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 δ-crystallin expression. Misexpression of L-Maf in the head ectoderm of lens placode-forming embryos by in ovo electroporation induced δ-crystallin only in the region surrounding the lens. To define this restricted expression, we misexpressed L-Maf together with other transcription factors implicated in δ-crystallin expression. Sox2 plus L-Maf expanded the δ-crystallin-inducible domain to the entire head ectoderm and simultaneously increased the quantity of δ-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 δ-crystallin. We also observed that L-Maf and Sox2 cooperatively enhanced the transactivation of a reporter gene bearing the δ-crystallin enhancer in ovo, implying that L-Maf and Sox2 can induce δ-crystallin through the same enhancer. In conclusion, we report here that L-Maf and Sox2 cooperatively regulate the expression of δ-crystallin during chick lens development. © 2003 Elsevier Science Ireland Ltd. All rights reserved.
Shimada, N., Aya-Murata, T., Reza, H. M., & Yasuda, K. (2003). Cooperative action between L-Maf and Sox2 on δ-crystallin gene expression during chick lens development. Mechanisms of Development, 120(4), 455–465. https://doi.org/10.1016/S0925-4773(03)00002-9