Genetics. 117(4): 697–710 (Dec 1987)
A Comprehensive Study of Genic Variation in Natural Populations of Drosophila melanogaster.
III. Variations in Genetic Structure and Their Causes between Drosophila melanogaster and Its Sibling Species Drosophila simulans

M. Choudhary and Rama S. Singh
Department of Biology, McMaster University, Hamilton, Ontario L8S 4K1, Canada


The natural populations of Drosophila melanogaster and Drosophila simulans were compared for their genetic structure. A total of 114 gene-protein loci were studied in four mainland (from Europe and Africa) and an island (Seychelle) populations of D. simulans and the results were compared with those obtained on the same set of homologous loci in fifteen worldwide populations of D. melanogaster. The main results are as follows: (1) D. melanogaster shows a significantly higher proportion of loci polymorphic than D. simulans (52% vs. 39%, P < 0.05), (2) both species have similar mean heterozygosity and mean number of alleles per locus, (3) the two species share some highly polymorphic loci but they do not share loci that show high geographic differentiation, and (4) D. simulans shows significantly less geographic differentiation than D. melanogaster. The differences in genetic differentiation between the two species are limited to loci located on the X and second chromosomes only; loci on the third chromosome show similar level of geographic differentiation in both species. These two species have previously been shown to differ in their pattern of variation for chromosomal polymorphisms, quantitative and physiological characters, two-dimensional electrophoretic (2DE) proteins, middle repetitive DNA and mitochondrial DNA. Variation in niche-widths and/or genetic "strategies" of adaptation appear to be the main causes of differences in the genetic structure of these two species.

A comprehensive study of genic variation in natural populations of Drosophila melanogaster. V. Structural–functional constraints on protein molecules and enzymes and the levels and patterns of variation among genes Singh, Rama S. Genome (Feb 1992)

A comprehensive study of genic variation in natural populations of Drosophila melanogaster. VII. Varying rates of genic divergence as revealed by two-dimensional electrophoresis.
Molecular Biology and Evolution (May 1992)

Genetic Polymorphism bibliography