Reciprocal Asymmetry of SYS-1/beta-catenin and POP-1/TCF Controls Asymmetric Divisions in Caenorhabditis Elegans
Overview
Affiliations
beta-Catenins are conserved regulators of metazoan development that function with TCF DNA-binding proteins to activate transcription. In Caenorhabditis elegans, SYS-1/beta-catenin and POP-1/TCF regulate several asymmetric divisions, including that of the somatic gonadal precursor cell (SGP). In the distal but not the proximal SGP daughter, SYS-1/beta-catenin and POP-1/TCF transcriptionally activate ceh-22 to specify the distal fate. Here, we investigate the distribution of SYS-1/beta-catenin and its regulation. Using a rescuing transgene, VNS::SYS-1, which fuses VENUS fluorescent protein to SYS-1, we find more VNS::SYS-1 in distal than proximal SGP daughters, a phenomenon we call "SYS-1 asymmetry." In addition, SYS-1 asymmetry is seen in many other tissues, consistent with the idea that SYS-1 regulates asymmetric divisions broadly during C. elegans development. In particular, SYS-1 is more abundant in E than MS, and SYS-1 is critical for the endodermal fate. In all cases, SYS-1 is reciprocal to POP-1 asymmetry: cells with higher SYS-1 have lower POP-1, and vice versa. SYS-1 asymmetry is controlled posttranslationally and relies on frizzled and dishevelled homologs, which also control POP-1 asymmetry. Therefore, upstream regulators modulate the SYS-1 to POP-1 ratio by increasing SYS-1 and decreasing POP-1 within the same cell. By contrast, SYS-1 asymmetry does not rely on WRM-1, which appears specialized for POP-1 asymmetry. We suggest a two-pronged pathway for control of SYS-1:POP-1, which can robustly accomplish differential gene expression in daughters of an asymmetric cell division.
A transphyletic study of metazoan β-catenin protein complexes.
Mbogo I, Kawano C, Nakamura R, Tsuchiya Y, Villar-Briones A, Hirao Y Zoological Lett. 2024; 10(1):20.
PMID: 39623505 PMC: 11613877. DOI: 10.1186/s40851-024-00243-y.
Rautela U, Sarkar G, Chaudhary A, Chatterjee D, Rosh M, Arimbasseri A PLoS Genet. 2024; 20(11):e1011453.
PMID: 39546504 PMC: 11602045. DOI: 10.1371/journal.pgen.1011453.
Distinct functions of three Wnt proteins control mirror-symmetric organogenesis in the gonad.
So S, Asakawa M, Sawa H Elife. 2024; 13.
PMID: 39485276 PMC: 11620738. DOI: 10.7554/eLife.103035.
Medwig-Kinney T, Kinney B, Martinez M, Yee C, Sirota S, Mullarkey A Elife. 2023; 12.
PMID: 38038410 PMC: 10691804. DOI: 10.7554/eLife.84355.
Mechanisms of lineage specification in Caenorhabditis elegans.
Liu J, Murray J Genetics. 2023; 225(4).
PMID: 37847877 PMC: 11491538. DOI: 10.1093/genetics/iyad174.