A developmental shift in venom toxin expression underpins a major prey switch in Australian Brown Snakes

Many animals change traits over the course of their lifetime, yet few clear examples exist of how thse trains enable ecological shifts within an animal's life. We demonstrate that a body size correlated dietary shift from small lizards to mammals in one of Australia's most venomous snake speices is accompanied by a major change in venom compostion. The timing of this prey shift coincides with the coordinated expression of multiple toxin genes, transforming the venom from a neurotoxic phenotype in lizard feeding juveniles to a potent procoagulant phenotype in mammal feeding adults.

诸多动物在生命周期中会发生性状改变，但目前鲜有清晰案例可阐明此类性状如何在动物个体生命周期内推动生态位转变。本研究证实，澳大利亚毒性最强的蛇类之一，其体型相关的食性转变（从小型蜥蜴转向哺乳类）会伴随毒液组分的显著改变。该食性转变的时间节点与多种毒素基因的协同表达高度吻合，使得毒液发生表型转换：以蜥蜴为食的幼蛇毒液呈神经毒性表型，而以哺乳类为食的成体毒液则转变为强效促凝血表型。