Adenylyl cyclase mRNA localizes to the posterior of polarized DICTYOSTELIUM cells during chemotaxis

In Dictyostelium discoideum, vesicular transport of the adenylyl cyclase A (ACA) to the posterior of polarized cells is essential to relay exogenous 3′,5′-cyclic adenosine monophosphate (cAMP) signals during chemotaxis and for the collective migration of cells in head-to-tail arrangements called streams. Using fluorescence in situ hybridization (FISH), we discovered that the ACA mRNA is asymmetrically distributed at the posterior of polarized cells. Using both standard estimators and Monte Carlo simulation methods, we found that the ACA mRNA enrichment depends on the position of the cell within a stream, with the posterior localization of ACA mRNA being strongest for cells at the end of a stream. By monitoring the recovery of ACA-YFP after cycloheximide (CHX) treatment, we observed that ACA mRNA and newly synthesized ACA-YFP first emerge as fluorescent punctae that later accumulate to the posterior of cells. We also found that the ACA mRNA localization requires 3′ ACA cis-acting elements. Together, our findings suggest that the asymmetric distribution of ACA mRNA allows the local translation and accumulation of ACA protein at the posterior of cells. These data represent a novel functional role for localized translation in the relay of chemotactic signal during chemotaxis.https://doi.org/10.1186/s12860-017-0139-

Enhancing Liquid-Phase Olefin-Paraffin Separations Using Novel Silver-Based Ionic Liquids

This paper describes the extraction of C5–C8 linear α-olefins from olefin/paraffin mixtures of the same carbon number using silver­(I)/<i>N,N</i>-dimethylbenzamide bis­(trifluoromethylsulfonyl)­imide ([Ag­(DMBA)₂]­[Tf₂N]) or silver­(I)/propylamine bis­(trifluoromethylsulfonyl)­imide ([Ag­(PrNH₂)₂]­[Tf₂N]) as the extracting agent. The separation performance of the system increased with increasing chain length. [Ag­(DMBA)₂]­[Tf₂N] appeared to outperform [Ag­(PrNH₂)₂]­[Tf₂N] in terms of both selectivity and distribution coefficient. The [Ag­(DMBA)₂]­[Tf₂N] system was successfully modeled using the universal quasi-chemical activity coefficient (UNIQUAC) model. These results support the potential future development of amine/amide-based ligands for producing soluble silver complexes useful for the separation of olefins from paraffins