title: Cooperative action between L-Maf and Sox2 on delta-crystallin gene expression during chick lens development.
abstract: Lens development is regulated by a variety of transcription factors with distinct properties. The lens-specific transcription factor, L-Maf, is essential for lens formation and induces lens-specific markers, such as the crystallin genes. In this study, we analyzed the mechanism by which L-Maf regulates delta-crystallin expression. Misexpression of L-Maf in the head ectoderm of lens placode-forming embryos by in ovo electroporation induced delta-crystallin only in the region surrounding the lens. To define this restricted expression, we misexpressed L-Maf together with other transcription factors implicated in delta-crystallin expression. Sox2 plus L-Maf expanded the delta-crystallin-inducible domain to the entire head ectoderm and simultaneously increased the quantity of delta-crystallin mRNA expressed. In contrast, co-expression of L-Maf with other factors such as Pax6, Six3 and Prox1 had little or no effect on delta-crystallin. We also observed that L-Maf and Sox2 cooperatively enhanced the transactivation of a reporter gene bearing the delta-crystallin enhancer in ovo, implying that L-Maf and Sox2 can induce delta-crystallin through the same enhancer. In conclusion, we report here that L-Maf and Sox2 cooperatively regulate the expression of delta-crystallin during chick lens development.
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0101, Japan.
authors.forename: Naoko
authors.initials: N
authors.lastname: Shimada
authors.forename: Tomoko
authors.initials: T
authors.lastname: Aya-Murata
authors.forename: Hasan Mahmud
authors.initials: HM
authors.lastname: Reza
authors.forename: Kunio
authors.initials: K
authors.lastname: Yasuda
mesh_terms: D000818:Animals; D002642:Chick Embryo; D004268:DNA-Binding Proteins / Q000378:metabolism / Q000502:physiology*; D004475:Ectoderm / Q000378:metabolism; D018274:Electroporation; D005136:Eye Proteins; D018507:Gene Expression Regulation, Developmental; D024002:HMGB Proteins; D018398:Homeodomain Proteins / Q000096:biosynthesis; D007908:Lens, Crystalline / Q000196:embryology*; D050977:Maf Transcription Factors; D008957:Models, Genetic; D009419:Nerve Tissue Proteins / Q000096:biosynthesis; D009687:Nuclear Proteins / Q000378:metabolism / Q000502:physiology*; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D010957:Plasmids / Q000378:metabolism; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000378:metabolism; D012097:Repressor Proteins; D055748:SOXB1 Transcription Factors; D014157:Transcription Factors / Q000378:metabolism / Q000502:physiology*; D015533:Transcriptional Activation; D025521:Tumor Suppressor Proteins; D038207:delta-Crystallins / Q000096:biosynthesis*; D000097607:Homeobox Protein SIX3; D000098551:Prospero-Related Homeobox 1 Protein
chemical_list: D004268:DNA-Binding Proteins; D005136:Eye Proteins; D024002:HMGB Proteins; D018398:Homeodomain Proteins; D050977:Maf Transcription Factors; D009419:Nerve Tissue Proteins; D009687:Nuclear Proteins; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; D012333:RNA, Messenger; D012097:Repressor Proteins; D055748:SOXB1 Transcription Factors; D014157:Transcription Factors; D025521:Tumor Suppressor Proteins; D038207:delta-Crystallins; D000097607:Homeobox Protein SIX3; D000098551:Prospero-Related Homeobox 1 Protein; C111440:L-MAF protein, Gallus gallus