MRPG: Investigations on the Role of Calcitonin in Reproduction and Development of the Atlantic Stingray

Calcitonin is a phylogenetically ancient hormone that is produced by the parafollicular C-cells of the thyroid gland in mammals and the ultimobranchial gland of all jawed non-mammalian vertebrates. Despite over 35 years of active research and recent use of calcitonin as a therapeutic drug for osteopathic diseases, little is known about the definitive role of this enigimatic hormone in vertebrate physiology. The present study will characterize the relationships between three processes and calcitonin bioactivity in the Atlantic stingray (Dasyatis sabina), a well-studied elasmobranch species. Along with histologic observations on the activity of the ultimobranchial gland, these indicators of calcitonin bioactivity will be correlated with embryogenic, developmental, and reproductive events in embryonic, neonatal, and reproductively active male and female D. sabina. Preliminary information derived from this Minority Research Planning Study will be used to develop a focused research plan for identifying the definitive role of calcitonin in elasmobranch fishes, the oldest extant vertebrate group to possess this hormonal system.