Multiple Copies of Ribosomal RNA Genes Aid Yeast Genome Integrity
Japanese researchers identified mechanisms through which ribosomal RNA gene sequences help protect the genome following DNA damage by comparing four Saccharomyces cerevisiae strains with 20, 40, 80, or 110 copies of genes coding for rRNA. They found that strains with fewer copies of rDNA genes were more sensitive to DNA damage by chemicals or ultraviolet light, apparently due to a role for these rDNA copies in recombination repair and sister chromatid cohesion.
Team Maps Methylome During Cellular Differentiation
Laurent, Wong, et al, Genome Research
Using bisulfite sequencing with the Illumina Genome Analyzer, researchers from Singapore and the US mapped and compared DNA methylation patterns in human cells during three progressive stages of differentiation: embryonic stem cells, skin-like cells derived from embryonic stem cells, and primary neonatal skin cells. In the process, the team identified shared and cell type-specific methylation patterns, providing insights into how gene regulation shifts during development.
