The Genetic Defects of N-DRC in Male Infertility.

The nexin-dynein regulatory complex (N-DRC) is a large protein complex composed of at least 11 subunits (DRC1-DRC11) and plays a crucial role in ciliary and flagellar motility. It links adjacent doublets of microtubules (DMTs) between A and B microtubules, regulating dynein motor activity. Genetic defects in N-DRC subunits lead to primary ciliary dyskinesia (PCD) and abnormal flagellar motility. In recent years, an increasing number of genetic mutations in N-DRC subunits have been reported, associated with male infertility, characterized by multiple morphological abnormalities of the flagella (MMAF) and asthenozoospermia. Therefore, genetic diagnosis of N-DRC defects in male infertility is of significant clinical importance, impacting the reproductive health of patients and the well-being of their offspring. In this review, we summarize the gene mutations of N-DRC subunits reported in the literature concerning male infertility, analyze the phenotypes of affected patients, and outline the functions and mechanisms of N-DRC in sperm flagellar motility. Furthermore, we provide an overview of gene knockout (KO) mouse models of N-DRC and their associated phenotypes. Finally, we summarize the outcomes of assisted reproductive technology (ART) in both patients and KO mice, offering references for the diagnosis and treatment of clinical male infertility caused by N-DRC genetic factors.