Investigators at Duke University report in a PNAS paper published online in advance this week on their use of human artificial chromosome assembly assays, with which they show that "both D17Z1 and D17Z1-B can support de novo centromere assembly independently." This study, the authors say, illustrates the "presence of centromeric epialleles on an endogenous human chromosome" and points to the "genomic complexities underlying the mechanisms that determine centromere identity in humans."
Elsewhere in this week's Early Edition, scientists at Lawrence Berkeley National Laboratory and Stanford University present a method for the "delivery of small molecules and proteins across the cell wall of algae using molecular transporters" known as guanidinium-rich molecular transporters, or GR-MoTrs. "Significantly, this method is shown to work in wild-type algae that have an intact cell wall," the authors write, adding that it though it was "developed using Chlamydomonas reinhardtii, this method is also successful with less studied algae including Neochloris oleoabundans and Scenedesmus dimorphus, thus providing a new and versatile tool for algal research."