Fig. 2. Cre-mediated deletion of the C-terminus of Brca2 in ES cells. (A) Immunoblotting analysis of whole-cell extract of Brca2Tr/Ex27+ and Brca2Tr/ΔEx27 clonal cell lines immunoprecipated (IP) with anti-myc, anti-Rad51 and N-terminal anti-Brca2 antibodies, and immunoblotted (IB) with the anti-Brca2 antibody. The positions of full-length Brca2, the exon 27-deleted (Brca2ΔEx27) and the exon 11-truncated (Brca2Tr2014) proteins are indicated. (B) Failure of normal induction of Rad51 foci in Brca2Tr/ΔEx27 ES cells. Brca2Tr/Ex27+ and Brca2Tr/ΔEx27 ES cells mock irradiated (left upper and lower panels) or irradiated with 10 Gy (right upper and lower panels) were fixed and analysed by immunofluorescent microscopy. DNA is labelled with DAPI and appears blue. Rad51 was detected with anti-Rad51 antibody and a secondary FITC-conjugated antibody. The right upper panel shows induction of Rad51-containing nuclear foci in Brca2Tr/Ex27+ cells. The right lower panel shows failure of induction of Rad51 foci in Brca2Tr/ΔEx27 ES cells.