Two differing precursor genes for the salmon-type gonadotropin-releasing hormone exist in salmonids

ABSTRACT Salmon gonadotropin-releasing hormone (sGnRH) is considered to have an important role in the control of reproduction in salmonid fish. As a basis for understanding the physiological functioning of sGnRH at the molecular level, we characterized the nucleotide sequences of two types of cDNAs...

Full description

Bibliographic Details
Published in:Journal of Molecular Endocrinology
Main Authors: Ashihara, M, Suzuki, M, Kubokawa, K, Yoshiura, Y, Kobayashi, M, Urano, A, Aida, K
Format: Article in Journal/Newspaper
Language:unknown
Published: Bioscientifica 1995
Subjects:
Endocrinology
Molecular Biology
Sockeye
Atlantic salmon
Salmo salar
Online Access:http://dx.doi.org/10.1677/jme.0.0150001
https://jme.bioscientifica.com/view/journals/jme/15/1/jme_15_1_001.xml
https://jme.bioscientifica.com/downloadpdf/journals/jme/15/1/jme_15_1_001.xml
Description
Summary:ABSTRACT Salmon gonadotropin-releasing hormone (sGnRH) is considered to have an important role in the control of reproduction in salmonid fish. As a basis for understanding the physiological functioning of sGnRH at the molecular level, we characterized the nucleotide sequences of two types of cDNAs encoding the precursors of sGnRH in sockeye salmon (ss), Oncorhynchus nerka , by a cloning strategy based on reverse transcription-PCR. The two types of cDNAs are referred to as ss-pro-sGnRH-I and -II, and consisted of 435 and 481 bases respectively. Both precursors are predicted to contain a signal peptide, the hormone and a GnRH-associated peptide that is attached to the hormone via a Gly-Lys-Arg sequence. The presence of two types of mRNAs hybridizing with either cDNA was confirmed by Northern blot analysis of brain RNA from sockeye salmon, masu salmon, O. masou , and rainbow trout, O. mykiss . The ss-pro-sGnRH-I cDNA had 97·2% and 82·8% overall identity with sGnRH cDNA from masu salmon and putative sGnRH cDNA deduced from the gene of the Atlantic salmon, Salmo salar respectively, whereas the ss-pro-sGnRH-II cDNA had 80·0% and 91·2% overall identity with the former and the latter respectively. The nucleotide sequences of ss-sGnRH-I and -II cDNAs showed less similarity (79·3%). These results indicated that each salmonid species possesses two differing sGnRH genes. The results of Southern blot analysis using genomic DNA extracted from individuals support this evidence in sockeye salmon, masu salmon and rainbow trout.

Similar Items