Allelism of Silver, Gold, and Imperfect Albinism in the Fowl

Abstract

WERRET et al.¹ described a series of matings, starting with a non-silver male resulting from a cross of a Brown Leghorn sire by a Light Sussex dam, which suggested that the gene for silver (S) had mutated to that for semi-albinism, designated by them as s^al. As the mutant gene also proved to be recessive to that for gold (s), together they formed a series of three alleles at one locus on the sex chromosome. Mueller and Hutt² first described imperfect or semi-albinism (al), and afterwards Hutt³ reported on the linkage relationships of his al to other genes on that chromosome. Although Hutt had no specific tests of linkage of al with S, both these genes were tested with others located nearby. Identical linkages (0.7 per cent) were found with the gene for dwarf (dw) ; but for the gene for rapid feathering (k), where there were more gametes tested and the map distance was considerably less, k was closer (1.6 per cent) to al than to S (2.8 per cent), a situation that did not suggest possible allelism. Hutt therefore placed al between S and k, a little closer (1.2 per cent) to the former.