Meeting Abstract
Male anoles form stable dominant-subordinate dyads when paired together under conditions of limited resources. After acquisition of their respective social status, dominants and subordinates show distinct behavioral profiles including quantitative differences in aggression and courtship as well as distinct endocrine patterns including changes in testosterone and catecholamine levels. Such widespread changes suggest that acquisition and maintenance of social status is accompanied by a change in the metabolic state as well. Hence, we evaluated differences in energy storage after acquisition of social status by measuring skeletal muscle glycogen levels and whole body fat level. Skeletal muscle tissue was obtained from size and weight matched male anoles paired for 11 days. Glycogen levels were then quantified by hydrolysis into glucose followed by colorimetric quantification of glucose levels. Muscle glycogen content was higher in established dominants relative to subordinates (paired t test: t=2.504, p= 0.0336) . Body composition was measured in live animals before and after pairing (9 days) using EchoMRITM, which utilizes nuclear magnetic resonance to distinguish body fat from lean mass. Dominants were found to have higher levels of body fat relative to subordinates (t=2.235, p= 0.042) after but not before pairing. Thus, changes in body fat levels accompany changes in social status. The difference in social status is also correlated with differences in muscle glycogen levels, but our results cannot determine whether this difference exists before pairing or acquired as a result of social status acquisition.
