Molecular population genetics of an electrophoretically monomorphic protein in the alcohol dehydrogenase region of Drosophila pseudoobscura.
Nucleotide sequence data from the alcohol dehydrogenase (Adh) region of 18 isochromosomal strains of Drosophila pseudoobscura were used to determine whether the lack of amino acid polymorphism in ADH results from a low neutral mutation rate or a recent directional selection event. We estimated the neutral mutation parameter, 4Nmu, in synonymous sites for 17 subregions of Adh. The nucleotide diversity data were tested for departures from an equilibrium neutral model with two statistical tests. The Tajima test and the Hudson, Kreitman and Aguade test each failed to reject a neutral model. These results suggest that the ADH enzyme of D. pseudoobscura lacks amino acid polymorphisms because the neutral mutation rate of nonsynonymous sites is low. The neutral mutation parameter for synonymous sites is heterogeneous between domains of the Adh region. These data indicate that selective constrains on synonymous sites can vary between functional domains.
Schaeffer
S W
SW
Department of Biology, Pennsylvania State University, University Park 16802.
Miller
E L
EL
D000426:Alcohol Dehydrogenase / Q000235:genetics*; D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D004247:DNA; D004330:Drosophila / Q000235:genetics*; D004586:Electrophoresis; D014644:Genetic Variation; D008969:Molecular Sequence Data; D009154:Mutation; D011995:Recombination, Genetic / Q000235:genetics; D012641:Selection, Genetic; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity
D004247:DNA; D000426:Alcohol Dehydrogenase