Project description:The aim of this analysis was to better understand the complex symbiotic stage of Tuber melanosporum by combining the use of laser capture microdissection and microarray gene expression analysis. We isolated the fungal/soil (i.e. the mantle) and the fungal/plant (i.e. the Hartig net) interfaces from transverse sections of T. melanosporum/Corylus avellana ectomycorrhizas and identified the transcriptional landscape associated with each compartment. We compared these data to the transcriptome of ectomycorrhizal root tips, free-living mycelium and fruiting bodies of Tuber melanosporum (Series GSE17529). The T. melanosporum custom-exon expression array (4 x 72K) manufactured by Roche NimbleGen Systems Limited (Madison, WI) contained five independent, nonidentical, 60-mer probes per gene model coding sequence. Included in the oligoarray were 12,232 annotated gene models, 3,913 random 60-mer control probes and labelling controls. Sequences used for the oligonucleotide design were from an early draft of the gene catalog containing several TE families. For 1,876 gene models, technical duplicates were included on the array. We performed 6 hybridizations (NimbleGen) with samples derived from microdissected mantles (3 biological replicates) and Hartig nets ((3 biological replicates each) from T. melanosporum/Corylus avellana ectomycorrhizal root tips . All samples were labeled with Cy3.
Project description:The aim of this analysis was to better understand the complex symbiotic stage of Tuber melanosporum by combining the use of laser capture microdissection and microarray gene expression analysis. We isolated the fungal/soil (i.e. the mantle) and the fungal/plant (i.e. the Hartig net) interfaces from transverse sections of T. melanosporum/Corylus avellana ectomycorrhizas and identified the transcriptional landscape associated with each compartment. We compared these data to the transcriptome of ectomycorrhizal root tips, free-living mycelium and fruiting bodies of Tuber melanosporum (Series GSE17529).
Project description:Analyses of new genomic, transcriptomic or proteomic data commonly result in trashing many unidentified data escaping the ‘canonical’ DNA-RNA-protein scheme. Testing systematic exchanges of nucleotides over long stretches produces inversed RNA pieces (here named “swinger” RNA) differing from their template DNA. These may explain some trashed data. Here analyses of genomic, transcriptomic and proteomic data of the pathogenic Tropheryma whipplei according to canonical genomic, transcriptomic and translational 'rules' resulted in trashing 58.9% of DNA, 37.7% RNA and about 85% of mass spectra (corresponding to peptides). In the trash, we found numerous DNA/RNA fragments compatible with “swinger” polymerization. Genomic sequences covered by «swinger» DNA and RNA are 3X more frequent than expected by chance and explained 12.4 and 20.8% of the rejected DNA and RNA sequences, respectively. As for peptides, several match with “swinger” RNAs, including some chimera, translated from both regular, and «swinger» transcripts, notably for ribosomal RNAs. Congruence of DNA, RNA and peptides resulting from the same swinging process suggest that systematic nucleotide exchanges increase coding potential, and may add to evolutionary diversification of bacterial populations.