Identification of a novel nonsense mutation on the Pax3 gene in ENU-derived white belly spotting mice and its genetic interaction with c-Kit

Authors

  • Xiao-Li Guo,

    1.  Key Laboratory of Molecular Developmental Biology, Institute of Genetics & Developmental Biology, Chinese Academy of Sciences, Beijing, China
    2.  Graduate School of Chinese Academy of Sciences, Beijing, China
    Search for more papers by this author
  • Hai-Bin Ruan,

    1.  MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, Jiangsu, China
    Search for more papers by this author
  • Yan Li,

    1.  Key Laboratory of Molecular Developmental Biology, Institute of Genetics & Developmental Biology, Chinese Academy of Sciences, Beijing, China
    2.  Graduate School of Chinese Academy of Sciences, Beijing, China
    Search for more papers by this author
  • Xiang Gao,

    1.  MOE Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Nanjing University, Nanjing, Jiangsu, China
    Search for more papers by this author
  • Wei Li

    1.  Key Laboratory of Molecular Developmental Biology, Institute of Genetics & Developmental Biology, Chinese Academy of Sciences, Beijing, China
    Search for more papers by this author

Wei Li, e-mail: wli@genetics.ac.cn

Summary

In the course of a large-scale screening program of N-ethyl-N-nitrosourea mutagenesis, we isolated two semidominant mutation lines with white belly spotting, named as wps and wbs. Direct sequencing detected a nucleotide G-to-A transversion in exon 2 of the c-Kit gene in wps, which resulted in a missense D60N mutation. Another mutant, wbs, was mapped to chromosome 1 by genome-wide linkage analysis. In 93 meioses, the wbs locus was confined to a 5.2-Mb region between D1Mit380 and D1Mit215, including the Pax3 gene. A nonsense mutation K107X on the Pax3 coding region in wbs mice was identified, causing the loss of Pax3 protein in the homozygous mutant. We further demonstrated that Pax3 exhibited genetic interaction with c-Kit by intercrossing the wps and wbs mice. Further, Pax3 transactivated the c-Kit promoter in different cell lines. However, electrophoretic mobility shift assays showed that Pax3 did not bind to the c-Kit promoter, indicating that Pax3 may interact with c-Kit in an indirect way. This expands our understanding of the intricate regulatory network governing the melanocyte development.

Ancillary