title: Effect of the eumelanin restrictor Db on plumage pattern phenotypes of the domestic fowl.
abstract: An investigation was conducted among the progeny from crosses between Gold-Pencilled Hamburgh and Partridge Wyandotte bantams into the relationship between two plumage pattern phenotypes, pencilling and autosomal barring, both of which are arrangements of eumelanin expressed on a background of phaeomelanic pigmentation. A eumelanin restricting gene Db had previously been shown to be responsible for the barred phenotype when acting in conjunction with a pattern arranging gene Ab. The pencilled phenotype had been presumed to be caused by the presence of a pencilling gene Pg. The F2 generation consisted entirely of three phenotypes: barred, pencilled and intermediary, with presumed genotypes DB/Db, db+/db+ and Db/db+ respectively, indicating that Ab and Pg are one and the same gene, for which I propose the retention of the symbol Pg. The gene action of Db when homozygous is therefore to prevent curvature, so changing pencilling into barring.
mesh_terms: D000818:Animals; D002645:Chickens / Q000033:anatomy & histology / Q000235:genetics*; D003433:Crosses, Genetic; D005241:Feathers / Q000033:anatomy & histology*; D005260:Female; D005796:Genes; D008297:Male; D008543:Melanins / Q000235:genetics*; D010641:Phenotype; D010858:Pigmentation
chemical_list: D008543:Melanins; C041877:eumelanin