title: Early pre-implantation lethality in mice carrying truncated mutation in the RNA polymerase 1-2 gene.
abstract: Ribosomal DNA (rDNA) transcription by RNA polymerase I (Pol I) is an important initial step for the production of ribosomes. The RNA polymerase 1-2 (Rpo1-2) gene is comprised of 15 exons and encodes 1135 amino acids (aa) of the second largest subunit in Pol I. In a gene trap screen, we have identified an insertional mutation (Rpo1-2(Gt)) in the 14th exon of Rpo1-2, resulting in a truncation of 312aa from the C-terminal. In Rpo1-2(Gt/Gt) embryos, the synthesis of rRNA was severely impaired. Rpo1-2(Gt/Gt) embryos could develop to the morula stage, and thereafter displayed nucleolus disruption and apoptotic cell death. These results indicate that the loss of rDNA transcription induced nucleolar structure disorganization and apoptosis in preimplantation embryos.
authors.affiliation: Institute of Embryology and Genetics, Kumamoto University, Honjo 2-2-1, Kumamoto 860-0811, Japan.
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.forename: Zhenghua
authors.initials: Z
authors.lastname: Li
authors.forename: Kyoko
authors.initials: K
authors.lastname: Haruna
authors.forename: Zhengzhe
authors.initials: Z
authors.lastname: Li
authors.forename: Zhongzhe
authors.initials: Z
authors.lastname: Li
authors.forename: Kei
authors.initials: K
authors.lastname: Semba
authors.forename: Masatake
authors.initials: M
authors.lastname: Araki
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Yamamura
authors.forename: Kimi
authors.initials: K
authors.lastname: Araki
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000502:physiology*; D020022:Genetic Predisposition to Disease / Q000196:embryology* / Q000235:genetics*; D051379:Mice; D009154:Mutation; D012318:RNA Polymerase I / Q000235:genetics*; D012319:RNA Polymerase II / Q000235:genetics*; D016019:Survival Analysis; D015996:Survival Rate
chemical_list: D012319:RNA Polymerase II; D012318:RNA Polymerase I