TY - JOUR T1 - Experimental Evolution of Insect Immune Memory VS. Pathogen Resistance JF - bioRxiv DO - 10.1101/137703 SP - 137703 AU - Imroze Khan AU - Arun Prakash AU - Deepa Agashe Y1 - 2017/01/01 UR - http://biorxiv.org/content/early/2017/05/13/137703.abstract N2 - Under strong pathogen pressure, insects often evolve resistance to infection. Many insects are also protected via immune memory (‘immune priming’), whereby sub-lethal exposure to a pathogen enhances survival after secondary infection. To understand the evolution and consequences of these immune responses, we imposed strong pathogen selection on flour beetles (Tribolium castaneum), infecting them with Bacillus thuringiensis (Bt) for 11 generations. Populations injected first with heat-killed and then live Bt each generation evolved high basal resistance against multiple Bt strains. In contrast, all populations injected only with a high dose of live Bt evolved less effective but strain-specific priming response. Control populations injected with heat-killed Bt did not evolve priming; and in the ancestor, priming was effective only against a low Bt dose. Thus, pathogens can select for rapid modulation of insect priming ability, leading to divergent immune strategies (generalized resistance vs. specific immune priming) with distinct mechanisms and adaptive benefits. ER -