Egg provisioning explains the penetrance of symbiont-mediated sex allocation distortion in haplodiploids

Maternally transmitted symbionts such as Wolbachia can alter sex allocation in haplodiploid arthropods. By biasing population sex ratios towards females, these changes in sex allocation may facilitate the spread of symbionts. In contrast to symbiont-induced cytoplasmic incompatibility (CI), the mechanisms that underpin sex allocation distortion remain poorly understood. Using a nuclear genotype reference panel of the haplodiploid mite Tetranychus urticae and a single Wolbachia variant that is able to simultaneously induce sex allocation distortion and CI, we unraveled the mechanistic basis of Wolbachia-mediated sex allocation distortion. Host genotype was an important determinant for the strength of sex allocation distortion. We further show that sex allocation distortion by Wolbachia in haplodiploid mites is driven by increasing egg size, hereby promoting egg fertilization. This change in reproductive physiology was also coupled to increased male and female adult size. Our results echo..., The seven near-isogenic mite lines (Stt, Stt-w, Stt-c, LonX-w, LonX-c, Beis-w, and Beis-c) of the Tetranychus urticae nuclear genotype panel were maintained by serial passage on detached Phaseolus bean leaves under controlled laboratory conditions. Age-synchronized cohorts of the mite lines were created on leaf discs. Multiple genetic crosses were performed to test our hypotheses. Here, female teleiochrysalids were consistently paired with adult males. During development, eggs, adult male offspring, and adult female offspring were isolated, counted, and measured., Raw data files can be opened using any text editing software.
R script files can be opened using R.