title: Characterization of the genomic and transcriptional structure of the CRX gene: substantial differences between human and mouse.
abstract: We have previously shown that there is a temporal difference in human CRX: gene expression compared with that of mouse Crx. We have now characterized these genes at the genomic and transcriptional levels and here we expand on this earlier report. Human CRX: spans 25 kb and has six exons, and mouse CRX: spans 15 kb and has four exons. We isolated seven human and two mouse mRNAs generated by alternative splicing of a variable 5' untranslated region. The human and mouse genes share an evolutionarily conserved promoter, which contains OTX/CRX type and SP1/AP2 binding sites and drives expression of two conserved transcripts in both species. Additionally, the human gene has a second human-specific promoter, which has OTX/CRX type binding sites and drives expression of five other transcripts. Band shift assays have shown that six of the seven candidate OTX/CRX elements bind CRX in vitro, possibly implying that the gene can regulate its own expression. These data may account for the differences in temporal expression
  we have previously reported between these two species.
authors.affiliation: Section of Cell and Molecular Biology, Faculty of Medicine, Imperial College, London, SW7 2AZ, UK.
authors.forename: Matthew D
authors.initials: MD
authors.lastname: Hodges
authors.forename: Helena
authors.initials: H
authors.lastname: Vieira
authors.forename: Kevin
authors.initials: K
authors.lastname: Gregory-Evans
authors.forename: Cheryl Y
authors.initials: CY
authors.lastname: Gregory-Evans
mesh_terms: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D017398:Alternative Splicing; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D019143:Evolution, Molecular; D018507:Gene Expression Regulation, Developmental; D018398:Homeodomain Proteins / Q000235:genetics*; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic / Q000502:physiology; D012333:RNA, Messenger / Q000378:metabolism; D012160:Retina / Q000196:embryology; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013045:Species Specificity; D015534:Trans-Activators / Q000235:genetics*; D014158:Transcription, Genetic
chemical_list: D020413:3' Untranslated Regions; D020121:5' Untranslated Regions; D018398:Homeodomain Proteins; D012333:RNA, Messenger; D015534:Trans-Activators; C109288:cone rod homeobox protein