Reinvestigation of an Endogenous Meiotic Drive System in the Mosquito, <I>Aedes aegypti</I> (Diptera: Culicidae)

Abstract

We have initiated efforts to determine the molecular basis for the M(D) meiotic drive system in the mosquito, Aedes aegypti. The effect of the M(D) gene is a highly male-biased sex ratio, but varies depending on the frequency and sensitivity of a susceptible responder m(s) allele. The M(D) system has potential as a mechanism for driving trangenes for pathogen resistance into natural Ae. aegypti populations. Because all previously existing laboratory strains carrying the M(D) gene have been lost, we have selected for a new strain, T37, that carries a strong driver. Matings between T37 males and drive-susceptible m(s) females result in progeny with highly biased sex ratios, wherein only approximately 14.7% females are produced. We discuss the potential for identifying M(D) candidate genes based on comparisons with the well-described Drosophila melanogaster segregation distorter (SD) meiotic drive system and considerations for release of transgenic Ae. aegypti into natural populations where M(D) and insensitive m3 alleles are likely segregating.

Introducing transgenes into insect populations using combined gene-drive strategies: Modeling and analysis

“…However, EU requires the release of quite a few insects compared to some other methods in order for the engineered strain to replace the wild strain especially if the transgenic constructs result in fitness costs . Mori et al (2004) and Cha et al (2006) have studied the meiotic drive (MD) system in Aedes aegypti, the primary vector of dengue and yellow fever, and proposed it as a means for driving anti-pathogen genes into wild populations. In this system, gene(s) on the Aedes equivalent of a Y chromosome block the maturation of gametes containing a sensitive response allele on the Aedes equivalent of an X chromosome (Craig et al, 1960;Hickey and Craig, 1966a,b).…”

“…This results in an excess of males in the population and selects for insensitive response alleles and any genes linked to these alleles. One way of using this MD system to introduce transgenes into natural A. aegypti populations is the release of males with a Y-linked MD gene and an X-linked insensitive response allele to which an anti-pathogen gene is linked (Mori et al, 2004). An earlier modeling study (Huang et al, 2007) demonstrated that under suitable conditions, the frequency of the transgene in the natural population could increase to a very high level that can lead to fixation in a finite population due to stochastic events.…”

Heritable strategies for controlling insect vectors of disease

“…In Ae. aegypti , some natural populations contain a segregation distorter that is closely linked to the male-determining locus and causes the latter to be transmitted to 80–90% of the progeny in crosses with sensitive strains [68,69]. Geographical surveys have shown that the distorter is present in some populations and not others, and that where it is present there is also substantial resistance, so sex ratios are not severely biased [69].…”

Transcript profiling of the meiotic drive phenotype in testis of Aedes aegypti using suppressive subtractive hybridization

“…Some populations of the dengue vector mosquito Aedes aegypti are known to carry an endogenous meiotic drive system that distorts meiosis in favor of male-determining gametes (Craig et al, 1960; Hickey and Craig, 1966a; Mori et al , 2004; Cha et al , 2006a). Sex determination in Ae.…”