title: MRG-1, a mortality factor-related chromodomain protein, is required maternally for primordial germ cells to initiate mitotic proliferation in C. elegans.
abstract: We identified MRG-1, a Caenorhabditis elegans chromodomain-containing protein that is similar to the human mortality factor-related gene 15 product (MRG15). RNA-mediated interference (RNAi) of mrg-1 resulted in complete absence of the germline in both hermaphrodite and male adults. Examination of the expression of PGL-1, a component of P granules, revealed that two primordial germ cells (PGCs) are produced during embryogenesis in mrg-1(RNAi) animals, but these PGCs cannot undergo mitotic proliferation, and they ultimately degenerate during post-embryonic development. Zygotic RNAi experiments using RNAi-deficient hermaphrodites and wild-type males demonstrated that MRG-1 functions maternally. Moreover, immunoblot analysis using mutant animals with germline deficiencies indicated that MRG-1 is synthesized predominantly in oocytes. These results suggest that MRG-1 is required maternally to form normal PGCs with the potential to start mitotic proliferation during post-embryonic development.
authors.affiliation: Department of Life Science, Graduate School of Science and Technology, Kobe University, 1-1 Rokkodaicho, Nadaku, Kobe 657-8501, Japan.
authors.forename: Masaki
authors.initials: M
authors.lastname: Fujita
authors.forename: Teruaki
authors.initials: T
authors.lastname: Takasaki
authors.forename: Noboru
authors.initials: N
authors.lastname: Nakajima
authors.forename: Taizo
authors.initials: T
authors.lastname: Kawano
authors.forename: Yoshiro
authors.initials: Y
authors.lastname: Shimura
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Sakamoto
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D017173:Caenorhabditis elegans / Q000196:embryology* / Q000502:physiology*; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D002455:Cell Division; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000378:metabolism; D004268:DNA-Binding Proteins; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D018507:Gene Expression Regulation, Developmental; D015151:Immunoblotting; D008297:Male; D008938:Mitosis; D008969:Molecular Sequence Data; D009865:Oocytes / Q000378:metabolism; D010641:Phenotype; D012313:RNA / Q000378:metabolism; D012330:RNA, Double-Stranded; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012097:Repressor Proteins; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D014157:Transcription Factors / Q000737:chemistry
chemical_list: C486381:CITED2 protein, human; D029742:Caenorhabditis elegans Proteins; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; C470833:MORF4L1 protein, human; C470832:MRG-1 protein, C elegans; D012330:RNA, Double-Stranded; D011993:Recombinant Fusion Proteins; D012097:Repressor Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D012313:RNA