Agouti Signaling ProteinHair ColorReceptors, MelanocortinReceptors, CorticotropinPigmentationAgouti-Related ProteinIntercellular Signaling Peptides and ProteinsReceptor, Melanocortin, Type 1alpha-MSHMelaninsProteinsGenes, Intracisternal A-ParticleMelanocyte-Stimulating HormonesRats, Inbred LECSkin Pigmentation