Elucidation of functions of telomere-adjacent regions

2017 Fiscal Year Final Research Report

• Project/Area Number: 26290061
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Genome biology
• Research Institution: Osaka University
• Principal Investigator: Kanoh Junko 大阪大学, たんぱく質研究所, 准教授 (10323809)
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: 染色体 / テロメア / サブテロメア

Outline of Final Research Achievements

Functions of subtelomeres, particularly subtelomeric homologous (SH) sequences, remain elusive. Complete removal of SH sequences from the genome revealed that they are dispensable for mitosis, meiosis, and telomere length control. However, SH sequences prevent deleterious inter-chromosomal end fusion by facilitating intra-chromosomal circularization. Surprisingly, SH-deleted cells sometimes survive telomere loss through inter-chromosomal end fusions via homologous loci such as LTRs, accompanied by centromere inactivation of either chromosome. Moreover, SH sequences function as a buffer region against the spreading of subtelomeric heterochromatin into the neighboring gene-rich regions. Furthermore, we found a nucleosome-free region at the subtelomeric border, which may be a second barrier that blocks heterochromatin spreading into the subtelomere-adjacent euchromatin. Thus, our results demonstrate multiple defense functions of subtelomeres in chromosome homeostasis and gene expression.

Free Research Field

分子生物学