ssette. (B) Southern-blot analysis of genomic DNA from wild-type (+/+), heterozygous (+/−), and homozygous (−/−) mice. DNA fragments corresponding to wild-type (4.5 kb) and the targeted (5.5 kb) alleles are illustrated. (C) Western blot analysis of Sam68 expression. Protein extracts from wild-type, heterozygous, and homozygous cells subjected to immunoblot analyses using normal rabbit serum, anti-Sam68 AD1 antibody, the peptide antibody AD1 preabsorbed with the immunogenic peptide corresponding to amino acids 330–348 of mouse Sam68, anti-Sam68 Sc333 antibody that recognizes the C-terminal 20 amino acids of Sam68, and anti-actin antibodies as loading control. The migration of the molecular mass markers is known on the left in kDa. Table 1 Proge