Coiled-coil domain-containing 38 is required for acrosome biogenesis and fibrous sheath assembly in mice

J Genet Genomics. 2024 Apr;51(4):407-418. doi: 10.1016/j.jgg.2023.09.002. Epub 2023 Sep 13.

Abstract

During spermiogenesis, haploid spermatids undergo dramatic morphological changes to form slender sperm flagella and cap-like acrosomes, which are required for successful fertilization. Severe deformities in flagella cause a male infertility syndrome, multiple morphological abnormalities of the flagella (MMAF), while acrosomal hypoplasia in some cases leads to sub-optimal embryonic developmental potential. However, evidence regarding the occurrence of acrosomal hypoplasia in MMAF is limited. Here, we report the generation of base-edited mice knocked out for coiled-coil domain-containing 38 (Ccdc38) via inducing a nonsense mutation and find that the males are infertile. The Ccdc38-KO sperm display acrosomal hypoplasia and typical MMAF phenotypes. We find that the acrosomal membrane is loosely anchored to the nucleus and fibrous sheaths are disorganized in Ccdc38-KO sperm. Further analyses reveal that Ccdc38 knockout causes a decreased level of TEKT3, a protein associated with acrosome biogenesis, in testes and an aberrant distribution of TEKT3 in sperm. We finally show that intracytoplasmic sperm injection overcomes Ccdc38-related infertility. Our study thus reveals a previously unknown role for CCDC38 in acrosome biogenesis and provides additional evidence for the occurrence of acrosomal hypoplasia in MMAF.

Keywords: Acrosomal hypoplasia; Asthenoteratozoospermia; Disease modeling; Infertility; Multiple morphological abnormalities of the flagella (MMAF); Sperm motility.

MeSH terms

  • Acrosome*
  • Animals
  • Male
  • Mice
  • Mutation
  • Semen* / metabolism
  • Sperm Tail / metabolism
  • Spermatogenesis / genetics
  • Spermatozoa