Germ cell-specific expression of the novel proteins. Testes from W/Wvmutant mice (A) and a Sertoli cell line, TM4 (B), were subjected to protein extraction and western blot analysis using the specific antibodies. Total proteins from the testes were extracted by boiling the minced tissues in a protein sample buffer containing 3% SDS and 5% β-mercaptoethanol. ADAM2, with spermatogenic cell-specific expression, was included as a control. WT, wild type; TC, testicular (spermatogenic) cells.