Environmental Physiology of Fish
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University of Massachusetts, Amherst, MA, USA
Conte Anadromous Fish Research Center, Turners Falls, MA, USA
The evolution of endocrine function; discovering the hormonal control of osmoregulation in basal vertebrates
The neuroendocrine system is the major mechanism through which changes in the environment are detected and transduced into a coordinated physiological response. Our current understanding of the hormonal control of osmoregulation in aquatic vertebrates comes almost entirely from work on advanced teleosts, in which prolactin (PRL) promotes osmoregulation in freshwater (FW) and growth hormone (GH) promotes osmoregulation in seawater (SW). Lamprey are basal vertebrates and sturgeon are basal bony fishes that share the same osmoregulatory strategy as teleosts and present a unique opportunity to examine the early evolution of the pituitary control of osmoregulation, which to date has been largely unexamined.
Osmoregulatory capacity, and prolactin and growth hormone control over osmoregulation in the vertebrate lineage. Image credit: Stephen McCormick
Our specific aims in this project are to 1) Determine the response of GH and GH receptor to salinity change in lamprey, 2) Determine the osmoregulatory actions of GH in lamprey, and 3) Determine the osmoregulatory roles of GH and PRL in sturgeon. We hypothesize that GH is a SW-acclimating hormone in sea lamprey and that distinct functions of FW acclimation by PRL, and SW-acclimation by GH, will be found in Atlantic sturgeon. By determining for the first time the osmoregulatory function of prolactin and growth hormone in the more basal extant vertebrates, this project will have profound implications for our understanding of endocrinology among all vertebrates including humans. We expect our results to provide evidence of the earliest function of prolactin and growth hormone that can contribute to the revision of physiology and endocrinology textbooks. The results will also have application to the aquaculture and conservation of endangered sturgeon populations and the management of invasive lamprey.
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Publications
Shaughnessy CA, Myhre V, Hall DJ, McCormick SD, Dores RM. 2023. Hypothalamus-pituitary-interrenal (HPI) axis signaling in Atlantic sturgeon (Acipenser oxyrinchus) and sterlet (Acipenser ruthenus). Gen Comp Endo 339:114290.
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Investigators:
Stephen McCormick, USGS Conte Anadromous Fish Research Center, Turners Falls, MA, USA and Departments of Biology and Environmental Conservation, University of Massachusetts, Amherst, MA, USA. mccormick@umext.umass.edu
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Diogo Ferreira-Martins, Researcher, CIIMAR, Interdisciplinary Centre of Marine and Environmental Research, University of Porto, Portugal. dmartins@ciimar.up.pt
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Ciaran Shaughnessy, Assistant Professor of Integrative Physiology, Department of Integrative Biology, Oklahoma State University, Stillwater, OK, USA. ciaran.shaughnessy@okstate.edu
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Mark A. Sheridan, Professor, Department of Biological Sciences, Texas Tech University, Lubbock, TX, USA. mark.sheridan@ttu.edu
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Ningping Gong, Researcher, Texas Tech University, Lubbock, TX, USA. ningping.gong@ttu.edu
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Supported by the National Science Foundation
