GRD-1/PTR-11, the C. elegans hedgehog/patched-like morphogen-receptor pair, modulates developmental rate

Both hedgehog (Hh) and target of rapamycin complex 2 (TORC2) are central, evolutionarily conserved signaling pathways that regulate development and metabolism. In C. elegans, loss of the essential TORC2 component RICTOR (rict-1) causes delayed development, shortened lifespan, reduced brood, small size and increased fat. Here, we report that knockdown of both the hedgehog-related morphogen grd-1 and its patched-related receptor ptr-11 rescues delayed development in TORC2 loss-of-function mutants, and grd-1 and ptr-11 overexpression delays wild-type development to a similar level to that in TORC2 loss-of-function animals. These findings potentially indicate an unexpected role for grd-1 and ptr-11 in slowing developmental rate downstream of a nutrient-sensing pathway. Furthermore, we implicate the chronic stress transcription factor pqm-1 as a key transcriptional effector in this slowing of whole-organism growth by grd-1 and ptr-11. We propose that TORC2, grd-1 and ptr-11 may act linearly or converge on pqm-1 to delay organismal development.