In this week's Science, a team led by the University of Washington's John Stamatoyannopoulos reports on a study comparing regions of mouse and human DNA that control gene expression, finding that about a third of them are conserved between the two species. Working in conjunction with the Mouse ENCODE Consortium, the researchers mapped the mouse regulatory DNA landscape in 45 mouse cell and tissue types using sites called DNAse I hypersensitive sites (DHSs), which typically mark gene regulatory regions. The findings were compared with DHS maps from corresponding human cells and tissues. Notably, some of the shared DHSs were farther from the genes they influenced than were DHSs that weren't shared, suggesting that the DHSs that have been conserved throughout mammalian evolutionary history may be functionally different from DHSs closer to the gene they control. GenomeWeb has more on the Mouse ENCODE papers here.
Also in Science, a Harvard Medical School group reports data showing that epigenetic information can be transmitted through histone modifications independently of DNA sequence, DNA methylation, or RNAi. In fission yeast, they showed that ectopically induced domains for histone H3 lysine 9 methylation — a conserved marker of heterochromatin — are inherited through mitotic and meiotic cell divisions even after the removal of the sequence-specific initiator.