Roles for the RNA polymerase III regulator MAFR-1 in regulating sperm quality in Caenorhabditis elegans

Area of Science:

• Molecular Biology
• Genetics
• Reproductive Biology

Background:

• The negative regulator MAFR-1 influences RNA polymerase III (pol III) transcription, lipid metabolism, and organismal health.
• Previous studies indicated MAFR-1's broad effects, but its specific roles in reproduction were unclear.

Purpose of the Study:

• To investigate the function of MAFR-1 in Caenorhabditis elegans, particularly its role in male fertility.
• To identify novel MAFR-1 interacting proteins and elucidate its mechanism in the male germline.

Main Methods:

• Gene deletion of mafr-1 in C. elegans.
• Yeast two-hybrid assays to identify protein interactors.
• Phenotypic analysis of mafr-1 null mutants, including spermatid morphology and competitive fertilization assays.
• Germline-specific rescue experiments.

Main Results:

• Animals lacking mafr-1 exhibited phenotypes consistent with previous RNA interference (RNAi) studies and revealed a novel sperm-specific function.
• Novel MAFR-1 interactors were identified, enriched in sperm and germline tissues.
• mafr-1 null males produced smaller spermatids with reduced competitive fertilization ability, dependent on RNA pol III activity.
• Germline-specific restoration of MAFR-1 rescued these spermatid defects, indicating a cell-autonomous role.

Conclusions:

• MAFR-1 plays a critical cell-autonomous role in nematode male fertility, specifically in spermatid development and function.
• The findings highlight a conserved role for Maf1 and RNA pol III in male reproductive processes across species, with potential implications for mammalian fertility.