miRNA-7-5p inhibits melanoma cell migration and invasion

Aberrant expression of microRNAs (miRNAs), a class of small non-coding regulatory RNAs, has been implicated in the development and progression of melanoma. However, the precise mechanistic role of many of these miRNAs remains unclear. We have investigated the functional role of miR-7-5p in melanoma, and demonstrate that miR-7-5p expression is reduced in metastatic melanoma-derived cell lines compared with primary melanoma cells, and that when ectopically expressed miR-7-5p significantly inhibits melanoma cell migration and invasion. Additionally, we report that insulin receptor substrate-2 (IRS-2) is a target of miR-7-5p in melanoma cells, and using RNA interference (RNAi) we provide evidence that IRS-2 activates protein kinase B (Akt), and promotes melanoma cell migration. Thus, miR-7-5p may represent a novel tumor suppressor miRNA in melanoma, acting at least in part via its inhibition of IRS-2 expression and oncogenic Akt signaling.     

Genome sequence of the squalene-degrading bacterium Corynebacterium terpenotabidum type strain Y-11T (= DSM 44721T)

Corynebacterium terpenotabidum Takeuchi et. al 1999 is a member of the genus Corynebacterium, which contains Gram-positive and non-spore forming bacteria with a high G+C content. C. terpenotabidum was isolated from soil based on its ability to degrade squalene and belongs to the aerobic and non-hemolytic Corynebacteria. It displays tolerance to salts (up to 8%) and is related to Corynebacterium variabile involved in cheese ripening. As this is a type strain of Corynebacterium, this project describing the 2.75 Mbp long chromosome with its 2,369 protein-coding and 72 RNA genes will aid the Genomic Encyclopedia of Bacteria and Archaea project.     

Diagnostic single nucleotide polymorphisms for identifying westslope cutthroat trout (Oncorhynchus clarki lewisi), Yellowstone cutthroat trout (Oncorhynchus clarkii bouvieri) and rainbow trout (Oncorhynchus mykiss)

We describe 12 diagnostic single nucleotide polymorphism (SNP) assays for use in species identification among rainbow and cutthroat trout: five of these loci have alleles unique to rainbow trout (Oncorhynchus mykiss), three unique to westslope cutthroat trout (O. clarkii lewisi) and four unique to Yellowstone cutthroat trout (O. clarkii bouvieri). These diagnostic assays were identified using a total of 489 individuals from 26 populations and five fish hatchery strains.     

Programmable chronopotentiometry as a tool for the study of electroporation and resealing of pores in bilayer lipid membranes

This paper presents the application of chronopotentiometry in the study of membrane electroporation. Chronopotentiometry with a programmable current intensity was used. The experiments were performed on planar bilayer phosphatidylcholine and cholesterol membranes formed by the Mueller-Rudin method. It was demonstrated that a constant-intensity current flow through the bilayer membranes generated voltage fluctuations during electroporation. These fluctuations (following an increase and decrease in membrane conductance) were interpreted as a result of the opening and closing of pores in membrane structures. The decrease in membrane potential to zero did not cause the pore to close immediately. The pore was maintained for about 200 s. The closing of the pore and recovery of the continuous structure of the membrane proceeded not only when the membrane potential equalled zero, but also at membrane potentials up to several tens of millivolts. The fluctuations of the pore were possible at values of membrane potential in the order of at least 100 mV. The size of the pore changed slightly and it closed after some time below this potential value.