Phylogenetic analyses suggest centipede venom arsenals were repeatedly stocked by horizontal gene transfer

Venoms have evolved over a hundred times in animals. Venom toxins are thought to evolve mostly by recruitment of endogenous proteins with physiological functions. Here we report phylogenetic analyses of venom proteome-annotated venom gland transcriptome data, assisted by genomic analyses, to show that centipede venoms have recruited at least five gene families from bacterial and fungal donors, involving at least eight horizontal gene transfer events. These results establish centipedes as currently the only known animals with venoms used in predation and defence that contain multiple gene families derived from horizontal gene transfer. The results also provide the first evidence for the implication of horizontal gene transfer in the evolutionary origin of venom in an animal lineage. Three of the bacterial gene families encode virulence factors, suggesting that horizontal gene transfer can provide a fast track channel for the evolution of novelty by the exaptation of bacterial weapons into animal venoms. Animal venoms have evolved many times primarily by recruitment of endogenous proteins with physiological functions. Undheim and Jenner find that centipede venoms have recruited at least five gene families from bacterial and fungal donors, involving at least eight horizontal gene transfer events.

Automated summary

Animal venoms have evolved through recruitment of endogenous proteins with physiological functions, with centipedes being the only known animals with venoms containing gene families derived from horizontal gene transfer events. Horizontal gene transfer serves as a fast track channel for the evolution of novelty in animal venoms.