Transcriptional profiling of Caenorhabditis elegans nematodes treated with L4440 (Empty Vector - EV) or grd-1 RNAi from L1 hatch, and collected at L3 of development.

Hedgehog morphogen GRD-1 regulates C. elegans growth and metabolism downstream of TOR complex 2. Both Hedgehog (Hh) signaling and target of rapamycin complex 2 (TORC2) are evolutionarily conserved pathways that regulate growth and metabolism. In C. elegans, loss of Hh morphogens often leads to developmental arrest, while loss of essential TORC2 component RICTOR (rict-1) causes delayed development, reduced brood, small size, increased fat, and shortened lifespan. Here we report that knockdown of Hh-related morphogen grd-1 causes developmental acceleration rather than arrest by speeding up molting transitions. Further, we show that RNAi to grd-1 not only suppresses the slow growth of rict-1 mutants, but also normalizes multiple abnormalities downstream of TORC2 including restoration of lifespan to near normal and partial rescue of low brood, small body size, and increased fat. Mechanistically, grd-1 slows growth downstream of TORC2 at least in part by increasing transcription of paraquat mediator 1 (PQM-1) target genes. Given the important role of TORC2 in governance of development, these data implicate grd-1 and pqm-1 as critical executors of organismal growth slowing in response to unfavorable growth conditions downstream of the nutrient sensor TORC2 in C. elegans. Three independent passages of wildtype N2 animals were bleach synchronized and grown from larval stage 1 (L1) of development to larval stage 3 (L3) of development on three independently grown RNAi cultures of HT115 E. coli bacteria expressing L4440 (Empty Vector - EV Control) or grd-1 dsRNA to induce RNAi knockdown. Animals were collected via manual inspection at the L3 stage, and snap frozen for lysis, RNA extraction and downstream mRNA sequencing analysis. This experiment contains 3 control and 3 grd-1 knockdown replicates, for a total of 6 samples.