Female resistance behaviour and progeny sex ratio in two Bradysia species (Diptera: Sciaridae) with paternal genome elimination

Abstract

The relationship between female mating preferences and sex allocation has received considerable theoretical and empirical support. Typically, choosier females adjust their progeny sex ratio towards sons, who inherit the attractive traits of their father. However, in species with paternal genome elimination, where male sperm do not contain the paternal genome, predictions for the direction of progeny sex ratio biases and their relationship with female choosiness are atypical. Paternal genome elimination also creates a potential for male-female conflict over sex allocation, and any influence of female mate choice on sex ratio outcomes have interesting implications for sexually antagonistic coevolution. Within the Sciaridae (Diptera) are species that produce single-sex progeny (monogenic species) and others in which progeny comprise both sexes (digenic species). Paternal genome elimination occurs in both species. We explore female mate resistance behaviour in a monogenic and digenic species of mushroom gnat from the genus Bradysia. Our experiments confirmed our theoretical predictions, revealing that in the monogenic and digenic species, females producing female-biased progeny were more likely to have resisted at least one mating attempt.

Evolutionary problems in centrosome and centriole biology

“…Sperm function and motility have previously been shown to be correlated with axoneme structure across invertebrates (Carvalho‐Santos et al ., ). PGE imposes unique selection on the mature sperm and its axoneme: under PGE, some eggs are destined to be male and thus to eliminate the genome of any sperm entering them (Normark, ; Shuker et al ., ; Featherston et al ., ). There might be strong selection for sperm to be able to detect this cue and thus strong selection for a sensory capability for sperm.…”

Paternal genome elimination promotes altruism in viscous populations

“…Thus, although the transmission genetics of PGE are equivalent to "conventional" haplodiploidy (i.e., arrhenotoky), the somatic genetics differs, with both males and females being diploid. Recent years have seen increased interest in PGE systems, not only because they include economically important pests (e.g., the coffee borer beetle), but also because, with the advent of new genomic tools, their remarkable genetics enables potentially exceptional tests of evolutionary theory (Featherston et al 2013;de la Filia et al 2015;Klein et al 2021;Hitchcock et al 2022).…”

“…Recent years have seen increased interest in PGE systems, not only because they include economically important pests (e.g., the coffee borer beetle), but also because, with the advent of new genomic tools, their remarkable genetics enables potentially exceptional tests of evolutionary theory (Featherston et al. 2013; de la Filia et al. 2015; Klein et al.…”