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研究発表を行った学会；
・第４０回日本発生生物学会・第５９回日本細胞生物学会　合同大会、2007年 5月28~30日(福岡)

タイトル；Homozygousembryos for gene trap insertion in the RNA polymerase 1-2 gene showed early embryonic lethality.
発表者；　陳　輝　氏
　　　（熊本大学　発生医学研究センター　臓器形成分野）
Abstract；
Ribosomal biogenesis is closely involved in cell growth and proliferation. Ribosomal DNA (rDNA) transcription by RNA polymerase I (Pol I) is an important initial step for production of ribosomes. The RNA polymerase 1-2 (Rpo1-2) gene encodes the second large subunit (1135 aa) of Pol I machinery and is comprised of 15 exons. In a gene trap screen using pU-Hachi vector carrying the IRES-βgeo, we have identified an insertion mutation (Rpo1-2Gt) in the Rpo1-2 gene. The trap vector was inserted into the 14th exon, and a fusion protein containing 823 aa of the N-terminal portion of Rpo1-2 protein and 101 aa derived from the vector sequence was expected to be produced from the fusion transcripts of the Rpo1-2 gene and the trap vector. However, the transcription level of the Rpo1-2Gt trap allele was lower than that of wild allele. Rpo1-2Gt/Gt homozygous embryos were not found at 7.5dpc, and no resorption site was observed in the uteri of heterozygous females mated with heterozygous males. Rpo1-2Gt/Gt embryos at 8-16-cell stage were obtained using in vitro fertilization. These results indicate that homozygous embryos die at around preimplantation stage.