RNA polymerase II CTD S2P is dispensable during embryogenesis but regulates the developmental diapause in C. elegans [ChIP-seq]

We show that inactivating CDK-12 or expressing a full-length CTD S2A mutant in Caenorhabditis elegans results in developmental arrest at the L1 stage,which mimicks the diapause induced when hatching occurs in the absence of food. Transcriptomic analyses indicate that when CDK-12 is inhibited, only a subset of growth-related genes is not properly expressed. These genes correspond to SL2 trans-spliced mRNAs located in position 2 and over within operons. We show that CDK-12 is required for maximal occupancy of CstF (cleavage stimulatory factor) required for SL2 trans-splicing. The addition of food to developmentally arrested worms leads to an increase of both CTD S2P and SL2 trans-splicing. We propose that CTD S2P functions as a gene-specific signaling mark ensuring the nutritional control of C. elegans development. Overall design: ChIP-seq in CDK12-as strain, in presence of absence of CDK12-as inhibitor, for L1-arrested C.elegans cells recovering from starvation