In this week's Nature, researchers from Cold Spring Harbor Laboratory and the University of Cambridge report on the discovery of the mechanism that underlies a key defect in certain oil palm trees. High-yield varieties of the tree are propagated to grow clones that are supplied to plantations. However, these tress can develop an epigenetic defect, called mantling, that results in abnormal fruit and a reduce oil yield. By performing an epigenome-wide association study on four groups of oil palms, the investigators identified an inactive DNA sequence called Karma, located within the gene EgDEF1, that is heavily methylated in normal palms, but not in mantled ones. The loss of DNA methylation, the study shows, affects the processing of the EgDEF1 gene transcript, which is required for normal flower formation. GenomeWeb has more on this study, here.
And in Nature Genetics, an international team of scientists presents a genome-wide association meta-analysis of coronary artery disease based on data from the 1000 Genomes Project. The group confirmed most known CAD-associated loci, but also identified 10 new loci that contain candidate causal genes that implicate new biological processes in blood vessel walls.
Meanwhile, in Nature Methods, Harvard University and Massachusetts Institute of Technology investigators detail a technique for CRISPR-based genome editing, activation, and repression. By altering the length of the protein that guides Cas9 to a target location in the genome where it induces double-strand breaks in DNA, the team could simultaneously perform genome editing and transcriptional regulation with a single Cas9 protein. They used this approach to create mammalian synthetic circuits with combined transcriptional regulation and kill functions.