RT Journal Article
SR Electronic
T1 The Grainyhead/LSF transcription factor GRH-1 is rhythmically required for molting
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.03.01.482504
DO 10.1101/2022.03.01.482504
A1 Meeuse, Milou W.M.
A1 Hauser, Yannick P.
A1 Nahar, Smita
A1 Braun, Kathrin
A1 Großhans, Helge
YR 2022
UL http://biorxiv.org/content/early/2022/06/16/2022.03.01.482504.abstract
AB Molting, that is, the synthesis and shedding of a cuticular exoskeleton, is a defining characteristic of ecdysozoa. In nematodes such as C. elegans, molts rhythmically terminate each of four larval stages. The molting cycle is tightly coupled to the rhythmic accumulation of thousands of transcripts. Here, using chromatin immunoprecipitation coupled to sequencing (ChIP-seq) and quantitative reporter assays, we show that these dynamic gene expression patterns rely on rhythmic transcription. To gain insight into the relevant gene regulatory networks (GRNs), we performed an RNAi-based screen for transcription factors required for molting to identify potential components of a molting clock. We find that depletion of GRH-1, BLMP-1, NHR-23, NHR-25, MYRF-1 or BED-3 impairs progression through the molting cycle. We characterize GRH-1, a Grainyhead/LSF transcription factor whose orthologues in other animals are key epithelial cell fate regulators. We show that GRH-1 depletion causes a dose-dependent extension of molt duration, defects in cuticle formation and shedding, and larval death. Coincident with its rhythmic accumulation, GRH-1 is required repetitively for each molt, during specific time windows preceding lethargus. These findings are consistent with a function of GRH-1 in a molting cycle GRN. As its mammalian orthologues, as well as those of BLMP-1 and NHR-23, have been implicated in rhythmic homeostatic skin regeneration in mouse, the mechanisms underlying rhythmic C. elegans molting may apply beyond nematodes.Competing Interest StatementThe authors have declared no competing interest.