63.2 Saturday, Jan. 5 Control of animal growth: Where are we and where do we go from here? SHERIDAN, M.A.; North Dakota St. Univ. email@example.com
Since the description of the secretotropic action of growth hormone (GH) and the emergence of the “dual effector theory” of growth control in mammals, the study of non-mammalian model organisms, particularly teleost fish, has advanced our understanding of how organismal growth is regulated. In particular, the unique structures of the pituitary and the endocrine pancreas (Brockmann body) of teleosts have lent themselves to the study of GH and pancreatic hormone secretion (e.g., insulin, somatostatins), and the interaction of these hormones in growth control. Teleosts also have provided novel insight into peripheral modulation of GH and insulin-like growth factor (IGF) sensitivity as well as of GH and IGF action. As a result of teleosts having undergone a genome duplication event during their evolution (ca. 320 MYA), they possess multiple genes encoding major elements of the growth control system (GH receptors, IGF receptors, etc.), which provides a unique opportunity to examine the functional significance of duplicated genes. Moreover, teleosts provide an opportunity to examine the molecular basis of GH multi-functionality and to resolve its anabolic (growth promoting) and catabolic (lipolytic) actions.