Molecular evolution of a Drosophila homolog of human BRCA2.
The human cancer susceptibility gene, BRCA2, functions in double-strand break repair by homologous recombination, and it appears to function via interaction of a repetitive region ("BRC repeats") with RAD-51. A putatively simpler homolog, dmbrca2, was identified in Drosophila melanogaster recently and also affects mitotic and meiotic double-strand break repair. In this study, we examined patterns of repeat variation both within Drosophila pseudoobscura and among available Drosophila genome sequences. We identified extensive variation within and among closely related Drosophila species in BRC repeat number, to the extent that variation within this genus recapitulates the extent of variation found across the entire animal kingdom. We describe patterns of evolution across species by documenting recent repeat expansions (sometimes in tandem arrays) and homogenizations within available genome sequences. Overall, we have documented patterns and modes of evolution in a new model system of a gene which is important to human health.
Bennett
Sarah M
SM
Biology Department, Duke University, Durham, NC 27708, USA.
Noor
Mohamed A F
MA
D000818:Animals; D024682:BRCA2 Protein / Q000235:genetics*; D001483:Base Sequence; D017931:DNA Primers / Q000235:genetics; D042622:DNA Repeat Expansion / Q000235:genetics; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins / Q000235:genetics*; D019143:Evolution, Molecular; D024522:Genes, BRCA2; D014644:Genetic Variation; D006801:Humans; D016013:Likelihood Functions; D008957:Models, Genetic; D008969:Molecular Sequence Data; D010802:Phylogeny; D017422:Sequence Analysis, DNA; D013045:Species Specificity
D024682:BRCA2 Protein; D017931:DNA Primers; D029721:Drosophila Proteins