RRC ID 19680
Author Shirae-Kurabayashi M, Matsuda K, Nakamura A.
Title Ci-Pem-1 localizes to the nucleus and represses somatic gene transcription in the germline of Ciona intestinalis embryos.
Journal Development
Abstract In many animal embryos, germ-cell formation depends on maternal factors located in the germ plasm. To ensure the development of germ cells, germline progenitors must be prevented from differentiating inappropriately into somatic cells. A common mechanism for this appears to be the active repression of somatic gene transcription. Species-specific germ-plasm components, such as Pgc in Drosophila and PIE-1 in C. elegans, establish germline transcriptional quiescence by inhibiting general transcriptional machineries. In the ascidian Ciona intestinalis, although transcriptional repression in the germline has been proposed, the factors and mechanisms involved have been unknown. We found that the protein products of Ci-pem-1 RNA, which is an ascidian-specific component of the postplasm (the germ plasm equivalent in ascidians), localized to the nucleus of germline blastomeres, as well as to the postplasm. Morpholino oligonucleotide-mediated Ci-pem-1 knockdown resulted in the ectopic expression of several somatic genes that are usually silent in the germline. In the Ci-pem-1 knockdown embryos, the expression of both β-catenin- and GATAa-dependent genes was derepressed in the germline blastomeres, suggesting that Ci-Pem-1 broadly represses germline mRNA transcription. Immunoprecipitation assays showed that Ci-Pem-1 could interact with two C. intestinalis homologs of Groucho, which is a general co-repressor of mRNA transcription. These results suggest that Ci-pem-1 is the C. intestinalis version of a germ-plasm RNA whose protein product represses the transcription of somatic genes during specification of the germ-cell fate, and that this repression may be operated through interactions between Ci-Pem-1 and Groucho co-repressors.
Volume 138(14)
Pages 2871-81
Published 2011-7
DOI 10.1242/dev.058131
PII 138/14/2871
PMID 21693510
MeSH Animals Cell Nucleus / metabolism* Ciona intestinalis / metabolism Ciona intestinalis / physiology* Cloning, Molecular Gene Expression Regulation, Developmental / physiology* Gene Knockdown Techniques Germ Cells / metabolism* Immunohistochemistry Immunoprecipitation In Situ Hybridization Japan Oligonucleotides / genetics Polymerase Chain Reaction Repressor Proteins / genetics Repressor Proteins / metabolism*
IF 5.763
Times Cited 28
C.intestinalis / (O.japonicus)