Project description:Using whole genome microarrays based on the annotated genomes of Postia placenta, we monitored the changes in its transcriptomes relevant to cell wall degradation during growth on three chemically distinct Populus trichocarpa (poplar) wood substrates. The research goal is to identtify genes essential for cellulose depolymerization. From a data set of 12438 unique gene models, each NimbleGen (Madison, WI) array targeted 9959 genes and featured 10 unique 60mers per gene, all in triplicate. RNA and protein were obtained from P. placenta strain MAD-698-R (USDA Forest Mycology Center, Forest Products Laboratory, Madison WI) grown in malt extract agar for 10 days prior to inoculation with wood wafers. Three poplar wood substrates with distinct cell wall chemical properties were selected from several hundred 4-year old poplar (Populus trichocarpa) trees grown in a common garden field trial at the University of British Columbia (Canada). We selected three poplar genotypes based on cell wall chemical traits. Substrate A corresponds to a genotype with a higher than average lignin content and lower that average glucose content; Substrate B, a lower than average lignin content and higher that average glucose content; Substrate C lignin and glucose contents are near the population average. Poplar wood stems were cut into 0.5 mm wafers on a microtome, sterilized for 20 min at 121°C, dried at 50°C overnight, and cooled to room temperature. The specimens were then inoculated in Petri dishes with actively growing mycelia. Approximately 5 g of wood wafers were placed in each Petri dish (exact weights were recorded), sealed and incubated at 22°C and 70 ± 5% relative humidity for 10, 20 or 30 days. For RNA, the degraded wafers were removed from the Petri dishes, immediately snap-frozen in liquid nitrogen and stored at -80°C for later use. Total RNA was converted to Cy3 labelled cDNA, hybridized to microarrays and scanned as previously described by Vanden Wymelenberg et al 2010 (Appl Enviro Microbiol 76:3599-3610).The 24 arrays per fungal species were scanned and data extracted using NimbleScan v.2.4. The raw data was loaded into GeneSpring, where the intensities were converted to log2 and quantile normalized, and all probes per gene averaged. This data was then exported and further analyzed in R. For substrates “A” and “B”, three replicates were used for each wood substrate/fungus and incubation period combination. For substrate “C” only 2 biological replicates were employed.
Project description:Using whole genome microarrays based on the annotated genomes of Phanerochaete chrysosporium, we monitored the changes in its transcriptomes relevant to cell wall degradation during growth on three chemically distinct Populus trichocarpa (poplar) wood substrates. Results of this study are sumbitted for review in Biotechnology for Biofuels From a data set of 10004 unique gene models, each NimbleGen (Madison, WI) array targeted 9959 genes and featured 12 unique 60mers per gene, all in triplicate. RNA and protein were obtained from P. chrysosporium strain RP-78 (USDA Forest Mycology Center, Forest Products Laboratory, Madison WI) grown in malt extract agar for 10 days prior to inoculation with wood wafers. Three poplar wood substrates with distinct cell wall chemical properties were selected from several hundred 4-year old Populus trichocarpa trees grown in a common garden field trial at the University of British Columbia (Canada). We selected three poplar genotypes based on cell wall chemical traits. Substrate A corresponds to a genotype with a higher than average lignin content and lower that average glucose content; Substrate B, a lower than average lignin content and higher that average glucose content; Substrate C lignin and glucose contents are near the population average. Poplar wood stems were cut into 0.5 mm wafers on a microtome, sterilized for 20 min at 121°C, dried at 50°C overnight, and cooled to room temperature. The specimens were then inoculated in Petri dishes with actively growing mycelia. Approximately 5 g of wood wafers were placed in each Petri dish (exact weights were recorded), sealed and incubated at 22°C and 70 ± 5% relative humidity for 10, 20 or 30 days. For RNA, the degraded wafers were removed from the Petri dishes, immediately snap-frozen in liquid nitrogen and stored at -80°C for later use. Total RNA was converted to Cy3 labelled cDNA, hybridized to microarrays and scanned as previously described by Vanden Wymelenberg et al 2010 (Appl Enviro Microbiol 76:3599-3610).The 24 arrays per fungal species were scanned and data extracted using NimbleScan v.2.4. The raw data was loaded into GeneSpring, where the intensities were converted to log2 and quantile normalized, and all probes per gene averaged. This data was then exported and further analyzed in R. For substrates “A” and “B”, three replicates were used for each wood substrate/fungus and incubation period combination. For substrate “C” only 2 biological replicates were employed.
