Project description:The Ixodidea tick Dermacentor marginatus is a vector of many pathogens wide spread in Eurasia. Study of gene targets of the tick species provides insight to find novel tick protective antigen for drug development and vaccine targets. To obtain a broader picture of gene sequences and changes in expression level, we aimed to characterize the whole body transcriptome in D. marginatus adult female after engorgement and long-term starvation using RNA-seq. We have assembled and analyzed transcriptome of D. marginatus females 5 days after ecdysis, 24 h after a blood meal, and 6 months under controlled experimental conditions. Sequencing produced 30251 unigenes, of which 32% were annotated using Trinity. Gene expression was compared among groups differed by status as newly molted, starved and engorged female adult ticks. Nearly 1/3 of the unigenes in each group were differentially expressed compared to the other two group, and we found that the most numerous were proteins involved in catalytic and binding activities and apoptosis. Selected up-regulated differentially expressed genes in each group associated to protein, lipids, carbohydrate and chitin metabolism. Blood feeding and long-term starvation also caused genes differentially expressed in the defense response and antioxidant response. Finding the sequence information and expression pattern would be helpful in understanding molecular physiology of D. marginatus, and provides information for anti-tick vaccine and drug development.
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.
