Trees.Genome RearrangementsResults and Discussion Bacterial evolution at genomic level requires
Trees.Genome RearrangementsResults and Discussion Bacterial evolution at genomic level involves accumulation of mutations, genome rearrangements and horizontal gene transfer.The contribution of all these distinctive and independent evolutionary events towards speciation and adaptation of thermophilic bacteria of genus Thermus had been analysed.Thermus bacteria is of industrial interest on account of their ability to withstand intense abiotic stresses which includes the higher temperature and highenergy irradiation ; as well as because of their function in PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/21323637 decontamination in the environmental pollutions and ability to synthesize thermostable enzymes for industrial application .Identification of orthologous genesTo determine orthologous genes for investigating probable gene exchanges among numerous bacteria species, a BLASTp search was accomplished in a pairwise manner for all coding sequences of sampled genomes Thermus thermophilus HB and HB, T.scotoductus SA, T.aquaticus YMC, T.igniterrae ATCC , T.oshimai JL, Thermus sp.RL, Thermus sp.CCB US UF, Meiothermus silvanus DSM and Meiothermus ruber DSM .In total , groups of orthologous protein shared by studied genomes were discovered.All these sequences had been aligned by MUSCLE and individual gene trees for every alignment exactly where created by the NeighbourJoining (NJ) algorithm applying PHYLIP executable files along with the whole set of trees was analysed by SplitsTree to rebuild a reticulation network (Figure A).An additional strategy of phylogenetic reconstruction was concatenating all alignmentsBacteria from the genus Thermus are characterized with remarkably greater levels of genome rearrangements .DNA fragments of S-[(1E)-1,2-dichloroethenyl]–L-cysteine custom synthesis diverse length had been continuously mobile and moving to new places around the chromosomes of those organisms.According to the evaluation of your phylogenetic tree in Figure , Meiothermus silvanus DSM was identified as a suitable reference genome to investigate rearrangements in Thermus organisms, since it was at an roughly equal evolutionary distance in the target genomes.Alignment of sequences of whole chromosomes was performed by the system Mauve only for organisms of which complete genome sequences had been finished (Figure A).The progressive alignment algorithm implemented in Mauve permits also developing a phylogenetic tree determined by analysis of genome rearrangements (Figure B).An incredible quantity of rearrangements have been noted and it was an exciting observation that the extreme thermophiles T.thermophilus, T.oshimai and Thermus sp.CCB US UF had been clustered collectively and aside from the thermotolerant T.scotoductus (Figure B) in spite of their taxonomic diversity (Figure B).A lot more rearrangements were observed in intense thermophiles as when compared with T.scotoductus SA (note bigger synteny blocks within the chromosome of T.scotoductus in Figure A), having said that this difference was not statistically trusted.Even though there isn’t any biological evidence to back up rearrangements as an adaptation mechanism in thermophilic organisms, it may be attainable that some unknown adaptation mechanism to thermal environments triggers them.In the further study we focused on comparison of M.silvanus DSM , T.scotoductus SA, T.thermophilus HB and HB as representatives of thermotolerant and really thermophilic organisms.A comparison of typical lengths of operons (average number of genes) predicted by Pathway Tools computer software showed that M.silvanus DSM operons had been longerKumwenda et al.BMC Genomics , www.biomedcentral.comPage ofFigure Phylogenetic relationships among studied organisms.A).