Project description:Pandoravirus aubagnensis was isolated from freshwater collected from “Manon des Sources” in Marseille city,France. By co-culture on Acanthamoeba castellanii. Pandoravirus belohorizontensis was isolated from soil samples collected from Belo Horizonte city in Brazil, by co-culture on Acanthamoeba castellanii.
Project description:Proteome analysis of a novel type of virus. The virus was grown in A. castellanii amobea before being purified. Viral particules were enriched after centrifugation and proteins solubilised by SDS before being stacked in the top of a SDS-PGE gel. After in-gel digestion, resulting peptides were injected for a 120min nanoLC-MS/MS analysis using an Ultimate U3000 system and a LTQ-Orbitrap Velos pro hybrid mass spectrometer (Top 20).Data processing and bioinformatics: Data were processed automatically using Mascot Daemon software (version 2.3.2, Matrix Science). Concomitant searches against Pandoravirus and A. castellanii protein sequence databanks as well as classical contaminants database and the corresponding reversed databases were performed using Mascot (version 2.4). ESI-TRAP was chosen as the instrument, trypsin/P as the enzyme and 2 missed cleavage allowed. Precursor and fragment mass error tolerances were set respectively at 10 ppm and 0.6 Da. Peptide modifications allowed during the search were: carbamidomethyl (C, fixes) acetyl (N-ter, variable), oxidation (M, variable) and deamidation (NQ, variable). The IRMa software (Dupierris et al., Bioinformatics, 2009, 25:1980-1, version 1.30.4) was used to filter the results: selection of rank 1 peptides, peptide identification FDR < 1% (as calculated by employing the reverse database strategy), and minimum of 1 specific peptide per identified protein group.
Project description:Epigenetic variation has the potential to control environmentally dependent development and contribute to phenotypic responses to local environments. Environmental epigenetic studies of sexual organisms confirm the responsiveness of epigenetic variation, which should be even more important when genetic variation is lacking. A previous study of an asexual snail, Potamopyrgus antipodarum, demonstrated that different populations derived from a single clonal lineage differed in both shell phenotype and methylation signature when comparing lake versus river populations. Here, we examine methylation variation among lakes that differ in environmental disturbance and pollution histories. The differential DNA methylation regions (DMRs) identified among the different lake comparisons suggested a higher number of DMRs and variation between rural Lake 1 and one urban Lake 2 and between the two urban Lakes 2 and 3, but limited variation between the rural Lake 1 and urban Lake 3. DMR genomic characteristics and gene associations were investigated. Observations suggest there is no effect of geographic distance or any consistent pattern of DMRs between urban and rural lakes. Environmental factors may influence epigenetic response.