The helicase CHD-7 regulates dauer entry and morphogenesis

LUCIANA F GODOY; DANIEL HOCHBAUM

Congreso; 2nd Latin American Worm Meeting; 2023

Dauers are long-lived larvae specialized in survival and dispersal that areinduced when C. elegans encounters harsh environmental conditions in earlydevelopment. The diapause entry implies an indefinitely delay of reproductivefates and is followed by massive tissue remodeling, constituting a great modelto study phenotypic plasticity. Previously, in a RNAi screen looking for dauersuppressors, we identified the chromodomain helicase CHD-7. Loss of chd-7completely bypass dauer development or fail to complete morphogenesis,resulting in partial dauers (Figure 1A). Epistasis analysis placed CHD-7 in theTGF-b/DAF-7 pathway but also regulating the TGF- b/DBL-1 pathway,functioning as a TGF-b pleiotropic regulator. RNA-seq analysis of partialdauers developed from chd-7 mutants, show 84 DEGs (Differential ExpressedGenes) when compared to normal dauers (Figure 1B). Among them, there ishigh representation of GPCRs (G-protein coupled receptors), collagens andtranscription factors. Because chd-7(gk290); daf-2(e1370) forms partial dauers,we reasoned that among those DEGs we might find genes required for dauerdevelopment/morphogenesis. Thus, we conducted a RNAi-based screen toidentify CHD-7 functional targets using RNAi-hypersensitive strains. In thiswork we present novel candidate genes required for dauer development andmorphogenesis.