An Analysis of Size Genes

Abstract

Using the method of partial correlations on data from the back-cross generation of a mouse interspecific cross (large brown Mus musculus X small black Mus bactrianus), it was determined that the alleles, black and brown (affecting color, C), had little effect on weight (W) independent of that on body length (B), or on femur length (F) independent of tibia length (T). If the former pair of characters are affected jointly by general size genes and the latter pair also by other genes, t wb.c and t Ft.c should be less different from y wB and y FT, respectively, than weight and femur length correlated with other characters since much of the excess difference should be due to crossing-over between the postulated general and group size genes found on the chromosome with the gene for brown coat color. Since this proved to be true, it was inferred that both group and general factors were present.