Figure 1. Natural variation in C. elegans egg retention.
(A) The number of eggs in utero in hermaphrodites (mid-L4 +48 hr) of 316 genetically distinct strains (isotypes) often strongly deviated from values observed in the laboratory strain N2 (~15 eggs in utero). We defined three classes of strains with distinct levels of egg retention: Class I weak:<10 eggs in utero (N=34), Class II canonical: 10–25 eggs in utero (N=230), Class III strong:>25 eggs in utero (N=14). N=18–150 individuals per strain were scored. (B) Geographic distribution of 316 C. elegans wild strains. Strains with different degrees of egg retention are labelled in different colours. For a detailed comparison of geographic distribution of the three phenotypic Classes, see Figure 1—figure supplement 1A. (C) Nomarski microscopy images of adult hermaphrodites (mid-L4 +48 hr) in wild strains with divergent egg retention. Eggs (coloured) contain embryos at different stages of development.