Practice question

LIN-12 Notch controls binary decision between anchor cell and ventral uterine precursor within gonad. During L2 stage, Z1.ppp and Z4.aaa express both LAG-2 ligand and LIN-12 receptor. Lateral interaction amplifies slight difference so cell with higher LIN-12 becomes ventral uterine precursor continuing division, while other with lower LIN-12 becomes anchor cell. Gain-of-function lin-12 mutants with constitutively active NICD cause both Z1.ppp and Z4.aaa to adopt ventral uterine fate, producing two ventral uteri, loss of anchor cell, extra uterine tissue and failure to induce vulva. Thus excess LIN-12 activity leads to duplication of uterine lineage at expense of AC.