Meeting Abstract

77.6  Friday, Jan. 7  Does form dictates function in the adaptive regulation of intestinal performance among snakes? SECOR, Stephen M.*; LIGNOT, Jean-Herve; University of Alabama; Université Montpellier ssecor@biology.as.ua.edu

Snakes exhibit a distinct dichotomy in the regulation of intestinal function. Frequently feeding species maintain intestinal nutrient transport between feeding bouts, whereas infrequently feeders downregulate intestinal function upon the completion of digestion and then rapidly upregulate function with feeding. The cellular mechanisms responsible for these two different intestinal responses apparently lies with the extent that intestinal surface area is modulated with feeding and fasting. For infrequently feeding pythons, the up and downregulation of intestinal function is generated by matched changes in surface area stemming from the respective lengthening and shortening of the microvilli. For frequently feeding colubrid snakes, the lack of any postprandial changes in microvillus length underlies their modest function responses. As we investigate the adaptive interplay between feeding habits and intestinal physiology of snakes, we are examining whether the modulation of microvillus length, or the lack of, are shared traits of these digestive responses that have evolved independent for snakes. As a case example, most boas are sit-and-wait infrequent feeders that widely regulate intestinal function with each meal. And like pythons they experience corresponding changes in microvillus length. In contrast, the Amazon tree boa (Corallus hortulanus) is an arboreal frequent feeder that experience modest regulation of intestinal function and microvillus length, responses that mirror those of the frequently feeding colubrids. Targeted by selection and the pressures to optimize energy expenditure has been the cellular and molecular processes (e.g., gene expression changes, protein trafficking, and actin polymerization) that maintain or modulate enterocyte form and thus function.