Transcriptional and spatiotemporal regulation of the dauer program

Abstract

Caenorhabditis elegans can enter a diapause stage called "dauer" when it senses that the environment is not suitable for development. This implies a detour from the typical developmental trajectory and requires a tight control of the developmental clock and a massive tissue remodeling. In the last decades, core components of the signaling pathways that govern the dauer development decision have been identified, but the tissues where they function for the acquisition of dauer-specific traits are still under intense study. Growing evidence demonstrates that these pathways engage in complex cross-talk and feedback loops. In this review, we summarize the current knowledge regarding the transcriptional regulation of the dauer program and the relevant tissues for its achievement. A better understanding of this process will provide insight on how developmental plasticity is achieved and how development decisions are under a robust regulation to ensure an all-or-nothing response. Furthermore, this developmental decision can also serve as a simplified model for relevant developmental disorders.Abbreviations: AID Auxin Induced Degron DA dafachronic acid Daf-c dauer formation constitutive Daf-d dauer formation defective DTC Distal Tip Cells ECM modified extracellular matrix GPCRs G protein-coupled receptors IIS insulin/IGF-1 signaling ILPs insulin-like peptides LBD Ligand Binding Domain PDL4 Post Dauer L4 TGF-β transforming growth factor beta WT wild-type.

Keywords: LoF loss of function.

Figure 1.

Continuous development trajectory (blue arrows) and dauer trajectory (red arrows). the asterisk (*) shows the reproductive development commitment, which can be reached by 3 different paths.

Figure 2.

Overview of the three dauer pathways. Insulin/IGF-1 signaling (DAF-2), TGF-β (DAF-7) and steroid hormone (DAF-12). In bold: transcription factors and co-factors. ILPs: insulin-like peptides.

Figure 3.

DAF-12 and DAF-16 functions in the Execution step of the dauer program. Dashed lines involve inter-organ communication while continuous lines represent tissue autonomous signaling. Created with BioRender.Com.