期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1989
卷号：86
期号：22
页码：8645-8649
DOI：10.1073/pnas.86.22.8645
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：cDNAs encoding alpha and beta subunits of salmon gonadotropins, sGTHI and sGTHII, have been isolated from the cDNA library prepared from salmon pituitary mRNA. sGTHI alpha, sGTHI beta, and sGTHII beta cDNAs encode polypeptides of 114, 137, and 142 amino acids, including signal peptides of 22, 24, and 23 amino acids, respectively. The deduced amino acid sequence for sGTHI alpha revealed rather high homology (66-69%) to mammalian alpha chains, whereas sGTHI beta and sGTHII beta show lower homology (30%) to each other and to mammalian beta subunits. The existence of two distinct beta-subunit cDNAs in the teleost suggests that divergence of the GTH gene took place earlier than divergence of teleosts from the main line of evolution leading to tetrapods.
