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GENE VARIATION IN DROSOPHILA POPULATIONS
Author(s) -
Prakash Satya
Publication year - 1971
Publication title -
taxon
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.819
H-Index - 81
eISSN - 1996-8175
pISSN - 0040-0262
DOI - 10.2307/1218534
Subject(s) - drosophila pseudoobscura , biology , gene flow , allele , genetics , locus (genetics) , population , genetic variation , evolutionary biology , gene , demography , sociology
Summary Recent investigations on gene variation as revealed by electrophoresis of proteins show that in mice, man and Drosophila , 30–40% of the loci are polymorphic and 7–12% of the loci are in a heterozygous state in an individual. Populations of D. pseudoobscura from ecological margins are as heterozygous as those in the center and the allele frequencies are very similar in all the populations except in Bogota, Colombia, which is a complete isolate from the main body of the species. The Bogota population of D. pseudoobscura has reduced genetic variation and when Bogota females are mated to males of various populations from the United States and Guatemala, the F 1 males are sterile and the F 1 females are fertile. The reciprocal cross produces fertile hybrids of both sexes. Founder effect and lack of gene flow from other populations is a very important aspect of speciation. When two closely related sibling species D. pseudoobscura and D. persimilis are compared for genetic changes at 24 homologous loci, it is found that no locus is monomorphic or polymorphic for entirely different alleles, however, at several polymorphic loci, the two species have unique alleles in addition to the similar alleles.