Heterochromatin Integrity Affects Chromosome Reorganization After Centromere Dysfunction
Kojiro Ishii,1*
Yuki Ogiyama,1*
Yuji Chikashige,2
Saeko Soejima,1
Fumie Masuda,1
Tatsuyuki Kakuma,3
Yasushi Hiraoka,2,4
Kohta Takahashi1
The centromere is essential for the inheritance of genetic information on eukaryotic chromosomes. Epigenetic regulation of centromere identity has been implicated in genome stability, karyotype evolution, and speciation. However, little is known regarding the manner in which centromere dysfunction affects the chromosomal architectures. Here we show that in the fission yeast Schizosaccharomyces pombe, the conditional deletion of the centromere produces survivors that carry either a neocentromere-acquired chromosome at the subtelomeric region or an acentric chromosome rescued by intertelomere fusion with either of the remaining chromosomes. The ratio of neocentromere formation to telomere fusion is considerably decreased by the inactivation of genes involved in RNA interference–dependent heterochromatin formation. By affecting the modes of chromosomal reorganization, the genomic distribution of heterochromatin may influence the fate of karyotype evolution.
1 Division of Cell Biology, Institute of Life Science, Kurume University, Japan.
2 Kobe Advanced Information and Communications Technology Research Center, National Institute of Information and Communications Technology, Japan.
3 The Biostatistics Center, Kurume University, Japan.
4 Graduate School of Frontier Biosciences, Osaka University, Japan.
* These authors contributed equally to this work.
To whom correspondence should be addressed. E-mail: takahash{at}lsi.kurume-u.ac.jp
