Labrador Retriever coat colour genetics fur colour but those with black skin can potentially produce a Dudley. Dudleys breed true for both fur and skin. The ability of the E locus to override the coat colour directed by the B locus is a classical example of epistasis, where multiple genetic loci affect the same observed trait. The E locus also determines whether the phenotype due to the third genetic locus affecting coat colour will be evident. This locus is recognised as affecting coat colour through the expression of pheomelanin, the pigment responsible for red and yellow pigmentation. The effects on pheomelanin pigmentation are only seen
Pigment of power and life. Natives of Peru had been producing cochineal dyes for textiles since at least 700 CE, but Europeans had never seen the color before. When the Spanish invaded the Aztec empire in what is now Mexico, they were quick to exploit the color for new trade opportunities. Carmine became the region's second most valuable export next to silver. Pigments produced from the cochineal insect gave the Catholic cardinals their vibrant robes and the English "Redcoats" their distinctive uniforms. The true source of the pigment—an insect—was kept secret until the 18th century, when biologists discovered the source. While