DNAH14 deficiency disrupts sperm annulus positioning and compromises offspring postnatal development

Does DNAH14 deficiency impair sperm flagellar integrity and contribute to male infertility?

Loss of DNAH14 leads to disrupted sperm annulus positioning, defective mitochondrial assembly, reduced sperm motility, and impaired male fertility in both humans and mice.

Pathogenic variants in several axonemal dynein heavy chain (DNAH) genes have been implicated in male infertility and primary ciliary dyskinesia. DNAH14 remains the only member whose roles are undefined.

Genetic analysis was performed on two unrelated Han Chinese infertile men. Functional studies were carried out in a CRISPR-Cas9 Dnah14 knockout (KO) mouse model, with phenotyping of males and their offspring.

Whole-exome sequencing was applied to patient samples. Dnah14 KO mice were generated to assess reproductive phenotypes. Sperm morphology and motility were analyzed using Papanicolaou staining, scanning electron microscopy (SEM), transmission electron microscopy (TEM), immunofluorescence staining, and computer-assisted sperm analysis (CASA). Intracytoplasmic sperm injection (ICSI) was performed in both patients and KO mice, and offspring survival and growth were monitored.

Biallelic DNAH14 variants were identified in two men with asthenoteratozoospermia. Patient HX-042 carried compound heterozygous variants c.1055T>C and c.9788T>C, whereas Patient HX-137 harbored compound heterozygous variants c.10434G>T and c.12512A>G. In both cases, sperm exhibited markedly reduced motility, disrupted annulus positioning and mitochondrial disorganization. DNAH14 was specifically localized to the midpiece of both human and mouse sperm. Dnah14 KO mice exhibited subfertility, characterized by reduced sperm motility, sperm mitochondrial sheath anomaly, annulus mislocalization, and midpiece bending, whereas ciliogenesis in non-reproductive tissues remained unaffected. ICSI achieved normal fertilization and embryonic development in both patients and KO mice. Offspring of KO males exhibited reduced survival and growth retardation.

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We have, for the first time, established genotype and phenotype associations of DNAH14/Dnah14 in humans and mice; however, mechanistic studies remain limited. Further in vivo investigations using animal models are necessary to elucidate the molecular mechanisms by which DNAH14 regulates the structural integrity of sperm flagella. In addition, potential epigenetic mechanisms underlying the role of DNAH14 in postnatal growth also warrant further clarification.

These findings identify DNAH14 as a novel contributor to sperm flagellar architecture and male fertility, expanding the genetic spectrum of DNAH-related disorders. In particular, we identified a critical role of DNAH14 in the precise positioning of the sperm annulus, and further found that DNAH14 may regulate offspring growth and development through sperm epigenetic mechanisms, thereby revealing its important biological functions and providing new perspectives for genetic counselling in infertility.

This work was supported by the National Natural Science Foundation of China (82471650), Sichuan Science and Technology Program (2024YFFK0267), and the National Key Research and Development Program of China (2023YFC2706402). The authors declare no conflict of interests.

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