title: Cloning and expression of MRG receptors in macaque, mouse, and human.
abstract: Members of the MRG family of G-protein coupled receptors (GPCRs) are expressed predominately in small diameter sensory neurons of the dorsal root ganglia (DRG) suggesting a possible role in nociception. However, the large expansion of this gene family in rodents, combined with the lack of strict rodent orthologs for many of the human MRG genes, limits the usefulness of rodent models to evaluate human MRG involvement in nociception. Furthermore, the high degree of similarity between related rodent Mrg genes suggests that pharmacological approaches to define the function of individual receptors will prove difficult. The creation of an animal model to examine human MRG function will, therefore, require the identification of human MRG orthologs in a non-rodent species. Here we report the identification of MRGD, MRGE, and several MRGX orthologs in the crab-eating macaque, Macaca fascicularis. Similar to their human counterparts, all isolated macaque genes were expressed in dorsal root ganglia neurons. In the case of macaque MrgX2 and MrgD, expression was co-localized with the known nociceptive neuronal markers, IB4, VR1, and SP. Although expression in DRG neurons was the prominent feature of this family, we also found that MrgE was expressed in numerous brain regions of macaque, mouse, and human.
authors.affiliation: Wyeth Research, Functional Genomics Department, 87 Cambridge Park Drive, Cambridge, MA 02140, United States.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhang
authors.forename: Noël
authors.initials: N
authors.lastname: Taylor
authors.forename: Yuhong
authors.initials: Y
authors.lastname: Xie
authors.forename: Roger
authors.initials: R
authors.lastname: Ford
authors.forename: Jeremy
authors.initials: J
authors.lastname: Johnson
authors.forename: Janet E
authors.initials: JE
authors.lastname: Paulsen
authors.forename: Brian
authors.initials: B
authors.lastname: Bates
mesh_terms: D000818:Animals; D015152:Blotting, Northern / Q000379:methods; D015139:Blotting, Southern / Q000379:methods; D001921:Brain / Q000033:anatomy & histology / Q000378:metabolism; D003001:Cloning, Molecular / Q000379:methods; D018076:DNA, Complementary / Q000378:metabolism; D005727:Ganglia, Spinal / Q000166:cytology; D015870:Gene Expression / Q000502:physiology*; D005786:Gene Expression Regulation / Q000502:physiology; D006023:Glycoproteins / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry / Q000379:methods; D017403:In Situ Hybridization / Q000379:methods; D008252:Macaca fascicularis; D051379:Mice; D008969:Molecular Sequence Data; D005810:Multigene Family / Q000235:genetics; D009474:Neurons / Q000378:metabolism*; D012333:RNA, Messenger / Q000096:biosynthesis; D011955:Receptors, Drug / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D016415:Sequence Alignment; D013045:Species Specificity; D013373:Substance P / Q000378:metabolism; D014157:Transcription Factors / Q000145:classification / Q000235:genetics* / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D006023:Glycoproteins; C491669:MORF4L2 protein, human; D012333:RNA, Messenger; D011955:Receptors, Drug; D014157:Transcription Factors; C473590:isolectin B4-binding glycoprotein, mouse; D013373:Substance P