Effect of chromosome arrangements on mate recognition system leading to behavioral isolation in Drosophila ananassae

Abstract

The mechanisms of speciation that appear in the early stages of reproductive isolation has been of recent interest to evolutionary biologists. Experiments were conducted to study behavioral isolation between karyotypically different homozygous strains derived from natural populations of Drosophila ananassae. Three mass cultures stocks established from flies collected from natural populations were employed and homozygous stocks (ST/ST and AL/AL) were made through selection for homozygosity. By employing male-choice technique, mating success was scored by direct observation in the Elens-Wattiaux mating chamber. There is preference for homogamic matings in all the three populations and the differences between homogamic and heterogamic matings are statistically significant in two populations (Lucknow and Varanasi). These findings provide evidence that there is incipient sexual isolation between karyotypically different strains of D. ananassae derived from natural populations which shows that chromosome arrangements may affect the mate recognition system in D. ananassae.

Delimiting the Origin of a B Chromosome by FISH Mapping, Chromosome Painting and DNA Sequence Analysis in Astyanax paranae (Teleostei, Characiformes)

“…In fish, only satellite DNA, 45S rDNA and transposable elements had previously been found in the B chromosomes of Astyanax scabripinnis [33], Prochilodus lineatus [66], Haplochromis obliquidens [36], Astatotilapia latifasciata [67], Alburnus alburnus [68], while active nucleolar sites were observed in the B chromosomes of Moenkausia sanctaefilomenae [69]. Here, we show the first evidence of histone protein genes allocated in a fish B chromosome, a fact that had previously been reported only in the grasshoppers Locusta migratoria [21] and Rhammatocerus brasiliensis [22].…”

The Genetic Basis of Female Mate Preference and Species Isolation inDrosophila

“…One inversion, called “alpha,” is a large paracentric inversion covering the majority of 2L (3R in D. melanogaster ). To investigate whether this inversion could contribute to behavioral isolation within this species, Nanda and Singh [120] created karyotypically different strains homozygous for one of three naturally occurring inversions. Through mate choice assays, they found a preference for homogamic matings in all three populations.…”

“…If these genes could tolerate a genetic variant causing a slight change in function, selection could then act directly on a new allele, or on other genes within this genetic island, to cause different alleles to reach a high frequency in different populations, causing a slight difference in female mating preference between them. If mutations that occur within these regions cause a change in female preference by influencing assortative mating within species [120], these areas can influence behavioral isolation between species, and thus potentially induce a speciation event [84, 140]. …”

Origin of sexual isolation in Drosophila ananassae due to founder effects

“…Arrow indicates the discrimination between groups of females (Square) to particular males (Oval) Multiple regression analysis by using interspecific mosaic genome lines of D.ananassae and D. pallidosa indicated highly significant effects on 2L for female mating willingness with D.ananassae males and on XL, 2L and 3R for that with D. pallidosa males (Sawamura et al 2008). Behavioural isolation has been found between two karyotypically different homozygous strains of D. ananassae derived from same geographic population which shows that chromosome arrangements may affect mate recognition system in D. ananassae (Nanda and Singh 2011b).…”