Project description:Leaves are colonised by a complex mix of microbes, termed the leaf microbiota. Even though the leaf microbiota is increasingly recognised as an integral part of plant life and health, our understanding of its interactions with the plant host is still limited. Here, mature, axenically grown Arabidopsis thaliana plants were spray-inoculated with diverse leaf-colonising bacteria. Whole transcriptome sequencing revealed that four days after inoculation, leaf transcriptional changes to colonisation by non-pathogenic and pathogenic bacteria differed in strength but not in the type of response.
2023-05-19 | GSE232251 | GEO
Project description:High molecular weight DNA extraction strategies for long-read sequencing of complex metagenomes
Project description:Human listeriosis cases are due to the ingestion of contaminated foods with the pathogenic bacteria Listeria monocytogenes. The reduction of water availability in food workshops by decreasing the air relative humidity (RH) is one strategy to improve the control of bacterial contamination. This study aims to develop and implement an MSI approach on L. monocytogenes biofilms and proof of concept using a dehumidified stress condition. MSI allowed examining the distribution of low molecular weight proteins within the biofilms subjected to a dehumidification environment, mimicking the one present in a food workshop (10°C, 75% RH). Furthermore, a LC-MS/MS approach was made to link the dots between MSI and protein identification. Five identified proteins were assigned to registered MSI m/z, including two cold-shock proteins and a ligase involved in cell wall biogenesis.
Project description:Based on the different chemistries of phenol extraction of RNA versus commercial kits, we hypothesized that certain species of mRNA may be preferentially extracted depending upon method, which could masquerade as differential expression in downstream RNA-seq experiments. We tested this using Saccharomyces cerevisiae samples that only differ in the RNA isolation method: a "standard" hot phenol extraction, versus two different commercial RNA isolation kits. While the kits had comparable relative mRNA abundances, samples isolated with hot phenol had higher relative abundance of mRNAs encoding membrane proteins. We hypothesize that hot phenol better solubilizes mRNAs associated with cellular membranes. We then compared the effects of each RNA isolation method on the ability to identify differentially expressed transcripts, using the yeast heat shock response a test case. The method of RNA isolation had little effect on the ability to identify differentially expressed transcripts. Thus, experiments within a single lab are unlikely to be affected by the choice of RNA isolation method as long as the same method is used throughout an experiment. For meta-analyses however, researchers should be cautious if trying to compare experiments where the RNA isolation methods differ.
Project description:To better understand the impact of infection on oocyte quality we employed global transcriptomics of oocytes collected from heifers after receiving intrauterine infusion of pathogenic Escherichia coli and Trueperella pyogenes. We hypothesized that oocyte transcriptome would be altered in response to intrauterine infection. A total of 452 differentially expressed genes were identified in oocytes collected from heifers 4 days after bacteria infusion compared to vehicle infusion, while 539 differentially expressed genes were identified in oocytes collected from heifers 60 days after bacteria infusion. Only 42 genes were differentially expressed in bacteria infused heifers at both day 4 and day 60. Interferon, HMGB1, ILK, IL-6 and TGF-beta signaling pathways were downregulated in oocytes collected at day 4 from bacteria infused heifers, while interferon, ILK and IL-6 signaling were upregulated in oocytes collected at day 60 from bacteria infused heifers. These data suggest that bacterial infusion alters the oocyte transcriptome differently at day 4 and day 60, suggesting different follicle stages are susceptible to damage. Characterizing the long-term impacts of uterine infection on oocyte transcriptome aids in our understanding of how infection causes infertility in dairy cattle.
Project description:au07-07_salmonella - infection with Salmonella or Pseudomonas or E. coli. Identification of genes involved in early Arabidopsis response to pathogenic and non-pathogenic bacteria. Arabidopsis thaliana Col-0 seedlings were infected for 2 hours with a) Salmonella typhimurium strain 14028s, b) Pseudomonas syringae DC3000 or c) Escherichia coli DH5A Keywords: treated vs untreated comparison 6 dye-swap - CATMA arrays
