PORTRAITS
The main goal of my dissertation research is to better understand how some animals produce red coloration from yellow carotenoid pigments they obtain from their food.
I use the marine copepod, Tigriopus californicus, as a model system to understand the physiological constraints on the production of the red carotenoid, astaxanthin. Specifically, I am looking at how mitochondrial function may mediate the bioconversion of dietary precursors to make astaxanthin.
The oxidation reactions necessary for the transformation of yellow dietary carotenoids to red ketocarotenoids are universal. Any animal that consumes yellow carotenoids and turns them into red carotenoids must perform the same suite of reactions. Therefore, the insights gained from experiments on copepod carotenoid metabolism can be extended to other taxa, including birds and other vertebrates.
Carotenoid-based ornaments have been shown to act as signals of individual quality; animals in good condition produce better, more richly-colored ornaments than animals in poorer condition. Insights from correlative studies on carotenoid coloration as signals of quality in birds and other vertebrates have provided a fantastic foundation to our understanding of which traits are signaled by carotenoid ornaments during mate choice. These traits include, immune function, body condition, parasite load, and parental or reproductive performance. Yet, how carotenoid coloration could signal such disparate aspects of individual quality remains unknown.
My dissertation research is motivated by a BIG question in sexual selection and evolutionary biology that has only superficially answered:
What is being signaled from carotenoid ornaments?
