Back to Search
Start Over
Observation of DNA intertwining along authentic budding yeast chromosomes
- Source :
- Genesdevelopment. 31(21)
- Publication Year :
- 2017
-
Abstract
- DNA replication of circular genomes generates physically interlinked or catenated sister DNAs. These are resolved through transient DNA fracture by type II topoisomerases to permit chromosome segregation during cell division. Topoisomerase II is similarly required for linear chromosome segregation, suggesting that linear chromosomes also remain intertwined following DNA replication. Indeed, chromosome resolution defects are a frequent cause of chromosome segregation failure and consequent aneuploidies. When and where intertwines arise and persist along linear chromosomes are not known, owing to the difficulty of demonstrating intertwining of linear DNAs. Here, we used excision of chromosomal regions as circular “loop outs” to convert sister chromatid intertwines into catenated circles. This revealed intertwining at replication termination and cohesin-binding sites, where intertwines are thought to arise and persist but not to a greater extent than elsewhere in the genome. Intertwining appears to spread evenly along chromosomes but is excluded from heterochromatin. We found that intertwines arise before replication termination, suggesting that replication forks rotate during replication elongation to dissipate torsion ahead of the forks. Our approach provides previously inaccessible insight into the topology of eukaryotic chromosomes and illuminates a process critical for successful chromosome segregation.
- Subjects :
- 0301 basic medicine
DNA Replication
Cell division
Heterochromatin
Chromosomal Proteins, Non-Histone
Genetic Structures
Cell Cycle Proteins
Replication Origin
Saccharomyces cerevisiae
Biology
Chromosome segregation
03 medical and health sciences
chemistry.chemical_compound
Chromosome Segregation
Genetics
Sister chromatids
DNA, Fungal
DNA replication
Chromosome
030104 developmental biology
chemistry
Eukaryotic chromosome fine structure
biological phenomena, cell phenomena, and immunity
Chromosomes, Fungal
Genome, Fungal
DNA
Developmental Biology
Research Paper
Subjects
Details
- ISSN :
- 15495477
- Volume :
- 31
- Issue :
- 21
- Database :
- OpenAIRE
- Journal :
- Genesdevelopment
- Accession number :
- edsair.doi.dedup.....61c762b0722e6e121b7d8be1a8179294