|Lynn, Scott - UNIVERSITY OF KY|
|Shepherd, Brian - UNIVERSITY OF KY|
Submitted to: Book of Abstracts Aquaculture America
Publication Type: Abstract Only
Publication Acceptance Date: September 1, 2003
Publication Date: February 21, 2003
Citation: Lynn, S.L., Weber, G.M., Shepherd, B.S. 2003. Complementary dna cloning and expression studies for prolactin, growth hormone, somatolactin and igf-i in yellow perch perca flavescens. [abstract]. Book of Abstracts Aquaculture America. p. 162A Technical Abstract: In several species of teleost, 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 (e.g., salinity, photoperiod & temperature). Plasma insulin-like growth factors (IGFs), which are primarily produced by the liver, act as regulators of the above pituitary hormones and mediate their metabolic and osmoregulatory actions. In the Great Lakes region, yellow perch (Perca flavescens) is an important species both ecologically and economically. Being able to study the expression of the above genes in yellow perch, will provide a better understanding of the developmental, growth and reproductive roles of these hormones between males and females of this species. Thusly, we are presently examining the tissue- and gender-specificity of gene expression for PRL, GH, SL and IGF-I. Using reverse transcription-PCR and molecular cloning, the cDNA sequences of the PRL, SL, and IGF-I genes were determined in yellow perch (GH cDNA was a gift from Dr. F.W. Goetz). Total RNA was purified and first strand cDNAs were produced using 5' RACE techniques from pituitary (PRL, GH, SL) and liver (IGF-I) 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. Cells were grown on LB agar with kanamycin to select for transformants and then specific clones were chosen, screened and grown in culture for plasmid isolation. 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 neoteleost sequences, this codon encodes for the amino acid isoleucine at position 64.