title: A comprehensive evolutionary analysis based on nucleotide and amino acid sequences of the alpha- and beta-subunits of glycoprotein hormone gene family.
abstract: On the basis of nucleotide sequences of the coding region and their predicted amino acid sequences, 58 glycoprotein hormone subunit genes were compared, aligned and used to construct phylogenetic trees for this family. The analysis included 17 alpha-subunits, eight TSH beta-, six FSH beta-, 17 LH beta/CG beta-, four fish gonadotropin (GTH)-I beta-, five fish GTH-II beta- and one additional fish GTH beta-subunit. The reliability of the phylogenetic trees was probed with the bootstrapping test. Our results indicated that: both the alpha- and beta-subunits of the family diverged from a common ancestral gene about 927 million years ago, the initial precursor of the beta-subunit duplicated to give rise to the LH beta and a second hormone, the latter then duplicating to FSH beta and TSH beta, so that FSH beta is related more to TSH beta than to LH beta; and bony fish GTH-I beta is highly related to mammalian FSH beta, whereas the bony fish GTH-II beta is more related to mammalian LH beta. For scientific consistency and convenience, we propose that the following nomenclature be adopted, all fish gonadotropins of type I be classified as FSH and all type II be classified as LH hormones. In addition, on the basis of results from this and other studies, we propose an evolutionary history for this glycoprotein hormone family. Reconstruction of the evolutionary history of this family would not only provide clues to understanding thyrotropin and gonadotropin functions, but would also allow further revision of the present nomenclature of the gonadotropins in fish.
authors.affiliation: US Department of Agriculture, Agricultural Research Service, Roman L Hruska US Meat Animal Research Center, Clay Center, Nebraska 68933, USA.
authors.forename: M D
authors.initials: MD
authors.lastname: Li
authors.forename: J J
authors.initials: JJ
authors.lastname: Ford
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D018997:Chorionic Gonadotropin, beta Subunit, Human / Q000235:genetics; D019143:Evolution, Molecular; D005399:Fishes / Q000235:genetics; D005640:Follicle Stimulating Hormone / Q000235:genetics; D037201:Follicle Stimulating Hormone, beta Subunit; D015292:Glycoprotein Hormones, alpha Subunit / Q000235:genetics*; D006065:Gonadotropins, Pituitary / Q000235:genetics; D006736:Horses; D006801:Humans; D007986:Luteinizing Hormone / Q000235:genetics; D008969:Molecular Sequence Data; D010215:Papio; D010802:Phylogeny; D016415:Sequence Alignment; D012756:Sheep; D013552:Swine; D013972:Thyrotropin / Q000235:genetics
chemical_list: D018997:Chorionic Gonadotropin, beta Subunit, Human; D037201:Follicle Stimulating Hormone, beta Subunit; D015292:Glycoprotein Hormones, alpha Subunit; D006065:Gonadotropins, Pituitary; C057763:gonadotropin- pituitary, beta-subunit I, salmon; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin