A cDNA encoding two point mutations in the FOG repression motif (asparagine 3 to alanine and lysine 5 to alanine), which disrupt the interaction of the protein with subunits of the nucleosome remodeling and histone deacetylase complex, and a floxed neo cassette within intron 1, was inserted by homologous recombination. The neo cassette was removed by cre-mediated recombination. Western blot analysis in bone marrow cell lysates from homozygous mice confirmed expression of the mutant protein at levels similar to those of the wild-type protein. (J:156475)