Plumage Color Allelism in the Red Jungle Fowl (Gallus Gallus) and Related Domestic Forms.

HE lack of an ancestral “standard of reference”, “normal” or “wild type” T for use in genetic studies of the domestic fowl has been of little concern to many poultry geneticists (for a recent discussion of this topic see JAAP and HOLLANDER 1954). In the field of plumage color inheritance, however, a standard of reference seems necessary in describing the action of mutant genes. What the standard should be has yet to be determined, since the ancestry of the domestic fowl is still unknown. One or more of the four known species of jungle fowl may have contributed to the ancestry of the fowl, or some yet undiscovered fossil prototype may have been the major contributor. In view of this uncertainty, the use of the red jungle fowl (Gullus gullus L.) as a standard of reference for mutant genes in the fowl is entirely unwarranted without definite proof of allelism to genes manifest in the red jungle fowl. However, the lack of proof of allelism of genes to those of red jungle fowl need not disprove the “wild type” nature of a given allele since other jungle fowl species may have been involved. Crosses between domestic breeds and red jungle fowl will be reported herein which demonstrate that a multiple allelic series of genes controls the differentiation of certain plumage colors and patterns. On this evidence, wild type designation of the character expressed in the red jungle fowl is justified. Only a few attempts have been made to correlate the many color patterns in the down of chicks with adult plumage type. Often no correlation exists. In the multiple allelic series herein described, however, the same alleles are shown to regulate plumage color patterns in both the chick and the adult. The three other groups of multiple alleles reported for the domestic fowl affect leg morphology (polydactylism, WARREN 1941 ; 1944), rate of feather growth (JONES and HUTT 1946), and blood groups (BRILES et al. 1950).