Data from: The role of defensive ecological interactions in the evolution of conotoxins

Venoms comprise of complex mixtures of peptides evolved for predation and
defensive purposes. Remarkably, some carnivorous cone snails can inject
two distinct venoms in response to predatory or defensive stimuli,
providing a unique opportunity to study separately how different
ecological pressures contribute to toxin diversification. Here, we report
the extraordinary defensive strategy of the Rhizoconus subgenus of cone
snails. The defensive venom from this worm-hunting subgenus is unusually
simple, almost exclusively composed of αD-conotoxins instead of the
ubiquitous αA-conotoxins found in the more complex defensive venom of
mollusc- and fish-hunting cone snails. A similarly compartmentalised venom
gland as those observed in the other dietary groups facilitates the
deployment of this defensive venom. Transcriptomic analysis of a C.
vexillum venom gland revealed the αD-conotoxins as the major transcripts,
with lower amounts of 15 known and 4 new conotoxin superfamilies also
detected with likely roles in prey-capture. Our phylogenetic and molecular
evolution analysis of the αD-conotoxins from five subgenera of cone snails
suggests they evolved episodically as part of a defensive strategy in the
Rhizoconus subgenus. Thus, our results demonstrate an important role for
defence in the evolution of conotoxins.