The transcription factor VAB-23 links vulval cell fate specification and morphogenesis.

During organogenesis, individual cells must commit to and execute specific cell fates. However, the molecular mechanisms linking cell fate specification to fate execution and morphogenesis remain a largely unexplored area in developmental biology. The Caenorhabditis elegans vulva is an excellent model to dissect the molecular pathways linking cell fate specification and execution during organogenesis. We have recently identified a conserved nuclear zinc finger transcription factor called VAB-23 that plays essential roles during vulval torid formation in the larva and ventral epidermal closure in the embryo. VAB-23 regulates the transcription of specific target genes including smp-1 Semaphorin. EGFR/RAS/MAPK signaling upregulates via the HOX protein LIN-39 the expression of VAB-23 in the 1° vulval cell lineage, indicating that cell fate specification and execution are temporally overlapping and tightly linked processes. Here, we discuss the roles of VAB-23 in morphogenesis and the implications of its regulation on the spatio-temporal control of organogenesis.