Submitted to: World Aquaculture Society Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 2/1/2004
Publication Date: 4/2/2004
Citation: Lynn, S.G., Shepherd, B.S. 2004. Cloning and expression studies for multiple endocrine genes in yellow perch perca flavescens. World Aquaculture Society Meeting.
Technical Abstract: In teleosts, the pituitary hormones prolactin (PRL), growth hormone (GH) and somatolactin (SL) show different secretory patterns based on gender and development and can also be influenced by abiotic factors such as salinity, photoperiod and temperature. Plasma insulin-like growth factors (IGFs), which are primarily produced by the liver, are thought to mediate the physiological actions of GH, PRL and SL in teleosts; however, their actions in the yellow perch are, as yet, uncertain. An understanding of the involvement of these genes, and their proteins, in yellow perch growth, development and reproduction will, undoubtedly, aid in efforts to enhance their production in an aquaculture setting. We have generated full-length cDNA sequences of the PRL, SL, IGF-I and '-actin genes in yellow perch (GH cDNA was a gift from Dr. F.W. Goetz), and have partial sequences for both estrogen receptors ('- & '-ER), ghrelin, aromatase and IGF-II. Total RNA was purified and first strand cDNAs were produced using 5' RACE techniques from pituitary (GH, PRL, SL), liver (IGF-I & -II), stomach (ghrelin), brain (aromatase), and gravid ovary ('- & '-ER) tissue. For cloning, primers were developed based upon conserved regions of known teleost sequences and PCR products were cloned into a plasmid and then transferred into competent E. coli cells. Table 1 lists the nucleotide similarities of several other teleosts with the yellow perch PRL, GH, SL, and IGF-I cDNA sequences. Yellow perch PRL appears to have a unique deviation from all other known teleost prolactins such that there is a codon gap associated with bases 190-192. In all but one of other known neo-teleost sequences, this codon encodes for the amino acid isoleucine at position 64. Results on the tissue- and sex-specific expression of these genes, and their potential involvement in yellow perch growth, development and reproduction, will be presented.