Project description:The mitogenome sequence of Sponge Halichondria okadai (Kadota, 1922) (Suberitida, Halichondriidae) was determined for the first time in this study. The circular genome is 20,722 bp in length, containing 14 protein coding genes (PCGs), two ribosomal RNAs (rRNAs), and 25 transfer RNAs (tRNAs). The nucleotide composition of mitogenome consists of 29.5% A, 14.2% C, 21.5% G, 34.7% T, showing a high content of A + T similar to the other Suberitid sponges. These results will be useful for inferring the phylogenetic relationships among the members of family Halichondriidae within the Suberitids.
Project description:In this study, we found out the complete mitochondrial genome of Halichondria (Halichondria) sp., a common demosponge in China. This is the first complete mitochondrial report on the genus Halichondria. The mitochondrial genome of Halichondria (Halichondria) sp. is 20 746?bp in length, with 14 protein-coding genes, two rRNA genes and 25 tRNA genes. When compared with the complete mitochondrial genome of Hymeniacidon sinapium, our phylogenetic result suggested that Halichondria (Halichondria) sp. converged well according to morphological result.
Project description:Bacteria transform nutrients and degrade organic matter, making them an essential part of healthy ecosystems. By assaying bacterial physiology within a complex system, the status of the whole ecosystem can be investigated. Proteins are the dynamic molecules that control essential bacterial physiological responses and those of every organism; characterizing an organism's proteome can therefore provide information on its interaction with the environment. Data dependen proteomic analysis (DDA) is a global approach to assay the entire proteome, but sample complexity and the stochastic nature of mass spectrometry can make it difficult to detect low abundance proteins. We explored the development of targeted proteomic (selected reaction monitoring, SRM) assays in complex ocean samples in order to detect specific bacterial proteins of interest and to assess new tools for mixed community metaproteomic exploration. A mixed community was created from a dilution series of isolated culture of bacteria (Ruegeria pomoeroyi) and phytoplankton (Thalassiosira pseudonana). Using SRM, we were able to detect bacterial peptides from the community that were undetectable with the standard DDA approach. We demonstrate benefits and drawbacks of different proteomic approaches that can be used to probe for and resolve nuances of bacterial physiological processes in complex environmental systems.
Project description:Bacteria transform nutrients and degrade organic matter, making them an essential part of healthy ecosystems. By assaying bacterial physiology within a complex system, the status of the whole ecosystem can be investigated. Proteins are the dynamic molecules that control essential bacterial physiological responses and those of every organism; characterizing an organism's proteome can therefore provide information on its interaction with the environment. Data dependen proteomic analysis (DDA) is a global approach to assay the entire proteome, but sample complexity and the stochastic nature of mass spectrometry can make it difficult to detect low abundance proteins. We explored the development of targeted proteomic (selected reaction monitoring, SRM) assays in complex ocean samples in order to detect specific bacterial proteins of interest and to assess new tools for mixed community metaproteomic exploration. A mixed community was created from a dilution series of isolated culture of bacteria (Ruegeria pomoeroyi) and phytoplankton (Thalassiosira pseudonana). Using SRM, we were able to detect bacterial peptides from the community that were undetectable with the standard DDA approach. We demonstrate benefits and drawbacks of different proteomic approaches that can be used to probe for and resolve nuances of bacterial physiological processes in complex environmental systems.
Project description:The lysosome, as the main degradative organelle of eukaryotic cells, is involved in numerous cellular processes. A defect in one of its proteins often results in lysosomal storage diseases (LSDs). For the study of lysosomal proteins, mass spectrometry (MS) has emerged as the method of choice. Lysosomal proteins are, however, low-abundant, restricting the analysis of lysosomal proteins in unbiased approaches to the investigation of lysosome-enriched fractions. The use of targeted MS provides an attractive alternative to analyze lysosomal proteins in a complex background. In this study, the two targeted MS approaches data-independent acquisition (DIA) and parallel reaction monitoring (PRM) were compared with regard to their ability to analyse lysosomal proteins. These experiments were conducted with samples of different complexity: low-complex lysosome-enriched fractions, medium-complex mouse embryonic fibroblasts (MEF), and high-complex liver whole tissue lysate. While both MS approaches were able to identify and quantify lysosomal proteins, PRM outperformed DIA, especially in high-complex samples.
Project description:Bacterial transcription networks typically consist of hundreds of transcription factors and thousands of promoters. However, current attempts to map bacterial promoters have failed to report the true complexity of bacterial transcription. The differential RNA-seq (dRNA-seq) approaches only identified a subset of promoters because they involved few growth conditions. Here, we present a simplified approach for global promoter identification in bacteria, based upon the analysis of RNA-seq data from multiple environmental conditions. RNA was extracted from Salmonella enterica serovar Typhimurium (S. Typhimurium) grown in 22 different environmental conditions, which were devised to reflect the pathogenic lifestyle of S. Typhimurium. Individual RNA samples were combined into two pools for sequencing. In just two runs of strand-specific RNA-seq and dRNA-seq of the pooled sample we identified 3701 promoters (Pool sample). In further experiments, we found that individual in vitro conditions stimulate the expression of about 60% of the S. Typhimurium genome, whereas the suite of 22 conditions induced expression of 87% of S. Typhimurium genes. We discovered environmental conditions that induce many genes within Salmonella pathogenicity islands and identified 78 new sRNAs. In S. Typhimurium there is now experimental evidence for 280 sRNAs, and we classified them in terms of location and Hfq-binding. Transcriptome analysis of S. Typhimurium 4/74 using RNA from 22 different conditions using RNA-seq. Also, RNA from each condition was pooled into one sample (RNA Pool). Differential RNA-seq (dRNA-seq) was performed for 5 of the samples from the 22 environmental conditions.
Project description:To determine whether and how warming affects the functional capacities of the active microbial communities, GeoChip 5.0 microarray was used. Briefly, four fractions of each 13C-straw sample were selected and regarded as representative for the active bacterial community if 16S rRNA genes of the corresponding 12C-straw samples at the same density fraction were close to zero.
Project description:Bacterial transcription networks typically consist of hundreds of transcription factors and thousands of promoters. However, current attempts to map bacterial promoters have failed to report the true complexity of bacterial transcription. The differential RNA-seq (dRNA-seq) approaches only identified a subset of promoters because they involved few growth conditions. Here, we present a simplified approach for global promoter identification in bacteria, based upon the analysis of RNA-seq data from multiple environmental conditions. RNA was extracted from Salmonella enterica serovar Typhimurium (S. Typhimurium) grown in 22 different environmental conditions, which were devised to reflect the pathogenic lifestyle of S. Typhimurium. Individual RNA samples were combined into two pools for sequencing. In just two runs of strand-specific RNA-seq and dRNA-seq of the pooled sample we identified 3701 promoters (Pool sample). In further experiments, we found that individual in vitro conditions stimulate the expression of about 60% of the S. Typhimurium genome, whereas the suite of 22 conditions induced expression of 87% of S. Typhimurium genes. We discovered environmental conditions that induce many genes within Salmonella pathogenicity islands and identified 78 new sRNAs. In S. Typhimurium there is now experimental evidence for 280 sRNAs, and we classified them in terms of location and Hfq-binding.