Mating ability of different karyotypes due to sub-terminal (alpha or In(2L)A) inversion in 2L from two natural populations of Drosophila ananassae was investigated. The results show that the average number of females inseminated by a single male in 12-hour period varies for different karyotypes in males. The analysis of variance indicates that the differences are highly significant for males in both the populations studied. However, the averages for different karyotypes in females show no variation and thus homo- and heterokaryotypic females are equally receptive. The males heterozygous for inversion show greater mating propensity as compared with homokaryotypic males which provides evidence for heterosis associated with AL inversion in D. ananassae with respect to male mating activity. Furthermore, the comparison of male mating propensity with chromosome arrangement frequency in both the natural populations suggests that there is a correlation between mating propensity and chromosome arrangement frequency in natural populations of D. ananassae.
Animals Chromosomes