Meeting Abstract

P1.33  Wednesday, Jan. 4  Evolutionary Origin and Divergence of the Growth Hormone/Prolactin/Somtolactin Receptor Family: Insights from Studies in Sea Lamprey ELLENS, E.R.*; KITTILSON, J.D.; SOWER, S.A.; SHERIDAN, M.A.; North Dakota St. Univ., Fargo

In this study, we sought to clarify the evolutionary origin and divergence of the growth hormone receptor (GHR)/prolactin receptor (PRLR)/somatolactin receptor (SLR) family by identifying the ancestral precursor(s) from the liver of sea lamprey, one of the extant groups of the oldest lineage of vertebrates, Agnatha. By using a multi-phased PCR-based approach, we isolated, cloned, and sequenced a single full-length cDNA that encodes a protein that shares amino acid identity with GHRs, PRLRs, and SLRs previously characterized from teleost fish. Expression of the GHR/PRLR/SLR-like transcript was widespread among tissues of the lamprey, including brain, pituitary, heart, liver, and skeletal muscle, which is consistent with the broad physiological roles of GH-family peptides. Phylogenetic analysis suggests that the sea lamprey GHR/PRLR/SLR mRNA derives from an ancestral gene that diverged to give rise to distinct GHRs, PRLRs, and SLRs over the course vertebrate evolution. (Supported by NSF grant IOS09200116 to M.A.S. and IOS0849569 to S.A.S.)