Subtype-Specific Pharmacological Properties of the Melanocortin Receptors in Chicken.

The melanocortin (MC) receptors belong to the family of G-proteincoupled receptors and have five subtypes (MC1-5) in mammals and chicken. We have expressed the chicken MC1-5 (cMC1-5) receptors and seven allelic variants of the cMC1 receptor and performed pharmacological characterization of these receptors. Three variants of the cMC1 receptor, all sharing a Glu to Lys mutation in position 92, are associated with dark feather coloration, and these were pharmacologically described as constitutively active. The pharmacological characterization of the cMC1-5 receptors provides insight of how this receptor family has evolved and useful information for the use of chicken in physiological experiments. [ABSTRACT FROM AUTHOR]