Influences of LIN-12/Notch and POP-1/TCF on the Robustness of Ventral Uterine Cell Fate Specification in Caenorhabditis elegans Gonadogenesis

The prospective ventral uterus of the hermaphrodite gonad primordium consists of two pairs of sister cells, with each pair consisting of a proximal cell and a distal cell. All four cells initially are competent to become the anchor cell (AC), a unique cell type that acts as the organizer of subsequent uterine and vulval development. However, the cells soon lose this competence and always become ventral uterine precursor cells (VUs), whereas the cells maintain their AC competence longer, until lin-12/Notch-mediated interactions between them specify one as the AC and the other as a VU. Here, we investigate this asymmetry in developmental potential and VU fate specification between the and sister cells. We find evidence that lin-12 activity contributes to the robustness of VU fate at elevated temperature, that the Caenorhabditis elegans Notch paralog glp-1 is not functionally redundant with lin-12 in specifying VU fate, and that the activity of POP-1, the sole C. elegans TCF ortholog, influences VU fate. We propose a model for how Wnt and LIN-12/Notch signaling together lead to robust specification of the VU fate.