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Defining wild-type life span in Caenorhabditis elegans
1Department of Biology, University College London, England. dgems@galton.ucl.ac.uk
Summary
Laboratory strains of the nematode Caenorhabdphaebdotis elegans show significant variation in lifespan due to spontaneous mutations. The longest-lived N2 variant likely represents the authentic wild type, crucial for accurate research.
Area of Science:
- Genetics and Genomics
- Developmental Biology
- Aging Research
Background:
- Laboratory populations of Caenorhabditis elegans (C. elegans) become homozygous due to self-fertilization.
- Spontaneous mutations can accumulate in laboratory stocks, especially if they confer no selective disadvantage.
- Lifespan and fertility are potentially mutable traits in C. elegans.
Purpose of the Study:
- To determine the authentic wild-type lifespan of C. elegans N2.
- To identify variations in lifespan among different N2 laboratory strains.
- To investigate the genetic basis of lifespan variation in C. elegans.
Main Methods:
- Comparison of adult median lifespan across six independently maintained N2 wild-type lines at 20°C.
- Cross-comparison of N2 hermaphrodite lifespan with seven wild C. elegans isolates.
- Analysis of F1 progeny lifespan from crosses between N2 variants to assess trait heritability.
Main Results:
- Four N2 variants exhibited median lifespans ranging from 12.0 to 17.0 days; two shortest-lived strains also showed reduced fertility.
- Wild C. elegans isolates' lifespans matched only the longest-lived N2 strain.
- Short lifespans were recessive in F1 progeny, suggesting loss-of-function mutations.
Conclusions:
- Significant lifespan variation exists among C. elegans N2 laboratory strains.
- The longest-lived N2 variant is inferred to be closest to the original wild type.
- The N2 male stock from the Caenorhabditis Genetics Center represents the authentic wild type.