title: Conserved physical linkage of GnRH-R and RBM8 in the medaka and human genomes.
abstract: Candidate genes for human type II gonadotropin-releasing hormone receptor (GnRH-RII) reside on two separate loci, 1q12-q21 and 14q21-23, yet neither locus generates functional GnRH-RII. Instead, their opposite DNA strands encode functional RNA-binding motif protein 8 (RBM8s), which is also encoded by another locus, 5q13-q14. To elucidate the mechanism through which such multiple human GnRH-RII/RBM8 loci arose, here we have defined an RBM8 locus in a comparative model species, the medaka Oryzias latipes. The medaka RBM8, which exists as a single copy gene, is linked to, but does not overlap with, GnRH-R2 on linkage group (LG) 16, demonstrating the ancient origin of the physical linkage between GnRH-R and RBM8. The medaka LG 16 contains orthologous segments to the human chromosome 1 and therefore the 1q12-q21 locus would be an originating human GnRH-RII/RBM8 segment. Furthermore, like the human RBM8s on 1q12-q21 and 5q13-q14 but not that on 14q21-q23, the medaka RBM8 is a multiexon gene, indicating that the 14q21-q23 and 5q13-q14 loci were generated by retrotransposition and segmental genomic duplication, respectively, of the originating 1q12-q21 locus.
authors.affiliation: Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo 113-8657, Japan.
authors.forename: Kataaki
authors.initials: K
authors.lastname: Okubo
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Mitani
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Naruse
authors.forename: Mariko
authors.initials: M
authors.lastname: Kondo
authors.forename: Akihiro
authors.initials: A
authors.lastname: Shima
authors.forename: Minoru
authors.initials: M
authors.lastname: Tanaka
authors.forename: Katsumi
authors.initials: K
authors.lastname: Aida
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D002878:Chromosomes, Human, Pair 1; D002883:Chromosomes, Human, Pair 14; D002895:Chromosomes, Human, Pair 5; D017124:Conserved Sequence; D017931:DNA Primers; D008040:Genetic Linkage; D005819:Genetic Markers; D016678:Genome; D015894:Genome, Human; D006801:Humans; D008969:Molecular Sequence Data; D009990:Oryzias / Q000235:genetics*; D016601:RNA-Binding Proteins / Q000235:genetics*; D011966:Receptors, LHRH / Q000235:genetics*; D012261:Ribonucleoproteins / Q000235:genetics
chemical_list: D017931:DNA Primers; D005819:Genetic Markers; C406243:RBM8A protein, human; D016601:RNA-Binding Proteins; D011966:Receptors, LHRH; D012261:Ribonucleoproteins