a, Schematic illustration of crosses used to probe the specific effects of maternal and paternal epigenetic inheritance on the Mutator-induced sterility (Mis) phenotype. The mut-7(pk204) and mut-16(pk710) alleles both cause global depletion of Mutator 22G RNAs, and can be used interchangeably. Colour code of the small RNAs: Grey – absent. Green – present, without parental influence. Orange – present, with maternal influence. Blue – present, with paternal influence. b-c, Percentage of fertile F1 animals generated by crosses between males and hermaphrodites of indicated genotypes. Fertility implies: presence of paternal (b) or maternal (c) epigenetic inheritance. Sterility implies: no epigenetic inheritance. Statistical significance was tested with a Pearson's Chi-squared test with Yates' continuity correction (NA - not available).