Sexual functionality of Leptopilina clavipes (Hymenoptera: Figitidae) after reversing Wolbachia‐induced parthenogenesis

Abstract

Females infected with parthenogenesis‐inducing Wolbachia bacteria can be cured from their infection by antibiotic treatment, resulting in male production. In most cases, however, these males are either sexually not fully functional, or infected females have lost the ability to reproduce sexually. We studied the decay of sexual function in males and females of the parasitoid Leptopilina clavipes. In western Europe, infected and uninfected populations occur allopatrically, allowing for an investigation of both male and female sexual function. This was made by comparing females and males induced from different parthenogenetic populations with those from naturally occurring uninfected populations. Our results indicate that although males show a decay of sexual function, they are still able to fertilize uninfected females. Infected females, however, do not fertilize their eggs after mating with males from uninfected populations. The absence of genomic incompatibilities suggests that these effects are due to the difference in mode of reproduction.

Reproductive Parasitism: Maternally Inherited Symbionts in a Biparental World

“…In three species (Leptopilina clavipes, Asobara japonica, and Apoanagyrus diversicornis), interpopulation variation in the presence of a symbiont that induces asexuality has allowed the functionality of males and females derived from asexual lineages to be tested. In all three cases this revealed female function to have deteriorated before male, with infected females unable to use sperm from males, while derived males were partially fertile (Pijls et al 1996;Pannebakker et al 2005;Kremer et al 2009). In a variety of cases the loss of sexual traits has been shown to have a simple genetic basis (Jeong and Stouthamer 2005; Russell and Stouthamer 2011).…”

Neutral and selection-driven decay of sexual traits in asexual stick insects

“…In bushcrickets, where males of sexual species attract females with songs, the asexual species Poecilimon intermedius has lost phonotaxis [18,55]. Female mating behaviour is also strongly reduced or lost in many species with endosymbiont-induced parthenogenesis [41,42,47] (but see [43]). Although Potamopyrgus snails, where females appear to play a passive role in mate finding and copulation, may represent an exception to this pattern [56], these parallel and rapid losses of different female traits involved in mate attraction and mating suggest that selective mechanisms, rather than drift, are driving trait changes.…”

“…Tests for trait decay in asexually produced males have been conducted in hymenopterans with endosymbiont-induced parthenogenesis [37,41,42], where males are produced by asexual females cured of their endosymbionts [43]. With few exceptions [44], these males appear fully functional, produce viable sperm [37,41,45,46] and sometimes even father similar numbers of offspring as sexual males [47,48] when mated to females from related sexual strains or species. Only in exceptional instances, notably in 'ancient' asexuals, has male functionality appeared to have decayed, as suggested by the lack of sperm in the darwinulid males [49] and the production of non-functional spermatophores by males in the oribatid mites [20].…”

“…Notably, males are not only produced in recently derived asexual linages but have even been found in darwinulid ostracods [38] and oribatid mites [20], groups that may have been asexual for over 100 million years [39,40]. Tests for trait decay in asexually produced males have been conducted in hymenopterans with endosymbiont-induced parthenogenesis [37,41,42], where males are produced by asexual females cured of their endosymbionts [43]. With few exceptions [44], these males appear fully functional, produce viable sperm [37,41,45,46] and sometimes even father similar numbers of offspring as sexual males [47,48] when mated to females from related sexual strains or species.…”

A new case of Wolbachia dependence in the genus Asobara: evidence for parthenogenesis induction in Asobara japonica

“…However, in the case of Wolbachiainduced thelytoky, any genes involved in sexual reproduction can accumulate mutations without being selected against. Thus, the sexual functionality of males and females from thelytokous populations is expected to deteriorate over time, culminating in Wolbachia dependence for daughter production, which has been reported in various species (Zchori-fein et al, 1992(Zchori-fein et al, , 1995Pijls et al, 1996;Arakaki et al, 2000;Pannebakker et al, 2005).…”