Characterization of PRDM9 Multifunctionality in Yak Testes Through Protein Interaction Mapping

Area of Science:

• Reproductive Biology
• Genetics
• Molecular Biology

Background:

• Meiotic recombination initiates DNA double-strand breaks during spermatogenesis.
• PRDM9 protein is crucial for localizing recombination hotspots in mammals.
• The precise function of PRDM9 in yak spermatogenesis remains largely unknown.

Purpose of the Study:

• To identify PRDM9-interacting proteins and elucidate its novel functions in yak spermatogenesis.
• To investigate the role of PRDM9 in the context of hybrid male sterility.

Main Methods:

• Yeast two-hybrid assays were employed to screen for PRDM9-interacting proteins.
• Next-generation sequencing techniques were utilized for comprehensive screening.
• Gene ontology (GO) analysis was performed on identified interacting proteins.
• Gene expression analysis was conducted in sterile male cattleyak.

Main Results:

• A total of 267 PRDM9-interacting proteins were identified.
• GO analysis highlighted associations with spermatogenesis, homologous recombination repair, RNA splicing, and the ERAD pathway.
• MKX and PDCD5 showed strong interaction with PRDM9 and were expressed in prophase I of meiosis in mice and yaks.
• RNA splicing genes (THOC5, DDX5, XRCC6) were localized in spermatocytes.
• In sterile male cattleyak, 55 out of 58 detected interacting genes were downregulated.

Conclusions:

• A comprehensive PRDM9 interaction network was established.
• A novel function of PRDM9 in spermatogenesis was identified, enhancing understanding of the process.
• The findings offer new perspectives for studying hybrid male sterility in yaks and cattle.