Carotenoid-based coloration is a textbook example of a condition-dependent signal used in mate choice. However, the mechanisms that link ornamentation to condition remain uncertain. A series of groundbreaking discoveries revealed the three genes that enable birds to modify yellow dietary carotenoids into red pigments used in ornamental displays. CYP2J19 and BDH1L oxidize dietary yellow carotenoids in a two-step process, producing red ornamental pigments. The protein TTC39B greatly enhances this process.
To test fundamental theory related to the evolution of honest signals of quality, our collaborators have successfully transduced genes for these three proteins, CYP2J19, BDH1L, and TTC39B, into chicken fibroblast cells to induce the production of astaxanthin (red pigment). My work will compare observations from these chicken cells to patterns of expression of CYP2J19, BDH1L, and TTC39B in the follicles of Northern Cardinals (Cardinalis cardinalis) under different environmental conditions such as exposing wild-caught birds to cage stress. I will also further investigate the differences in gene expression between male and female cardinals since they have sexually dimorphic coloration.
Featured image (c) Clarence Stewart
'Omics in the Anthropocene 