FOXJ2 controls meiosis during spermatogenesis in male mice

Spermatogenesis is a highly complex cell differentiation process necessary for production of haploid spermatozoa. Central to this unique process is spermatocyte meiosis. FOXJ2 (Forkhead box J2), a FOX transcription factor, is specifically expressed in meiotic spermatocytes in adult mouse testes, so we used a germ cell specific conditional knockout model (Foxj2(flox/flox) , Mvh-Cre) to explore its role in spermatogenesis. Loss of FOXJ2 in the male germ line led to meiotic arrest and complete infertility. Although, DNA double-strand breaks (DSBs) were initiated, Foxj2-deficient spermatocytes failed to form chromosomal synapses and perform DSB repair. Furthermore, Foxj2-deficient spermatocytes contained significantly less mRNA encoding DSB repair-associated factors (Rad18, Rad51, Brca1, Brca2, and Tex15) and meiotic arrest-related proteins (Fzr1, Hsp70-2, Spata22, Eif4g3, and Zpac); in contrast, no change was observed in the expression of spermatogonia markers (Gfra1, Zbtb16, and c-Kit) and germ cell markers (Dazl, Mvh, and Tra98). Taken together, FOXJ2 appears to promote meiotic progression in male mice by a mechanism that needs further investigation. Mol. Reprod. Dev. 83: 684-691, 2016 © 2016 Wiley Periodicals, Inc.