Bacterial Folates Provide an Exogenous Signal for C. elegans Germline Stem Cell Proliferation

Area of Science:

• Developmental Biology
• Cell Biology
• Microbiology

Background:

• Germline stem cells are crucial for reproduction and development.
• Folates (B-complex vitamins) are essential for one-carbon metabolism, impacting amino acid and nucleoside synthesis.
• Exogenous factors influencing germ cell proliferation are not fully understood.

Purpose of the Study:

• To establish an in vitro primary culture system for Caenorhabditis elegans germline stem cells.
• To identify exogenous regulators of germ cell proliferation using this system.
• To investigate the role of folates in modulating germ cell proliferation.

Main Methods:

• Development of an in vitro primary culture system for C. elegans germline stem cells.
• In vitro and in vivo assays to assess the effect of folates on germ cell proliferation.
• Genetic analysis using folate receptor homolog FOLR-1 knockout models.

Main Results:

• A bacterial folate, 10-formyl-tetrahydrofolate-Glun, was identified as a potent stimulator of germ cell proliferation.
• The folate precursor dihydropteroate also enhanced germ cell proliferation, independent of one-carbon metabolism.
• The folate receptor homolog FOLR-1 is essential for mediating the stimulatory effects of these compounds.

Conclusions:

• Bacterial folates, specifically 10-formyl-tetrahydrofolate-Glun, act as exogenous signals to promote germline stem cell proliferation.
• FOLR-1 mediates the response to these bacterial folate compounds.
• This study defines novel roles for folates and related compounds in regulating stem cell behavior.