Functional genes and thermophilic microorganisms responsible for arsenite oxidation from the shallow sediment of an untraversed hot spring outlet.

Hot Springs have unique geochemical features. Microorganisms-mediated arsenite oxidation is one of the major biogeochemical processes occurred in some hot springs. This study aimed to understand the diversities of genes and microorganisms involved in arsenite oxidation from the outlet of an untraversed hot spring located at an altitude of 4226 m. Microcosm assay indicated that the microbial community from the hot spring was able to efficiently oxidize As(III) using glucose, lactic acid, yeast extract or sodium bicarbonate as the sole carbon source. The microbial community contained 7 phyla of microorganisms, of which Proteobacteria and Firmicutes are largely dominant; this composition is unique and differs significantly from those of other described hot springs. Twenty one novel arsenite oxidase genes were identified from the samples, which are affiliated with the arsenite oxidase families of α-Proteobacteria, ß-Proteobacteria or Archaea; this highlights the high diversity of the arsenite-oxidizing microorganisms from the hot spring. A cultivable arsenite-oxidizer Chelatococcu sp. GHS311 was also isolated from the sample using enrichment technique. It can completely convert 75.0 mg/L As(III) into As(V) in 18 days at 45 °C. The arsenite oxidase of GHS311 shares the maximal sequence identity (84.7%) to that of Hydrogenophaga sp. CL3, a non-thermotolerant bacterium. At the temperature lower than 30 °C or higher than 65 °C, the growth of this strain was completely inhibited. These data help us to better understand the diversity and functional features of the thermophilic arsenite-oxidizing microorganisms from hot springs.

Meta-analysis of differentially expressed genes in autism based on gene expression data.

The purpose of this study was to identify differentially expressed (DE) genes and biological processes associated with changes in gene expression in autism. We performed a meta-analysis using new publicly available Gene Expression Omnibus (GEO) datasets of autism. We performed Gene Ontology (GO) enrichment analyses and pathway analysis using the Kyoto Encyclopedia of Genes and Genomes (KEGG). Ten GEO datasets, including 364 cases and 248 controls, were available for the meta-analysis. We identified 3105 genes that were consistently DE in autism (1425 upregulated and 1680 downregulated genes). We also found that 7 genes were associated with phospholipase A2 (PLA2), including LYPLA2P1, PLA2G4D, PNPLA2, LYPLA2, PLA2G6, PLA2G7, and PLA2G5. We found GO terms for molecular functions significantly enriched in structural constituent of ribosome (GO: 0003735, P = 1.87-E06) and transcription regulator activity (GO: 0030528, P = 8.86E-04), while for biological processes, the enriched GO terms were involved in translational elongation (GO: 0006414, P = 1.74E-12) and the response to cytokine stimuli (GO: 0034097, P = 2.76E-05). The most significant pathway in our KEGG analysis was the ribosome pathway (P = 7.90E-12). Our meta-analysis identified genes that were consistently DE and biological pathways associated with gene expression changes in autism.