title: Functional second genes generated by retrotransposition of the X-linked ribosomal protein genes.
abstract: We have identified a new class of ribosomal protein (RP) genes that appear to have been retrotransposed from X-linked RP genes. Mammalian ribosomes are composed of four RNA species and 79 different proteins. Unlike RNA constituents, each protein is typically encoded by a single intron- containing gene. Here we describe functional autosomal copies of the X-linked human RP genes, which we designated RPL10L (ribosomal protein L10-like gene), RPL36AL and RPL39L after their progenitors. Because these genes lack introns in their coding regions, they were likely retrotransposed from X-linked genes. The identities between the retrotransposed genes and the original X-linked genes are 89-95% in their nucleotide sequences and 92-99% in their amino acid sequences, respectively. Northern blot and PCR analyses revealed that RPL10L and RPL39L are expressed only in testis, whereas RPL36AL is ubiquitously expressed. Although the role of the autosomal RP genes remains unclear, they may have evolved to compensate for the reduced dosage of X-linked RP genes.
authors.affiliation: Department of Biochemistry, School of Medicine, University of the Ryukyus, 207 Uehara, Nishihara, Okinawa 903-0215, Japan.
authors.forename: Tamayo
authors.initials: T
authors.lastname: Uechi
authors.forename: Noriko
authors.initials: N
authors.lastname: Maeda
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Tanaka
authors.forename: Naoya
authors.initials: N
authors.lastname: Kenmochi
mesh_terms: D024506:5' Flanking Region / Q000235:genetics; D001483:Base Sequence; D015152:Blotting, Northern; D002883:Chromosomes, Human, Pair 14 / Q000235:genetics; D002893:Chromosomes, Human, Pair 3 / Q000235:genetics; D041321:Chromosomes, Human, X / Q000235:genetics*; D004247:DNA / Q000737:chemistry / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D030561:Databases, Nucleic Acid; D005091:Exons; D005260:Female; D018628:Gene Dosage; D020869:Gene Expression Profiling; D005796:Genes / Q000235:genetics; D020131:Genes, Duplicate / Q000235:genetics*; D008040:Genetic Linkage; D006801:Humans; D007438:Introns; D008297:Male; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D021101:Radiation Hybrid Mapping; D018626:Retroelements / Q000235:genetics*; D012269:Ribosomal Proteins / Q000235:genetics*; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid
chemical_list: D018076:DNA, Complementary; C471569:RPL10L protein, human; C471570:RPL36AL protein, human; C471571:RPL39L protein, human; D018626:Retroelements; D012269:Ribosomal Proteins; D004247:DNA