A new study by Paolo Giacobini, Vincent Prevot and colleagues shows that Semaphorin 3A produced by endothelial cells in the adult rodent brain promotes the outgrowth of axons and thereby regulates the secretion of gonadotropin-releasing hormone in response to the ovarian cycle.
Networks of local interactions regulate biological systems. In this Essay Deborah Gordon finds that ecological constraints set by resource distribution operating costs and the threat of rupture produce similar collective behavior in ants, cells and gene transcription.
Image Credit: journal.pbio.0020324.g001
Structural and biochemical analysis of the bacterial exonuclease RNase T by Yu-Yuan Hsiao, Hanna Yuan and colleagues reveals that it plays a role in DNA repair pathways, where it binds bulge, bubble and Y-structured DNA and trims the 3' ends of DNA strands. Read more in this Synopsis.
Using chemical genetics and a global comparative analysis of protein and lipid phosphorylation, Mathieu Brochet, Oliver Billker and colleagues have identified protein kinase G as the upstream regulator that induces the calcium signals required for Plasmodium to progress through its complex life cycle.