mom-4(
ne1539);
lit-1(
t1512) embryos were shifted to the restrictive temperature just before the cleavage of the SMDD/AIY mother. In shifted mutant embryos
ttx-3 is expressed in the SMDD/AIY mother and in both SMDD and AIY just after cleavage as in wild-type embryos. However,
ttx-3 expression fails to be maintained in AIY during elongation and larval stage. Removal of
mom-4 and
lit-1 activities just before the cleavage of the ABpl/rpapaa neuroblast leads to the ectopic activation of
ttx-3 (which is normally restricted to the anterior SMDD/AIY mother) in the SIAD/SIBV lineage.