Conditional indirect genetic effects of caregivers on brood in the clonal raider ant

Abstract Caregivers shape the rearing environment of their young. Consequently, offspring traits are influenced by genes caregivers via indirect genetic effects (IGEs). However, extent to which IGEs modulated environmental factors, other than genotype social partners (i.e., intergenomic epistasis), remains an open question. Here we investigate how brood in clonal raider ant, Ooceraea biroi, a species genotype, age and number both can be experimentally controlled. First, used four lines establish colonies that differed only measured on foraging activity, as well phenotypes. In second experiment, tested whether these conditional caregivers. We found caregiver affected feeding activity colonies, rate development, survival, body size, caste fate brood. Caregiver interacted with factors influence development survival brood, demonstrating conditional. Thus, provide empirical example phenotypes being IGE-by-environment interactions beyond epistasis, highlighting caregivers/parents alterable brood’s/offspring’s genotype.