title: Caenorhabditis elegans SWI/SNF subunits control sequential developmental stages in the somatic gonad.
abstract: The Caenorhabditis elegans somatic gonadal precursors (SGPs) are multipotent progenitors that give rise to all somatic tissues of the adult reproductive system. The hunchback and Ikaros-like gene ehn-3 is expressed specifically in SGPs and is required for their development into differentiated tissues of the somatic gonad. To find novel genes involved in SGP development, we used a weak allele of ehn-3 as the basis for a reverse genetic screen. Feeding RNAi was used to screen ∼2400 clones consisting of transcription factors, signaling components, and chromatin factors. The screen identified five members of the C. elegans SWI/SNF chromatin remodeling complex as genetic enhancers of ehn-3. We characterized alleles of 10 SWI/SNF genes and found that SWI/SNF subunits are required for viability and gonadogenesis. Two conserved SWI/SNF complexes, PBAF and BAF, are defined by their unique array of accessory subunits around a common enzymatic core that includes a catalytic Swi2/Snf2-type ATPase. Tissue-specific RNAi experiments suggest that C. elegans PBAF and BAF complexes control different processes during somatic gonadal development: PBRM-1, a signature subunit of PBAF, is important for normal SGP development, whereas LET-526, the distinguishing subunit of BAF, is required for development of a differentiated cell type, the distal tip cell (DTC). We found that the SWSN-4 ATPase subunit is required for SGP and DTC development. Finally, we provide evidence that C. elegans PBAF subunits and hnd-1/dHand are important for the cell fate decision between SGPs and their differentiated sisters, the head mesodermal cells.
authors.affiliation: Department of Genetics, North Carolina State University, Raleigh, North Carolina 27695-7614.
authors.forename: Edward E
authors.initials: EE
authors.lastname: Large
authors.forename: Laura D
authors.initials: LD
authors.lastname: Mathies
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics / Q000378:metabolism; D017173:Caenorhabditis elegans / Q000235:genetics / Q000378:metabolism*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002868:Chromosomal Proteins, Non-Histone / Q000235:genetics / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism; D006066:Gonads / Q000254:growth & development*; D008648:Mesoderm / Q000378:metabolism; D010641:Phenotype; D034622:RNA Interference; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
chemical_list: D000251:Adenosine Triphosphatases; D051792:Basic Helix-Loop-Helix Proteins; D029742:Caenorhabditis elegans Proteins; D002868:Chromosomal Proteins, Non-Histone; D004268:DNA-Binding Proteins; D014157:Transcription Factors; C492557:EHN-3 protein, C elegans; C516539:HND-1 protein, C elegans; C445179:SWI-SNF-B chromatin-remodeling complex
keywords: C. elegans; SWI/SNF; chromatin remodeling; ehn-3; hnd-1