EMSA on CAGGTG binding protein. (A) Each CAGGTG and AAGGTG motif present in Ei and 3′E of the transgenes was assayed for protein binding. Nuclear lysates from DT40 CL18 cells were used. (B) EMSA in the presence of antibodies. 15 µg of nuclear extract and 1 µg anti-E47 or IgG control antibodies were used. EMSA assays were repeated at least three times.