Data for: Sexual conflict drives micro- and macroevolution of sexual dimorphism in immunity

Background: Sexual dimorphism in immunity is believed to reflect
sex-differences in reproductive strategies and trade-offs between
competing life history demands. Sexual selection can have major effects on
mating rates and sex-specific costs of mating and may thereby influence
sex-differences in immunity as well as associated host-pathogen dynamics.
Yet, experimental evidence linking the mating system to evolved sexual
dimorphism in immunity are scarce and the direct effects of mating rate on
immunity are not well established. Here, we use transcriptomic analyses,
experimental evolution and phylogenetic comparative methods to study the
association between the mating system and sexual dimorphism in immunity in
seed beetles, where mating causes internal injuries in females. Results:
We demonstrate that female phenoloxidase (PO) activity, involved in wound
healing and defence against parasitic infections, is elevated relative to
males. This difference is accompanied by concomitant sex-differences in
the expression of genes in the pro-phenoloxidase activating cascade. We
document substantial phenotypic plasticity in female PO activity in
response to mating and show that experimental evolution under enforced
monogamy (resulting in low remating rates and sexual conflict relative to
natural polygamy) rapidly decreases female (but not male) PO activity.
Moreover, monogamous females have evolved increased tolerance to bacterial
infection unrelated to mating, implying that female responses to costly
mating may trade off with other aspects of immune defence, an hypothesis
which broadly accords with the documented sex differences in gene
expression. Finally, female (but not male) PO activity shows correlated
evolution with the perceived harmfulness of male genitalia across 12
species of seed beetles, suggesting that sexual conflict has a significant
influence on sexual dimorphisms in immunity in this group of insects.
Conclusions: Our study provides insights into the links between sexual
conflict and sexual dimorphism in immunity and suggests that selection
pressures moulded by mating interactions can lead to a sex-specific mosaic
of immune responses with important implications for host-pathogen dynamics
in sexually reproducing organisms.