Racial divergence in sternopleural bristles among the parental races and the newly evolved Cytoraces 1 and 2 of the nasuta-albomicans complex of Drosophila

Abstract

Interracial hybridization between a pair of cross fertile races, Drosophila nasuta (2n = 8) and Drosophila albomicans (2n = 6) has resulted in the evolution of new karyotypic strains, called Cytoraces, under laboratory conditions. These Cytoraces have inherited chromosomes from both the parents. Here we report the racial divergence in sternopleural bristles among the parental races and the newly evolved Cytorace 1 and 2. This analysis has revealed that the parental race, D. nasuta has lesser number of bristles than D. albomicans, Cytorace 1 and Cytorace 2. These newly evolved Cytorace 1 and Cytorace 2, with more number of sternopleural bristles, show better fitness.