Project description:Transcriptomic profiling of the diatom Thalassiosira pseudonana at normal and elevated CO2 levels and at normal and elevated light levels. Common reference total RNA (Agilent Quick-Amp Cy3-labeled) was used in all arrays as an internal standard.
Project description:DNA methylation has been associated with transcriptional repression of transposable elements. Here we describe the first DNA methylation deficient cell line of a diatom by generating DNMT5:KOs in Phaeodactylum tricornutum. These data show the extend of the loss of DNA methylation in DNMT5:KOs compared to the reference strain. All DNA methylation is lost in DNMT5:KOs.
Project description:Phytoplankton and bacteria form the base of marine ecosystems and their interactions drive global biogeochemical cycles. The effect of bacteria and bacteria-produced compounds on diatoms range from synergistic to pathogenic and can affect the physiology and transcriptional patterns of the interacting diatom. Here, we investigate physiological and transcriptional changes in the marine diatom Thalassiosira pseudonana induced by extracellular metabolites of a known antagonistic bacterium Croceibacter atlanticus. Mono-cultures of C. atlanticus released compounds that inhibited diatom cell division and elicited a distinctive phenotype of enlarged cells with multiple plastids and nuclei, similar to what was observed when the diatom was co-cultured with the live bacteria. The extracellular C. atlanticus metabolites induced transcriptional changes in diatom pathways that include recognition and signaling pathways, cell cycle regulation, carbohydrate and amino acid production, as well as cell wall stability. Phenotypic analysis showed a disruption in the diatom cell cycle progression and an increase in both intra- and extracellular carbohydrates in diatom cultures after bacterial exudate treatment. The transcriptional changes and corresponding phenotypes suggest that extracellular bacterial metabolites, produced independently of direct bacterial-diatom interaction, may modulate diatom metabolism in ways that support bacterial growth.
Project description:We isolate the cultivable microbiome of a diatom and show that different bacteria have commensal, antagonistic, or synergistic effects on the diatom. One synergistic bacterium enhances growth of the diatom by production of auxin, a phytohormone. The diatom and its synergistic bacterium appear to use auxin and tryptophan as signaling molecules that drive nutrient exchange. Detection of auxin molecules and biosynthesis gene transcripts in the Pacific Ocean suggests that these interactions are widespread in marine ecosystems.
Project description:Pseudo-nitzschia multiseries (Ps-n) is a toxigenic marine diatom that produces the neurotoxin, domoic acid. We screened for candidate genes that may be involved in domoic acid production by determining changes in transcript profiles in Ps-n cultures that were in late exponential (low-domoic-acid-producing) vs. stationary (high-domoic-acid-producing) growth states. We also identified a number of candidate reference genes for future RT-qPCR studies, based on their stability in this study.
Project description:This study used virological, histological, immunological and global gene expression to compare the virlence of two newly emerged 2009 H1N1 isolates (A/Mexico/InDRE4487/2009 and A/Mexico/4108/2009) and current seasonal H1N1 influenza strain (A/Kawasaki/UTK-4/2009) in experimentally infected cynomolgus macaques. We showed that infection of macaques with two genetically similar but clinically distinct SOIV isolates from the early stage of the pandemic (A/Mexico/4108/2009 and A/Mexico/InDRE4487/2009) resulted in upper and lower respiratory tract infections and clinical disease ranging from mild to severe pneumonia. Disease associated with these SOIV isolates was clearly advanced over the mild infection caused by A/Kawasaki/UTK-4/2009, a current seasonal strain.
Project description:To identify the molecular components involved in diatom cell division, global transcript level changes were monitored over the silicon-synchronized cell cycle the model diatom Thalassiosira pseudonana.
Project description:We performed small RNA sequencing on recently colonized female Aedes aegypti from Mexico and Brazil. We compare small RNA profiles in midguts and abdomens (without ovaries) either non-bloodfed or 48 hours post non-infectious bloodmeal.
