Fig. 1. Identification of two Rnf17 isoforms. (A) Northern blot analysis of Rnf17 expression. Two Rnf17 transcripts (5.2 kb and 3.5 kb) were detected in the testis. ß-Actin served as a loading control. (B) Schematic diagram of two RNF17 protein isoforms. (C) Western blot analysis of RNF17 proteins. Testicular protein extracts (30 µg) were resolved by SDS-PAGE. Anti-serum 1774 recognized both RNF17L and RNF17S. Anti-serum GP8 was specific to RNF17L. (D) RNF17 is largely cytoplasmic. Cytoplasmic and nuclear fractions of adult testis were prepared and subjected to western blot analysis. MVH (Mouse Vasa homolog) is a cytoplasmic protein control (Toyooka et al., 2000); SYCP3 (synaptonemal complex protein 3) is a nuclear protein control (Chuma and Nakatsuji, 2001); ß-actin served as a loading control. C, cytoplasmic fractions; N, nuclear fractions.