title: Melanotropin and corticotropin are encoded on two distinct genes in the lamprey, the earliest evolved extant vertebrate.
abstract: In the lamprey, which is a member of the oldest extant class of vertebrates, the agnathans, melanotropins (MSH) and corticotropin (ACTH) were found to be encoded on two distinct genes. In all other vertebrates, a single precursor gene, proopiomelanocortin (POMC), encodes MSH and ACTH, as well as beta-endorphin (END). Two different cDNAs were cloned from a lamprey pituitary lambda gt11 cDNA library using antisera against lamprey MSH-B and ACTH(1-16). One cDNA encoded MSH-B, MSH-A and beta-END, while the other cDNA encoded nasohypophysial factor (NHF), ACTH and a different beta-END, but not MSH-A and MSH-B. Northern blot analysis demonstrated that in the adult lamprey pituitary, genes for MSH and ACTH are expressed in the pars intermedia (PI) and pars distalis (PD), respectively.
authors.affiliation: Laboratory of Molecular Endocrinology, School of Fisheries Sciences, Kitasato University, Iwate, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Takahashi
authors.forename: Y
authors.initials: Y
authors.lastname: Amemiya
authors.forename: M
authors.initials: M
authors.lastname: Sarashi
authors.forename: S A
authors.initials: SA
authors.lastname: Sower
authors.forename: H
authors.initials: H
authors.lastname: Kawauchi
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000737:chemistry / Q000235:genetics*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D007798:Lampreys / Q000235:genetics*; D009074:Melanocyte-Stimulating Hormones / Q000737:chemistry / Q000235:genetics*; D008969:Molecular Sequence Data; D010902:Pituitary Gland / Q000737:chemistry / Q000378:metabolism; D011333:Pro-Opiomelanocortin / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis; D014018:Tissue Distribution; D001615:beta-Endorphin / Q000737:chemistry / Q000235:genetics
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D001615:beta-Endorphin; D011333:Pro-Opiomelanocortin; D000324:Adrenocorticotropic Hormone; D009074:Melanocyte-Stimulating Hormones