The Polycomb-group homolog Bmi-1 is a regulator of murine Hox gene expression

Mech Dev. 1996 Aug;58(1-2):153-64. doi: 10.1016/s0925-4773(96)00570-9.


Drosophila homeotic genes and vertebrate Hox genes are involved in the anteroposterior organization of the developing embryo. In Drosophila, the Polycomb- and trithorax-group genes are required to maintain the homeotic genes throughout development in the repressed or activated state, respectively. The murine Bmi-1 proto-oncogene was shown to exhibit homology to the Polycomb-group gene Posteior sex combs. Mice lacking the Bmi-1 gene revealed posterior transformations along the axial skeleton, whereas transgenic mice overexpressing Bmi-1 display anterior transformations. We have analysed the expression patterns of several Hox genes by RNA in situ hybridization on serial sections of 11.5- and 12.5-day Bmi-1 null mutant embryos. Furthermore, we have analysed the expression of a Hoxc-8/LacZ fusion gene in younger embryos. Our analyses show that Bmi-1 is involved in the repression of a subset of Hox genes from different clusters from at least day 9.5 onwards. We discuss the possibility that members of the murine Polycomb-group can form multimeric protein complexes of different compositions with varying affinity or specificity for different subsets of Hox genes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Animals
  • Embryo, Mammalian / chemistry
  • Gene Expression Regulation*
  • Genes, Homeobox / physiology*
  • In Situ Hybridization
  • Mice
  • Mice, Inbred Strains
  • Morphogenesis / drug effects
  • Mutation
  • Nuclear Proteins / metabolism*
  • Nuclear Proteins / pharmacology
  • Nuclear Proteins / physiology*
  • Polycomb Repressive Complex 1
  • Proto-Oncogene Proteins / metabolism*
  • Proto-Oncogene Proteins / pharmacology
  • Proto-Oncogene Proteins / physiology*
  • RNA / analysis
  • Repressor Proteins*
  • Tissue Distribution


  • Bmi1 protein, mouse
  • Nuclear Proteins
  • Proto-Oncogene Proteins
  • Repressor Proteins
  • RNA
  • Polycomb Repressive Complex 1