Insect Antimicrobial Defences: A Brief History, Recent Findings, Biases, and a Way Forward in Evolutionary Studies

Naomi L-P. Keehnen, Jens Rolff, Ulrich Theopold, Christopher W. Wheat

Advances in Insect Physiology, http://doi.org/10.1016/bs.aiip.2017.02.003

Abstract

We propose that an evolutionary and phenotype-driven approach, harnessing current technological developments, has much to offer for our understanding of insect immunity. After briefly reviewing the history of the discovery of canonical immune system, the current understanding of its components is reviewed and then we argue that the current paradigm of research may be biassed due to (a) its limited taxonomic perspective, (b) the evolutionary time scale being studied, and (c) a focus primarily if not exclusively, upon the canonical, humoural gene set. For the rest of the review, we then discuss the importance of a phenotype down approach as an understudied perspective, exemplified by the need for understanding the basis of cellular responses and wounding as a source of selection on immunity in the wild. We propose that research on those topics almost certainly will provide new insights into the evolution of the insect immune system.