Meeting Abstract
Bill Karasov and Jared Diamond’s 1988 article ‘Adaptive interplay between physiology and ecology in digestion’ laid the foundation for my exploration in the adaptive interplay between feeding habits and the regulation of digestive performance. This work, largely undertaken with snakes, has identified an adaptive dichotomy for which frequently-feeding species narrowly regulate intestinal function with feeding, whereas species that naturally experience long periods between meals, due to an infrequent feeding behavior or dormancy, up and down regulate intestinal form and function with the start and finish of each meal. Proposed for why such a dichotomy exists resides in the energetic benefits of each mode as a function of feeding frequency. The cellular mechanisms underlying this dichotomy is apparently morphological, dictated by whether luminal surface area does not change with feeding or fasting (due to no change in microvillus length) as exhibited by frequent-feeders, or changes dramatically due to the postprandial lengthening of the microvilli and subsequent shortening following digestion as experienced by infrequent-feeders. Taking advantage of this dichotomy, our comparative approach is allowing us to identified specific gene programs and regulatory pathways responsible for the synthesis, mobilization and insertion of microvillus and membrane proteins involved in the postprandial remodeling of the brushborder membrane for infrequently feeding snakes. Given the convergent evolution of modes of regulatory responses among snakes, we are asking whether the underlying molecular programs of a common phenotypic response (i.e., microvillus lengthening) are conserved or have evolve independently, and thus are unique.
