Association of polyandry andsex-ratiodrive prevalence in natural populations ofDrosophila neotestacea

Abstract

Association of polyandry and sex-ratio drive prevalence in natural populations of Drosophila neotestacea Cheryl A. Pinzone and Kelly A. Dyer Department of Genetics, University of Georgia, Athens, GA 30602, USA Selfish genetic elements bias their own transmission to the next generation, even at the expense of the fitness of their carrier. Sex-ratio (SR) meiotic drive occurs when an X-chromosome causes Y-bearing sperm to die during male spermatogenesis, so that it is passed on to all of the male's offspring, which are all daughters. How SR is maintained as a stable polymorphism in the absence of genetic suppressors of drive is unknown. Here, we investigate the potential for the female remating rate to affect SR dynamics in natural populations, using the fly Drosophila neotestacea. In controlled laboratory conditions, females from populations where SR is rare mate more often than females from populations where SR is common. Furthermore, only when males mate multiply does the average fertility of SR males relative to wild-type males decrease to a level that can prevent SR from spreading. Our results suggest that differences in the female mating rate among populations may contribute to SR dynamics in the wild, and thus also affect the outcome of this intragenomic conflict. In line with this, we also present evidence of a localized population crash due to SR that may have resulted from habitat fragmentation along with a reduced mating rate.

Sex-Ratio Meiotic Drive and Y-Linked Resistance in Drosophila affinis

“…SRMD has been implicated in processes as diverse as speciation (Frank 1991;Hurst and Pomiankowsi 1991;Tao et al 2001;Phadnis and Orr 2009;McDermott and Noor 2010), changes in patterns of linkage disequilibrium (Dyer et al 2007), mating system evolution (Price et al 2008;Pinzone and Dyer 2013), extinction (Hamilton 1967), and interspecific competition (James and Jaenike 1990;Unckless and Clark 2014). Since Y chromosomes have fitness close to zero when paired with a sex-ratio X (X SR ), those Y-chromosome genotypes able to decrease offspring sex-ratio bias will be selectively favored when the frequency of X SR is appreciable (Clark 1987;Hall 2004).…”

Sex Chromosome Drive

“…Only recently, a population crash may have been related to a high SR frequency in Drosophila neotestacea (Pinzone and Dyer 2013). The absence of examples might be because, at least in part, of the short period of time during which the phenomenon can be observed.…”

“…Accordingly, SR prevalence is negatively correlated with polyandry in natural populations of this species (Price et al 2014). Selfish genetic elements in general can be common drivers of the evolution of polyandry (reviewed in Wedell 2013), and this has been suggested in other SR systems (e.g., Wilkinson et al 2003;Angelard et al 2008; but see discussion in Pinzone and Dyer 2013). In addition, if polyandry may evolve through sexual selection in females, sperm competition theory predicts that males should benefit from a reduction in female mating rate to increase their mating success (Parker 2006).…”

Invasion and maintenance of meiotic drivers in populations of ascomycete fungi

“…However, some genetic elements are able to distort the meiotic process in such a way as to become over-represented in meiotic products, a phenomenon called ‘meiotic drive’ (Sandler and Novitski, 1957; Burt and Trivers, 2006). Because of their ability to distort meiosis, meiotic drivers (MDs) gain a selective advantage at the gene level that allows them to increase in frequency in a population even when they impose fitness costs on their host organism, which can lead to population extinction (Hamilton, 1967; Pinzone and Dyer, 2013; Akbari et al, 2013; Kyrou et al, 2018). This genetic conflict that arises between a MD and its host can affect many evolutionary processes (Rice, 2013).…”