Title:
Reprogramming in yeast

KOBAYASHI, Takehiko (National Institute of Genetics/Sokedai)

Abstract:
　The genes encoding ribosomal RNA, called rDNA, are the most abundant in the eukaryotic genome.  They reside in tandem repetitive structure, in some cases totaling hundreds of copies.  Due to the repetitive structure, the rDNA copies are easily lost by recombination among the repeats.  A unique gene amplification system in the rDNA compensates for the losses.  Then the copy number of rDNA is repeating up and down and the rDNA becomes one of the most fragile regions in the genome.  As genome instability is known to induce cellular senescence, the rDNA plays a central role for the induction. We recently found that the instability is recovered when the cell is “reprogrammed” in the yeast daughter cell that corresponds to a stem cell in mammal.

References:
Kobayashi, T. Ribosomal RNA gene repeats, their stability and cellular senescence . Proc Japan Acad. Series B, 90119-129, 2014

Saka, K., Ide, S., Ganley, A.R., and Kobayashi, T. Cellular senescence in yeast is regulated by rDNA noncoding transcription.　Curr Biol. 23:1794-1798, 2013

Ide, S., Miyazaki, T., Maki, H., Kobayashi, T. Abundance of ribosomal RNA gene copies maintains genome integrity. Science 327, 693-696, 2010

Kobayashi. T. Ganley, A. R. D. Recombination regulation by transcription-induced cohesin dissociation in rDNA repeats. Science, 309, 1581-1584, 2005.

Kobayashi, T., Horiuchi, T., Tongaonkar, P., Vu, L., Nomura, M. SIR2 regulates recombination between different rDNA repeats, but not recombination within individual rRNA genes in yeast. Cell, 117, 441-453, 2004

小林武彦企画　特集「ヒトゲノム中98％の“未踏領域” 非コードDNAに挑む」実験医学　2012年9月号