DAZL, short for Deleted in Azoospermia-Like, is a germ cell-specific RNA-binding protein. It plays a crucial role in gametogenesis, regulating the translation and localization of specific messenger RNAs (mRNAs) during early development and gametogenesis [2]. It binds to GUU triplets in the 3' untranslated region of target mRNAs and is involved in translational regulation, which is essential for the normal development and function of germ cells [2].

In gene knockout studies, postnatal stage-specific deletion of Dazl in mouse germ cells led to complete male sterility with loss of spermatogonial stem cells, meiotic arrest, and spermatid arrest, while female fertility was not affected. DAZL was found to bind to a large number of testicular mRNA transcripts at the 3'-untranslated region and interact with translation proteins, and its absence led to a decrease in polysome-associated target transcripts and spermatogenic proteins, causing developmental arrest [4]. In DAZL-KO pigs, complete germ cell depletion was observed by 10 weeks old, and after spermatogonial stem cell transplantation, they could support donor-derived spermatogenesis, but with low spermatogenic efficiency [1]. In chicken primordial germ cells (PGCs), loss of DAZL expression led to decreased proliferation and survival, and DAZL was found to control genes related to germline development, pluripotency, and cell proliferation [3].

In conclusion, DAZL is a master regulator essential for spermatogenesis and germ cell survival, as revealed through gene knockout models in mice, pigs, and chickens. Its deletion or dysfunction can lead to male infertility, highlighting its importance in understanding the mechanisms of male reproductive diseases [1,3,4].