Evolution in Action: Highlighting a Role for the Agouti Gene in Development?

The study highlighted the role of the Agouti gene in the evolution of pigmentation in oldfield deer mice, particularly in the beach-dwelling subspecies with pale coats. Researchers found that the Agouti gene, along with Mc1r, played a significant role in pigmentation differences. The pale beach mice exhibited a variant of the Mc1r gene and increased expression of the Agouti gene, leading to a dorsal shift in the boundary of pale ventral skin. This shift was due to differences in cis-acting elements of the Agouti gene, not transacting factors. The study suggested that the Agouti gene might have a developmental role, influencing melanocyte localization and proliferation, in addition to its known physiological role in pigment type synthesis. The findings provided a molecular explanation for rapid evolutionary changes in pigmentation and hinted at a developmental function for the ASP/Mc1r interaction.