Ubiquitin homeostasis in the testis is affected in magn mutants. Anti-ubiquitin western blot showing levels of free ubiquitin (arrows) and ubiquitylated proteins in (A) testes, (B) gonadoectomized males (carcasses) and (C) ovaries. Anti-actin provided a loading control. Thirty pairs of testes (A), five male carcasses (B) and ten pairs of ovaries (C) were used as starting material across the different genotypes. Molecular weight markers, from top to bottom: 250, 150, 100, 75, 50, 37, 25, 20, 15 and 10 kDa. Ub, ubiquitin.