Cooperative action between L-Maf and Sox2 on delta-crystallin gene expression during chick lens development

Mech Dev. 2003 Apr;120(4):455-65. doi: 10.1016/s0925-4773(03)00002-9.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Chick Embryo
  • DNA-Binding Proteins / metabolism
  • DNA-Binding Proteins / physiology*
  • Ectoderm / metabolism
  • Electroporation
  • Eye Proteins
  • Gene Expression Regulation, Developmental*
  • HMGB Proteins
  • Homeodomain Proteins / biosynthesis
  • Lens, Crystalline / embryology*
  • Maf Transcription Factors
  • Models, Genetic
  • Nerve Tissue Proteins / biosynthesis
  • Nuclear Proteins / metabolism
  • Nuclear Proteins / physiology*
  • PAX6 Transcription Factor
  • Paired Box Transcription Factors
  • Plasmids / metabolism
  • Protein Structure, Tertiary
  • RNA, Messenger / metabolism
  • Repressor Proteins
  • SOXB1 Transcription Factors
  • Transcription Factors / metabolism
  • Transcription Factors / physiology*
  • Transcriptional Activation
  • Tumor Suppressor Proteins
  • delta-Crystallins / biosynthesis*


  • DNA-Binding Proteins
  • Eye Proteins
  • HMGB Proteins
  • Homeodomain Proteins
  • L-MAF protein, Gallus gallus
  • Maf Transcription Factors
  • Nerve Tissue Proteins
  • Nuclear Proteins
  • PAX6 Transcription Factor
  • Paired Box Transcription Factors
  • RNA, Messenger
  • Repressor Proteins
  • SOXB1 Transcription Factors
  • Sine oculis homeobox homolog 3 protein
  • Transcription Factors
  • Tumor Suppressor Proteins
  • delta-Crystallins
  • prospero-related homeobox 1 protein