An article in Cell by recent Molecular and Cell Biology Ph.D. graduate Susan Tran and coworkers demonstrates the power of single particle microscopy in combination with Drosophila genetics in studying molecular motors. Studying lipid droplet movement in embryos, they show that multiple motors are attached to droplets in vivo. Surprisingly, having multiple motors per droplet in vivo doesn’t result in higher velocities or distances traveled.
Microscopy (2): studying molecular motors
Cell cycle checkpoint from the stringent response
The stringent response in E.coli is a response to nutrient (typically amino acid) starvation and is characterized by the accumulation of the small molecular regulator ppGpp, and a global response in transcriptional regulation. In a new paper in PLoS Genetics, Daniel Ferullo and Susan Lovett examine chromosome segregation during the stringent respons and discuss what appears to be a novel G1-like cell cycle checkpoint in bacteria that occurs as the result.