Meeting Abstract
Across taxa, chemical signals convey crucial information, such as fitness, social status, and reproductive state. It is well established that several fish species use chemosensory signaling during reproduction, with individuals possessing mechanisms to detect sexually-relevant olfactory signals at a reproductive advantage. In fishes, odorants are detected by one of three main olfactory receptor neuron (ORN) types located in the olfactory epithelium. Crypt cells, an ORN unique to fishes, is hypothesized to function in pheromone detection, and one family of recently described receptors known as vomeronasal-like type 1 receptors, or V1Rs, are hypothesized to bind these sexually-relevant compounds. Here, we tested whether social status and/or reproductive state might influence crypt cell and V1R expression in the olfactory epithelium of highly social African cichlid, Astatotilapia burtoni. Males exist as either dominant (reproductively active) or subordinate (reproductively suppressed), and females cycle between gravid (reproductively receptive) and mouthbrooding parental care states. Using the crypt cell marker s100, we found that gravid, ready to spawn females had more crypt cells in their olfactory epithelium compared to reproductively suppressed brooding females. Similarly, in situ hybridization for one of the six V1Rs in fishes, V1R4, revealed different levels of expression in animals of different reproductive and social status. Since reproduction can be considered the most important event in any animal’s life, gaining insight into the cellular and molecular mechanisms that mediate the detection of sexually relevant stimuli is important in understanding how reproduction is coordinated
