based variation. Male venom showed higher LAAO, PLA2 and hemorrhagic activities, while female venom showed higher coagulant activity. On the other hand, the proteolytic activities did not show statistical differences between pools, although some individual variations were observed. Meanwhile, proteomic profile revealed 112 different protein compounds; of which 105 were common proteins of female’s and male’s venom pools and seven were unique to females. Despite individual variations, lethality of both pools showed similar values. Conclusion: Although differences between female and male venoms were observed, our results show that individual variations are significant even between siblings, highlighting that biological activities of venoms and its composition are influenced by other factors beyond gender.

摘要
背景：蛇毒的变异性是一个已被广泛研究的现象。然而，关于 Bothrops atrox 蛇毒在性别上的变异性，特别是利用同窝蛇进行比较的研究却相对匮乏。Bothrops atrox 是巴西亚马逊地区蛇咬伤事故的主要原因。Bothrops 属蛇毒成分的差异与多种因素有关，如个体发育、地理分布、猎物偏好和性别。因此，在本研究中，对从巴西马拉尼昂州桑本托（São Bento）野外捕获的蛇所产五只雌性和四只雄性同窝蛇的蛇毒样本进行了分析，以比较它们的生化特征和生物学特性。方法：从捕获于桑本托的蛇所产雌蛇五只和雄蛇四只中收集蛇毒，并保存在巴西坦坦生物研究所的爬虫学实验室中。蛇毒分别进行分析，并按性别进行混合。实验包括蛋白质定量、一维电泳、质谱分析、蛋白酶解、磷脂酶 A2、L-氨基酸氧化酶活性、血浆中的最小凝固剂量、最小出血剂量和致死剂量 50%。结果：雄性和雌性蛇毒混合物的电泳谱图非常相似，存在微小的性别差异。雄性蛇毒表现出更高的 L-氨基酸氧化酶、磷脂酶 A2 和出血活性，而雌性蛇毒则表现出更高的凝固活性。另一方面，蛋白酶解活性在混合物之间没有显示出统计学差异，尽管观察到一些个体差异。同时，蛋白质组学分析揭示了 112 种不同的蛋白质化合物；其中 105 种是雌性和雄性蛇毒混合物的共有蛋白质，七种仅存在于雌性蛇毒中。尽管存在个体差异，但两种混合物的致死性显示出相似的价值。结论：尽管观察到雌性和雄性蛇毒之间存在差异，但我们的研究结果证明，即使在同窝蛇之间，个体差异也十分显著，这突显了蛇毒的生物活性和其成分受到性别以外的其他因素的影响。