MPK-1 diphosphorylation signals were detected at the late pachytene region, which is in the middle of the gonad, and also in maturing oocytes in wild-type worms, wild type worms subjected to
cul-5 RNAi, and
cul-2 homozygotes. On the other hand, diphosphorylation-specific signals did not appear in
cul-2 homozygotes depleted of
cul-5, whereas signals specific to unphosphorylated MPK-1 were observed. As well, diphosphorylation-specific signals did not appear in
cul-5 null mutant depleted of
cul-2.