Explaining inter-lab variance in C. elegans N2 lifespan: Making a case for standardized reporting to enhance...

Area of Science:

• Biogerontology
• Model Organism Research
• Developmental Biology

Background:

• The nematode Caenorhabditis elegans (C. elegans) is a key model for aging studies.
• The wild-type N2 strain shows significant lifespan variability across labs.
• This variability impedes inter-laboratory data comparability and reproducibility.

Purpose of the Study:

• To investigate the causes of significant C. elegans N2 lifespan variation between laboratories.
• To identify experimental factors contributing to discrepancies in lifespan data.
• To propose solutions for enhancing the reliability of C. elegans lifespan studies.

Main Methods:

• Meta-analysis of over 1000 published C. elegans N2 lifespan assays.
• Assessment of methodological metadata alongside lifespan data.
• Statistical analysis to correlate experimental conditions with lifespan outcomes.

Main Results:

• Observed mean N2 lifespans ranging from 7 to over 35 days across studies.
• Identified temperature and the sterilizer 5-fluoro-2'-deoxyuridine (FUDR) as factors influencing lifespan.
• Noted lifespan differences correlated with geographic origin of experiments.
• Found that cumulative minor experimental variations, not single critical factors, likely cause discrepancies.

Conclusions:

• Numerous subtle differences in experimental design and handling contribute to C. elegans N2 lifespan variability.
• Lack of standardized methods and insufficient reporting hinder inter-lab comparability.
• Establishment of a reporting standard is proposed to improve C. elegans lifespan study reliability and reproducibility.