Investigation of testis proteome alterations associated with male infertility in Dcaf17-deficient mice

Disruption of Dcaf17 in mice resulted in male infertility with severe spermatogenesis defects. To investigate the molecular basis of infertility phenotype, we examined testicular proteomes of wild-type (WT) and Dcaf17^-/- mice using a mass spectrometry-based approach. We identified 727 and 525 differentially expressed proteins (DEPs) in 3- and 8-week old testes of Dcaf17^-/- mice, respectively, with an adjusted p-value cut-off of ≤ 0.05. Among these, 299 and 298 DEPs had fold change of ≥ 1.5 between WT and Dcaf17^-/- testes at ­3- and 8-week old, respectively. In the 3-week old Dcaf17^-/- testes, 59.5% of the DEPs were up-regulated, while 40.5% were down-regulated. Similarly, in the 8-week old Dcaf17^-/- testes, 83.9% and 16.1% DEPs were up-regulated and down-regulated, respectively. Functional annotation and network analyses highlighted that many DEPs were associated with key biological processes, including ubiquitination, RNA processing, translation, protein folding, protein stabilization, metabolic processes, oxidation-reduction processes and sper­matogenesis. Subsequent immunohistochemistry and immunoblotting analyses showed higher ubiquitin levels in Dcaf17^-/- testes compared to WT, suggesting potential impairment in ubiquitin proteasome system (UPS) due to DCAF17 loss of function. Our data provide a basis for further work to elucidate the molecular function(s) of DCAF17 in spermatogenesis and male fertility.