Practice question

Vulval precursor cells demonstrate regulative ability. Normally P5.p-P7.p generate vulva, but if three central VPCs ablated by laser during early L3 before induction, neighboring P3.p, P4.p or P8.p which would normally fuse to hyp7 can be recruited. They possess latent competence sustained by LIN-39 and Wnt signals, and when anchor cell LIN-3 gradient shifts to them, activate LET-23 Ras-MAPK cascade converting to vulval fates, forming functional though sometimes reduced vulva. This regulative compensation illustrates conditional specification within equivalence group, where cell-cell interactions compensate for loss, ensuring robustness of organogenesis despite perturbations during larval development.