title: Linkage disequilibrium, mutational analysis and natural selection in the repetitive region of the clock gene, period, in Drosophila melanogaster.
abstract: We have used the method of disequilibrium pattern analysis to examine associations between the threonine-glycine (Thr-Gly) encoding repeat region of the clock gene period (per) of Drosophila melanogaster, and polymorphic sites both upstream and downstream of the repeat, in a number of European fly populations. The results are consistent with the view that selection may be operating on various haplotypes which share the Thr-Gly length alleles encoding 17, 20 and 23 dipeptide pairs, and that the repeat itself may be the focus for selection. These conclusions lend support to a number of other population and behavioural investigations which have provided evidence that selection is acting on the Thr-Gly region. The linkage analysis was also used to infer an approximate mutation rate (mu) for the repeat, of 10(-5) < mu < 4 x 10(-5) per gamete per generation. Direct measurements of the mutation rate using the polymerase chain reaction in a pedigree analysis of tens of thousands of individuals do not contradict this value. Consequently, the Thr-Gly repeat does not have a mutation rate that is as high as some of the non-coding minisatellites, but it is several orders of magnitude higher than the nucleotide substitution rate. The implications of this elevated mutation rate for linkage disequilibria and selection are discussed.
authors: Department of Genetics, University of Leicester, UK.
authors: E
authors: E
authors: Rosato
authors: A A
authors: AA
authors: Peixoto
authors: R
authors: R
authors: Costa
authors: C P
authors: CP
authors: Kyriacou
mesh_terms: D000483:Alleles; D000818:Animals; D004252:DNA Mutational Analysis; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000235:genetics*; D008040:Genetic Linkage; D006239:Haplotypes; D015810:Linkage Disequilibrium; D009687:Nuclear Proteins / Q000235:genetics*; D056950:Period Circadian Proteins; D012641:Selection, Genetic
chemical_list: D029721:Drosophila Proteins; D009687:Nuclear Proteins; C539040:PER protein, Drosophila; D056950:Period Circadian Proteins