In both
par-1 and
par-3 mutants the asymmetric distribution of SPAT-1 was lost. In
par-1(
zu310) and
par-2(RNAi) embryos SPAT-1 levels were equal in AB and P1 and as low as in AB in wild type. In
par-3(
it71) SPAT-1 levels were also symmetric but high in both AB and P1 as in P1 in wild type. Therefore, both the asymmetry and the cytoplasmic levels of SPAT-1 depend on PAR proteins.