Meeting Abstract

29.9  Jan. 5  Carotenoid pigments in the tissues of zebra finches (Taeniopygia guttata): identity, distribution, and intercorrelations TOOMEY, M.B.*; MCGRAW, K.J.; Arizona State University, Tempe, AZ; Arizona State University, Tempe, AZ matthew.toomey@asu.edu

Carotenoids serve a variety of functions in animals, including sexually selected coloration, photoprotection, antioxidant activity, and immune function. Carotenoids are distributed throughout the body and are likely to have different functions in different tissues. Carotenoids in the integument serve as sexual signals and photoprotectants, whereas carotenoids in internal fluids and tissues (e.g. plasma, liver, adipose tissue) serve as antioxidants and immunomodulators. Although animals cannot synthesize carotenoids de novo, dietary carotenoids are often metabolized into different forms with specific functions. However, the metabolic precursors and products and the relative allocation of carotenoids among various sites in the body are not well known. To explore these patterns, we used high performance liquid chromatography (HPLC) to identify, quantify, and compare the carotenoid composition of the diet, plasma, liver, adipose tissue, eye, beak, and legs of male and female Zebra Finches (Taeniopygia guttata). In the beak and the eye of both sexes, we identified red ketocarotenoids that are restricted to these tissues, indicating metabolism is occurring at the site of deposition. The concentration of astaxanthin (a ketocarotenoid) in the eye was correlated with plasma zeaxanthin levels, indicating that it may be a precursor for the production of this carotenoid. Analyses are ongoing and we will discuss the allocation of carotenoids among tissues and the functional implication of these patterns.