Project description:We report a high resolution catalouge of NMD substrates using RNA-Seq. We discovered several hundred new substrates for NMD. Using published ribosome footprint profiling data, we measured ribosome densities of normal-looking NMD substrates and non-NMD substrates. NMD substrates exhibited a striking difference in normalized ribosome occupancy in wild-type and UPF1 cells. We also found that normal looking NMD substrates have higher ratio of out of frame reads, lower codon optimalites and a higher propensity to have long stretches of non-optimal codons.
Project description:<p><strong>AIM:</strong> Low-molecular-weight organic substances (LMWOSs) are at the nexus between micro-organisms, plant roots, detritus and the soil mineral matrix. The nominal oxidation state of carbon (NOSC) has been suggested as a potential parameter for modelling microbial uptake rates of LMWOSs and the efficiency of carbon incorporation into new biomass.</p><p><strong>METHODS AND RESULTS: </strong>In this study, we assessed the role of compound class and oxidation state on uptake kinetics and substrate-specific carbon use efficiency (SUE) during the growth of three model soil micro-organisms, a fungal isolate (Penicillium spinulosum) and two bacterial isolates (Paraburkholderia solitsugae, and Ralstonia pickettii). Isolates were chosen that spanned a growth rate gradient (0.046-0.316 h-1) in media containing 34 common LMWOSs at realistically low initial concentrations (25 μM each). Clustered, co-utilization of LMWOSs occurred for all three organisms. Potential trends (p < 0.05) for early utilization of more oxidized substrates were present for the two bacterial isolates (P. solitsugae and R. pickettii), but high variability (R2 < 0.15) and a small effect of NOSC indicate these relationships are not useful for prediction. The SUEs of selected substrates ranged from 0.16 to 0.99 and there was no observed relationship between NOSC and SUE.</p><p><strong>CONCLUSION:</strong> Our results do not provide compelling population-level support for NOSC as a predictive tool for either uptake kinetics or the efficiency of use of LMWOS in soil solution.</p><p><strong>SIGNIFICANCE AND IMPACT OF THE STUDY:</strong> Metabolic strategies of organisms are likely more important than chemical identity in determining LMWOS cycling in soils. Previous community-level observations may be biased towards fast-responding bacterial community members.</p>
Project description:The intra-erythrocytic developmental cycle (IDC) of malaria parasites is synchronized with the time-of-day hosts feed, but the mechanism underpinning this coordination is unknown. Combining in vivo and in vitro approaches using rodent and human malaria parasites, we reveal that: (i) 57% of P. chabaudi genes exhibit 24 h “circadian” periodicity in expression; (ii) 58% of these genes lose rhythmicity when the IDC is out-of-synchrony with host rhythms; (iii) 6% of P. falciparum genes show circadian expression under free-running conditions; (iv) Serpentine receptor 10 (SR10) is circadian and disrupting it in rodent models shortens the IDC by 2-3 hours; (v) diverse processes, including DNA replication, the ubiquitin and proteasome pathways, are affected by disruption of SR10 and loss of coordination with host rhythms. Our results reveal that malaria parasites are at least in part responsible for scheduling their IDC, explaining the fitness benefits of coordination with host rhythms.
Project description:The aim of the study was to determine biological relevance of differentially expressed genes in Lactobacillus plantarum C2 during fermentation of plant substrates. Whole-transcriptome analysis based on customized microarray profiles has been used to determine altered transcription patterns in L. plantarum C2. L. plantarum C2 was grown (24 h at 30°C) and stored ( 21 days at 4°C) in carrot or pineapple juices to mimic the chemical composition of the respective raw matrices. De Man, Rogosa and Sharpe broth was used as the control medium for optimal growth. Samples were analyzed at the late exponential phase of growth and after storage