Modern Evolution of a Single-Copy Gene: The Immunoglobulin C, Locus in Wild Mice1

The immunoglobulin kappa light-chain constant region gene (C,) has been cloned and sequenced from five wild mouse species. Analysis of these data has permitted an assessment of single-copy gene evolution during a limited time period as defined by the genus MUX Sequence conservation was found to be as high (or higher) in the 5’ and enhancer regions as in the coding region. The pattern of substitutions throughout these genes suggests that parallel evolution has occurred frequently and that substitutions at replacement sites have not decreased significantly, owing to saturation during this period of 10 Myr. Phylogenetic relationships have been determined among these wild species as well as among members of the genus Rat&s.