Genetic studies of Gammarus

摘要

The population of the marine amphipod Gammarus oceanicus at Vosnæs, Denmark, is polymorphic at the two unlinked enzyme loci mannosephosphate isomerase. Mpi, and glucosephosphate isomerase, Gpi. These polymorphisms were subjected to a selection component analysis, where the components gametic selection, zygotic selection, and sexual selection were estimated in both sexes and where the mating pattern was described. At the Gpi locus no evidence of the action of natural selection was found. The genotypic distribution among the adult population at the Mpi locus did not agree with the expected distribution under the assumption of no selection. A significant deficit of heterozygotes was found. This deviation, however, is explained by the segregation of a silent allele.