title: Identification of genes expressed in retinal progenitor/stem cell colonies isolated from the ocular ciliary body of adult mice.
abstract: Rare pigmented cells showing retinal stem cell characteristics have been identified in the ocular ciliary body (CB) of adult mammals. In vitro, these cells were reported to clonally proliferate and generate pigmented sphere colonies (PSC) containing multipotent retinal progenitor-like cells. Because these cells may have important clinical applications and because their embryonic origin is unclear, we have analyzed their local environment and gene expression profile. We found that transcription factors Pax6, Six3, and Rx, all involved in early eye morphogenesis, were expressed in the CB of adult mice. By sequencing a PSC cDNA library, we found that PSC expressed at high levels transcripts involved in the control of redox metabolism and cellular proliferation. PSC also expressed the retinal transcription factor Six6, which expression was not detected in the CB epithelium. By in situ hybridization screen, we found that Palmdelphin (Palm), Hmga2, and a novel transcript were expressed in the central nervous system of early embryos. Palm expression delineated the pigmented epithelium of the future CB and the developing myotome. Hmga2 was expressed in the ventricular zone of the telencephalon, the developing retinal ciliary margin and lens. Several genes expressed in PSC were also expressed in the nasal anlagen. Taken together, our study reveals that PSC isolated from the ocular CB express genes involved in the control of embryonic development, retinal identity, redox metabolism, and cellular proliferation.
authors.affiliation: Developmental Biology Laboratory, Maisonneuve-Rosemont Hospital, 5415 Boul. l'Assomption, Montreal, Canada H1T 2M4.
authors.forename: Julie
authors.initials: J
authors.lastname: Lord-Grignon
authors.forename: Mohamed
authors.initials: M
authors.lastname: Abdouh
authors.forename: Gilbert
authors.initials: G
authors.lastname: Bernier
mesh_terms: D000818:Animals; D002924:Ciliary Body / Q000166:cytology* / Q000196:embryology; D004622:Embryo, Mammalian; D005136:Eye Proteins / Q000235:genetics* / Q000378:metabolism*; D018507:Gene Expression Regulation, Developmental; D025743:HMGA2 Protein / Q000378:metabolism; D018398:Homeodomain Proteins / Q000378:metabolism; D008565:Membrane Proteins / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D051739:Microphthalmia-Associated Transcription Factor / Q000378:metabolism; D009419:Nerve Tissue Proteins / Q000378:metabolism; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000378:metabolism; D012097:Repressor Proteins / Q000378:metabolism; D012160:Retina / Q000166:cytology* / Q000196:embryology; D013234:Stem Cells / Q000378:metabolism*; D015534:Trans-Activators / Q000378:metabolism; D000097607:Homeobox Protein SIX3
chemical_list: D005136:Eye Proteins; D025743:HMGA2 Protein; D018398:Homeodomain Proteins; D008565:Membrane Proteins; D051739:Microphthalmia-Associated Transcription Factor; D009419:Nerve Tissue Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012097:Repressor Proteins; D015534:Trans-Activators; D000097607:Homeobox Protein SIX3; C497235:Mitf protein, mouse; C434124:Palmd protein, mouse; C000605732:Pax6 protein, mouse; C501274:Rx protein, mouse; C114419:Six6 protein, mouse