Untitled

Abstract

The sexual isolation among the related species Drosophila melanogaster, D. simulans and D. mauritiana is asymmetrical. While D. mauritiana males mate well with both D. melanogaster and D. simulans females, females of D. mauritiana discriminate strongly against males of these two species. Similarly, D. simulans males mate with D. melanogaster females but the reciprocal cross is difficult. Interspecific crosses between several populations of the three species were performed to determine if (i) males and females of the same species share a common sexual isolation genetic system, and (ii) males (or females) use the same genetic system to discriminate against females (or males) of the other two species. Results indicate that although differences in male and female isolation depend on the populations tested, the isolation behaviour between a pair of species is highly correlated despite the variations. However, the rank order of the isolation level along the populations was not correlated in both sexes, which suggests that different genes act in male and female sexual isolation. Neither for males nor for females, the isolation behaviour of one species was paralleled in the other two species, which indicates that the genetic systems involved in this trait are species-pair specific. The implications of these results are discussed.

The Genetic Basis of Female Mate Preference and Species Isolation inDrosophila

“…These efforts have yielded maps that vary in refinement from whole chromosomes, chromosomal arms, subchromosomal regions, to specific QTLs. Although the genetic basis of female discrimination may be species pair specific [135], one common attribute of these loci is their location in the genome: most of these loci fall within areas of low recombination, such as species inversion polymorphisms, regions near the centromere, and regions near the telomere. Behavioral isolation loci between D. santomea and D. yakuba were found near the centromere on 3R [7], and near the telomere for both the D. simulans and D. mauritiana species pair [6] and the M and Z forms of D. melanogaster [92].…”

“…To investigate whether there is genetic variation for D. simulans female preference, different lab strains of D. simulans females [86, 135] and D. melanogaster males [86] were compared for their rate of interspecific mating. Crossability, the ability for the parental strains or species to successfully produce offspring, varied among strains for both D. melanogaster males and D. simulans females [86, 87], but were still highly correlated [135].…”

“…Crossability, the ability for the parental strains or species to successfully produce offspring, varied among strains for both D. melanogaster males and D. simulans females [86, 87], but were still highly correlated [135]. When strains of D. simulans were crossed, the pure species F 1 females were then crossed D. melanogaster males and the crossability was compared to the two parental strains.…”

Thefruitlessgene affects female receptivity and species isolation

“…The Drosophila genus has multiple closely related species that are sexually isolated, making it a commonly used model for studying behavioural isolation [14,20]. Drosophila melanogaster and D. simulans are two species that are behaviourally isolated: while D. melanogaster females mate at high frequencies with D. melanogaster males, D. simulans females do not [21,22]. However, hybrid females from the permissive cross between D. melanogaster females and D. simulans males [23,24] will mate with D. melanogaster males [25].…”

The Study of Drosophila Mate Preference as a Research Assistant in A. Moehring’s Lab

“…On the other hand, D. melanogaster females do not display this similar discrimination in mating behaviour and accept courtship and copulate with D. simulans males. 12 We are currently working to isolate potential mate preference loci within the tip of the right arm of the third chromosome which previous research has indicated is a region encoding female mate preference in Drosophila.…”