title: Two novel odorant receptor families expressed in spermatids undergo 5'-splicing.
abstract: We report the identification of two novel families of odorant receptor (OdR)-like proteins, termed spermatid chemoreceptors (SCRs), in rat spermatids of the testis. The full-length genomic clones encode seven transmembrane domain receptors that share 35-40% identity with certain OdRs and are among the most divergent members of the OdR superfamily based on phylogenetic analysis. RNase protection assays and in situ hybridization studies confirmed the expression of SCRs in spermatids, the post-meiotic, differentiating cell population in the testis. SCR transcripts were undetectable in the prepubertal testis but were readily identified in spermatids of sexually maturing and mature testis. Rapid amplification of cDNA end-polymerase chain reaction and genomic clone sequencing led to the discovery that SCRs are spliced upstream of their presumptive starting methionines. 5'-Splicing of OdRs may regulate the expression of functional chemoreceptors.
authors.affiliation: Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
authors.forename: L D
authors.initials: LD
authors.lastname: Walensky
authors.forename: M
authors.initials: M
authors.lastname: Ruat
authors.forename: R E
authors.initials: RE
authors.lastname: Bakin
authors.forename: S
authors.initials: S
authors.lastname: Blackshaw
authors.forename: G V
authors.initials: GV
authors.lastname: Ronnett
authors.forename: S H
authors.initials: SH
authors.lastname: Snyder
mesh_terms: D017398:Alternative Splicing; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism; D003001:Cloning, Molecular; D017124:Conserved Sequence; D008297:Male; D008969:Molecular Sequence Data; D005810:Multigene Family; D009833:Olfactory Pathways / Q000378:metabolism; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D014176:Protein Biosynthesis; D051381:Rats; D018035:Receptors, Odorant / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry; D012045:Regulatory Sequences, Nucleic Acid; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013087:Spermatids / Q000378:metabolism*; D013737:Testis / Q000378:metabolism*; D014158:Transcription, Genetic
chemical_list: D018035:Receptors, Odorant; D011994:Recombinant Proteins