Kobayashi M, Kato Y, Yoshiura Y, Aida K
Department of Aquatic Bioscience, University of Tokyo, Japan.
Gen Comp Endocrinol. 1997 Mar;105(3):372-8. doi: 10.1006/gcen.1996.6840.
Two types of cDNA encoding the alpha subunit of pituitary gonadotropin (GTH) were cloned by polymerase chain reaction (PCR) for goldfish pituitary cDNA library. The goldfish GTH-alpha subunit cDNAs, designated as alpha 1 and alpha 2, encode 117 and 118 amino acids, respectively, including a 23-amino-acid signal peptide. These two types of cDNAs showed high homology in nucleotide and amino acid sequence, but deletion of a triplet nucleotides was present in alpha 1. Deduced amino acid sequences represented differences in four residues between alpha 1 and alpha 2 subunits. Analyses of goldfish genomic DNA revealed that each individual goldfish possesses two distinct genes relevant to GTH-alpha 1 and -alpha 2 subunits. Results of reverse transcriptase-PCR analysis suggest that these two GTH-alpha subunit genes are expressed at different levels without relation to sex and gonadal maturity.
通过聚合酶链反应（PCR）从金鱼脑垂体cDNA文库中克隆出两种编码垂体促性腺激素（GTH）α亚基的cDNA。金鱼GTH-α亚基cDNA分别命名为α1和α2，分别编码117和118个氨基酸，包括一个23个氨基酸的信号肽。这两种类型的cDNA在核苷酸和氨基酸序列上具有高度同源性，但α1中存在一个三联体核苷酸缺失。推导的氨基酸序列显示α1和α2亚基之间有四个残基不同。金鱼基因组DNA分析表明，每条金鱼都拥有与GTH-α1和-α2亚基相关的两个不同基因。逆转录酶-PCR分析结果表明，这两个GTH-α亚基基因的表达水平不同，与性别和性腺成熟无关。
