Population genetics of Drosophila ananassae: Chromosomal association studies in Indian populations

Abstract

Forty-five natural populations of Drosophila ananassae and laboratory stocks made from these flies were analyzed for chromosome inversions. Quantitative data on the frequencies of these inversions were utilized to test intra- and interchromosomal interactions in D. ananassae. In most of the natural as well as laboratory populations no significant deviation from randomness of intra- and interchromosomal associations (2L-3L, 2L-3R, 3L-3R) was found hence, providing evidence for random associations. However, in some instances, significant deviation from randomness was found in both natural and laboratory populations, which could be due to excess of certain combinations, deficiency of others and complete absence of some combinations. Possible role of genetic drift could be implicated due to tight-linkage between linked gene arrangements. This strengthens the previous suggestion that there is lack of genetic coadaptation in D. ananassae.