Helen Lamb, McKenzi Fernholz, Małgorzata J Liro, Krista M Myles, Holly Anderson, Lesilee S Rose
{"title":"The Rac1 homolog CED-10 is a component of the MES-1/SRC-1 pathway for asymmetric division of the C. elegans EMS blastomere.","authors":"Helen Lamb, McKenzi Fernholz, Małgorzata J Liro, Krista M Myles, Holly Anderson, Lesilee S Rose","doi":"10.1093/genetics/iyaf020","DOIUrl":null,"url":null,"abstract":"<p><p>Asymmetric cell division is essential for the creation of cell types with different identities and functions. The EMS blastomere of the four-cell Caenorhabditis elegans embryo undergoes an asymmetric division in response to partially redundant signaling pathways. One pathway involves a Wnt signal from the neighboring P2 cell, while the other pathway is defined by the receptor-like MES-1 transmembrane protein localized at the EMS-P2 cell contact, and the cytoplasmic kinase SRC-1. In response to these signals, the EMS nuclear-centrosome complex rotates so that the spindle forms on the anterior-posterior axis; after division, the daughter cell contacting P2 becomes the endodermal precursor cell. Here we identify the Rac1 homolog CED-10 as a new component of the MES-1/SRC-1 pathway. Loss of CED-10 affects both spindle positioning and endoderm specification in the EMS cell. SRC-1 dependent phosphorylation at the EMS-P2 contact is reduced. However, the asymmetric division of the P2 cell, which is also MES-1 and SRC-1 dependent, appears normal in ced-10 mutants. These and other results suggest that CED-10 acts upstream of, or at the level of, SRC-1 activity in the EMS cell. In addition, we find that the branched actin regulator ARX-2 is enriched at the EMS-P2 cell contact site, in a CED-10 dependent manner. Loss of ARX-2 results in EMS spindle orientation defects, suggesting that CED-10 acts through branched actin to promote spindle orientation in the EMS cell.</p>","PeriodicalId":48925,"journal":{"name":"Genetics","volume":" ","pages":""},"PeriodicalIF":3.3000,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Genetics","FirstCategoryId":"99","ListUrlMain":"https://doi.org/10.1093/genetics/iyaf020","RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GENETICS & HEREDITY","Score":null,"Total":0}
引用次数: 0
Abstract
Asymmetric cell division is essential for the creation of cell types with different identities and functions. The EMS blastomere of the four-cell Caenorhabditis elegans embryo undergoes an asymmetric division in response to partially redundant signaling pathways. One pathway involves a Wnt signal from the neighboring P2 cell, while the other pathway is defined by the receptor-like MES-1 transmembrane protein localized at the EMS-P2 cell contact, and the cytoplasmic kinase SRC-1. In response to these signals, the EMS nuclear-centrosome complex rotates so that the spindle forms on the anterior-posterior axis; after division, the daughter cell contacting P2 becomes the endodermal precursor cell. Here we identify the Rac1 homolog CED-10 as a new component of the MES-1/SRC-1 pathway. Loss of CED-10 affects both spindle positioning and endoderm specification in the EMS cell. SRC-1 dependent phosphorylation at the EMS-P2 contact is reduced. However, the asymmetric division of the P2 cell, which is also MES-1 and SRC-1 dependent, appears normal in ced-10 mutants. These and other results suggest that CED-10 acts upstream of, or at the level of, SRC-1 activity in the EMS cell. In addition, we find that the branched actin regulator ARX-2 is enriched at the EMS-P2 cell contact site, in a CED-10 dependent manner. Loss of ARX-2 results in EMS spindle orientation defects, suggesting that CED-10 acts through branched actin to promote spindle orientation in the EMS cell.
期刊介绍:
GENETICS is published by the Genetics Society of America, a scholarly society that seeks to deepen our understanding of the living world by advancing our understanding of genetics. Since 1916, GENETICS has published high-quality, original research presenting novel findings bearing on genetics and genomics. The journal publishes empirical studies of organisms ranging from microbes to humans, as well as theoretical work.
While it has an illustrious history, GENETICS has changed along with the communities it serves: it is not your mentor''s journal.
The editors make decisions quickly – in around 30 days – without sacrificing the excellence and scholarship for which the journal has long been known. GENETICS is a peer reviewed, peer-edited journal, with an international reach and increasing visibility and impact. All editorial decisions are made through collaboration of at least two editors who are practicing scientists.
GENETICS is constantly innovating: expanded types of content include Reviews, Commentary (current issues of interest to geneticists), Perspectives (historical), Primers (to introduce primary literature into the classroom), Toolbox Reviews, plus YeastBook, FlyBook, and WormBook (coming spring 2016). For particularly time-sensitive results, we publish Communications. As part of our mission to serve our communities, we''ve published thematic collections, including Genomic Selection, Multiparental Populations, Mouse Collaborative Cross, and the Genetics of Sex.