Immune priming specificity within and across generations reveals the range of pathogens affecting evolution of immunity in an insect

1. Many organisms can improve their immune response as a function of their immunological experience or that of their parents. This phenomenon, called immune priming, has likely evolved from repetitive challenges by the same pathogens during the host lifetime or across generation. 2. All pathogens may not expose host to the same probability of re-infection and immune priming is expected to evolve from pathogens exposing the host to the greatest probability of re-infection. Under this hypothesis, the priming response to these pathogens should be specifically more efficient and less costly than to others. 3. We examined the specificity of immune priming within and across generations in the mealworm beetle, Tenebrio molitor, by comparing survival of individuals to infection with bacteria according to their own immunological experience or that of their mother with these bacteria. 4. We found that insects primed with Gram-positive bacteria became highly protected against both Gram-positive an...