Meeting Abstract
Female Astatotilapia burtoni, a species of mouthbrooding cichlid, voluntarily starve themselves for two weeks while their young develop. Little is known about the physiological mechanisms that have evolved to allow them to accomplish this. A. burtoni therefore represent an excellent animal model in which to study the mechanisms that integrate the regulation of feeding and reproduction. Brooders who are starving face different challenges than starving non-brooders; by comparing brooding and starved females, we aim to identify key evolutionary innovations that allow for mouthbrooding. In addition to the neural regulation of feeding, peripheral changes in physiology are also necessary to allow brooders to conserve energy. Gut cell turnover is an energetically expensive process that is expendable to brooders, who have substantially reduced gut usage for the duration of brooding, in contrast to involuntarily starved females who may resume gut usage at any time. By detecting cell proliferation and apoptosis in the intestines through immunohistochemistry, differences in cell turnover can be compared between starved, brooding, and fed female A. burtoni. Proliferating cells can be quantified using bromodeoxyuridine, a thymidine analog that incorporates into the DNA of new cells. Similarly, apoptosis can be quantified through the TUNEL assay, which labels the ends of fragmented DNA with a unique nucleotide analog. Gut turnover is an excellent starting point to study peripheral adaptations and changes that occur during the brooding period. Potentially a novel evolutionary adaptation for female A. burtoni, gut turnover can allow them to better endure the mouthbrooding process while limiting energetic costs. Further studies could examine cell turnover with higher resolution and throughout the brooding cycle.
