Loss-of-function mutation in DNAH8 induces asthenoteratospermia associated with multiple morphological abnormalities...

Area of Science:

• Reproductive biology
• Human genetics
• Molecular biology

Background:

• Asthenozoospermia, characterized by reduced sperm motility and abnormal morphology, is a frequent cause of male infertility.
• Multiple morphological abnormalities of the sperm flagella (MMAF) is a primary contributor to asthenozoospermia, yet its genetic basis remains partially unexplained.
• Existing identified MMAF-associated genes do not account for all human cases.

Purpose of the Study:

• To investigate the genetic underpinnings of asthenozoospermia in patients with MMAF.
• To identify novel genes implicated in sperm flagellar formation and function.
• To establish the etiological role of DNAH8 mutations in human male infertility.

Main Methods:

• Genetic analysis of an asthenozoospermia patient presenting with MMAF.
• Loss-of-function mutation screening for DNAH8.
• Immunofluorescence staining and Western blotting to assess DNAH8 expression levels.
• Sperm morphology and motility analysis.

Main Results:

• A loss-of-function mutation in the DNAH8 gene was identified in the asthenozoospermia patient with MMAF.
• The identified mutation was confirmed to negatively impact DNAH8 expression.
• This study provides the first evidence linking DNAH8 to human MMAF.
• DNAH8 is demonstrated to be crucial for proper sperm flagellar development.

Conclusions:

• Loss-of-function mutations in DNAH8 are a cause of male infertility associated with MMAF.
• DNAH8 plays an essential role in the formation and function of the sperm flagellum.
• This discovery expands the known genetic causes of male infertility and MMAF.