Silver/Gold Genetics
Silver Gene Explained
The silver gene
The "silver gene" in chickens refers to a genetic mutation that affects the coloration of the feathers. Specifically, it alters the production of melanin, which is the pigment responsible for color in feathers.
Chickens normally produce two types of melanin: eumelanin, which produces black or dark brown colors, and pheomelanin, which produces reddish or yellowish colors. The silver gene affects the distribution of these pigments in the feathers, resulting in a dilution or reduction of eumelanin.
Silver versus Gold
in chickens, "silver" and "gold" refer to specific alleles or versions of genes that influence the coloration of feathers. These alleles interact with other genes to produce different colors and patterns in chickens.
- Silver (S) Gene: The silver gene (S) is a dominant allele that affects the distribution of melanin pigments in the feathers. It causes a dilution or reduction of eumelanin, the pigment responsible for black or dark brown colors.
- Gold (G) Gene: The gold gene (G) is a recessive allele that affects the distribution of both eumelanin and pheomelanin pigments in the feathers. It produces a range of colors from reddish to yellowish.
Understanding the inheritance patterns of the silver and gold phenotypes is crucial for breeders looking to produce specific color varieties in their chicken flocks.
Sex-linked Gene
Silver is a sex linked gene.
Males (ZZ): Since males have two Z chromosomes, they can exhibit different phenotypes based on their genotype. If a male inherits one or two copies of the silver allele (S), he will display the silver phenotype (although Ss is often yellowish/cream versus white), while if he inherits two copies of the gold allele (s), he will display the gold phenotype.
Females (ZW): Females, having one Z chromosome and one W chromosome, can also exhibit different phenotypes based on their genotype. However, since they have only one Z chromosome, they can only inherit one copy of the silver allele. Therefore, hens are either S (silver) or s (gold) in appearance (phenotype).