Hen-feathering mutation HF*H may act as a eumelanising factor and modify the expression of autosomal barring

1. An investigation was conducted amongst the progeny from a mating between a Hen-feathered Silver Spangled Hamburgh bantam male and a normal feathered Silver Fayoumi bantam female into the genotype of the plumage pattern of the latter. 2. Both breeds possess the marbled chickdown phenotype which has been shown to depend upon homozygosity of three genes: the birchen allele E*R at the extension locus, the dark brown Columbian-like eumelanin restrictor gene DB*B and the plumage pattern arranging gene PG*P. Furthermore, the Spangled Hamburgh was known to possess genes for Hen-feathering HF*H and for the melanotic ML*M eumelanin extension. The Fayoumi had been hypothesised to contain Columbian eumelanin restrictor genes CO*C. 3. The absence of lace-tailed laced segregants similar to the Sebright, of genotype homozygous HF*H, ER*R, CO*C, DB*B--ML*M--PG*P contradicts the hypothesis that the genome of the Fayoumi includes CO*C. 4. Comparisons of both Hen-feathered and normal feathered versions of the feather patterns discussed in this work demonstrated that the Hen-feathered version is more heavily eumelanised.