Oral Presentation Society for Molecular Biology and Evolution Conference 2016

When sex matters: Dramatic sexual dimorphism in the venom and venom system of the centipede Scolopendra hardwickei (#77)

Eivind Undheim 1 2 , D Richards 2 , N Ngum 2 , D Tooth 2 , DH Kim 2 , I Mellor 2
  1. Centre for Advanced Imaging, University of Queensland, St Lucia, QLD, Australia
  2. School of Life Sciences, University of Nottingham, University Park, Nottingham, United Kingdom

Although sexual dimorphism has been well documented in spiders and certain snake species, it remains poorly documented among most venomous animals. This is particularly the case for species where there are no obvious differences in the appearances of males and females. Using a combination of gas-chromatography mass spectrometry, proteomics, transcriptomics, electrophysiology, and magnetic resonance imaging we describe the venom and venom system of the striking, aposematic centipede Scolopendra hardwickei. We also provide the first insight into the venom arsenal of any single centipede specimen, as well as the first detailed characterisation of the low-molecular weight non-peptidic components of any centipede venom. Despite no obvious differences in non-reproductive behaviour or morphology between males and females, our results demonstrate dramatic sexual dimorphisms in venom composition, pharmacology, and venom gland morphology. We show that there are substantial differences in the relative abundance and expression levels of high versus low molecular weight components, and that males and females appear to employ very different venom strategies. Although we can only speculate as to the differences in function of male and female S. hardwickei venom, our results highlight the important role that sex-specific natural selection can play in the evolution of centipede venoms.