Barrier Crossing in Escherichia coli Chemotaxis.

We study cell navigation in spatiotemporally complex environments by developing a microfluidic racetrack device that creates a traveling wave with multiple peaks and a tunable wave speed. We find that while the population-averaged chemotaxis drift speed increases with wave speed for low wave speed, it decreases sharply for high wave speed. This reversed dependence of population-averaged chemotaxis drift speed on wave speed is caused by a "barrier-crossing" phenomenon, where a cell hops backwards from one peak attractant location to the peak behind by crossing an unfavorable (barrier) region with low attractant concentrations.

Arginine Is a Critical Substrate for the Pathogenesis of in Burn Wound Infections.

Environmental conditions affect bacterial behavior and can greatly influence the course of an infection. However, the environmental cues that elicit bacterial responses in specific infection sites are relatively unknown. is ubiquitous in nature and typically innocuous.

Singly Flagellated Pseudomonas aeruginosa Chemotaxes Efficiently by Unbiased Motor Regulation.

Unlabelled: Pseudomonas aeruginosais an opportunistic human pathogen that has long been known to chemotax. More recently, it has been established that chemotaxis is an important factor in the ability ofP. aeruginosato make biofilms.

MDM4 regulation by the let-7 miRNA family in the DNA damage response of glioma cells.

Despite extensive investigation into the role of let-7 miRNAs in pathological tumor processes, their involvement in the DNA damage response remains unclear. Here we show that most let-7 family members down-regulate MDM4 expression via binding to MDM4 mRNA at a conserved DNA sequence. Expression of exogenous let-7 miRNA mimics decreased MDM4 protein but not mRNA levels.