Inheritance in a Mouse Species Cross

Abstract

A small Asiatic species, Mus bactrianus, carrying the dominant genes for color, D, B, and Aw, when mated to mice of a strain of large, inbred M. musculus, possessing the recessive allelomorphic genes, d, b and a, produced offspring of which both sexes were fertile. The F1 animals were intermediate in weight and in external measurements although usually equaling or surpassing the larger parent in skeletal measurements. The back-cross generation (F1 [image] musculus) showed no significant deviations from the expected numbers in color classes, thus affording no evidence for the formation of association systems of chromosomes. Only the back-cross generation gave indications of a heightened sex ratio (120.14 [plus or minus] 5.34). There were strong indications of linkage between the quantitative and the qualitative characters investigated.