ena-STUDY-INSTITUT PASTEUR-18-02-2015-13:41:42:660-54
Using centrifugal elutriation and deep sequencing, we identified early and late replication fork origins, genomewide of Candida glabrata
Candida glabrata, like Saccharomyces cerevisiae, belongs to the Saccharomycetaceae yeasts that underwent whole-genome duplication. Here, using centrifugal elutriation and deep sequencing, we identified early and late replication fork origins, genomewide. Centromeres, HML and HMR loci and most histone genes are replicated early, whereas natural chromosomal breakpoints are located in late replicating regions. An ARS capture experiment allowed to identify 181 Autonomous Replication Sequences (ARS), and their relative fitness was determined during a growth competition experiment. Analysis of ARS sequences allowed to identify a 14 bp consensus, similar to the S. cerevisiae ARS Consensus Sequence (ACS) but more constrained. The large tandem repeats identified in C. glabrata and called megasatellites, are not in close proximity to replication origins or termini. Using chromosome conformation capture, we show that early origins tend to cluster, as in the S. cerevisiae genome, whereas non-subtelomeric megasatellites do not cluster in the yeast nucleus. In conclusion, despite a shorter cell cycle, the C. glabrata replication program shares striking similarities to S. cerevisiae, despite their large evolutionary distance and the presence of highly repetitive large tandem repeats in C. glabrata.
Candida glabrata, like Saccharomyces cerevisiae, belongs to the Saccharomycetaceae yeasts that underwent whole-genome duplication. Here, using centrifugal elutriation and deep sequencing, we identified early and late replication fork origins, genomewide. Centromeres, HML and HMR loci and most histone genes are replicated early, whereas natural chromosomal breakpoints are located in late replicating regions. An ARS capture experiment allowed to identify 181 Autonomous Replication Sequences (ARS), and their relative fitness was determined during a growth competition experiment. Analysis of ARS sequences allowed to identify a 14 bp consensus, similar to the S. cerevisiae ARS Consensus Sequence (ACS) but more constrained. The large tandem repeats identified in C. glabrata and called megasatellites, are not in close proximity to replication origins or termini. Using chromosome conformation capture, we show that early origins tend to cluster, as in the S. cerevisiae genome, whereas non-subtelomeric megasatellites do not cluster in the yeast nucleus. In conclusion, despite a shorter cell cycle, the C. glabrata replication program shares striking similarities to S. cerevisiae, despite their large evolutionary distance and the presence of highly repetitive large tandem repeats in C. glabrata.