Trans-generational immune priming is constrained by the maternal immune response in an insect.
Résumé
Immune-challenged vertebrate and invertebrate females can transfer immunity to their off spring. Th is trans-generational immune priming (TGIP) is benefi cial for the off spring if the maternal infection risk persists across generations. However, because immunity is costly, fi tness consequences of TGIP have been found in primed off spring. Furthermore, transferring immunity to off spring may be costly for immune-challenged females who are also carrying the costs of their immune response. A negative relationship between levels of immunity between mothers and off spring might therefore be expected. Consistent with this hypothesis, we show that in the insect, Tenebrio molitor , the magnitude of antibacterial immune response of immune-challenged females negatively correlates with levels of antibacterial activity of their eggs. Th is negative relationship was only present in small females that are inherently of lower quality. Furthermore, female body size did not aff ect immune responsiveness to the challenge, indicating that small females favoured their immunity at the expenses of that of their eggs.