He S., Sieksmeyer T., Che Y., Esparza Mora M.A., Stiblik P., Banasiak R., Harrison M.C., Šobotník J., Wang Z., Johnston P.R. & McMahon D.P. 2021: Evidence for reduced immune gene diversity and activity during the evolution of termites. Proceedings of the Royal Society B, Biological Sciences (Accepted).
We tackled the evolution of the immune gene repertoire in 18 cockroach and termite species, spanning the spectrum of solitary, subsocial and eusocial lifestyles. We found that key transitions in termite sociality are correlated with immune gene family contractions. In cross-species comparisons of immune gene expression, we find evidence for a caste-specific social defense system in termites, which appears to operate at the expense of individual immune protection. Our study indicates that a major transition in organismal complexity may have entailed a fundamental reshaping of the immune system optimized for group over individual defense.