Study On RRNA Genes Mutation Of Recombinant Desert Oligotrophic Bacteria By Ion Beam Implantation Based On Denovo Sequencing

Low energy ion implant organisms technique is a kind of physical mutation breeding technique which has developed in recent years.In order to form new material,active N+ ion is applied to inject to biological sample and mix with target molecule,this new material can cause biological mutation and biological effect.In order to further understand the mutation of Desert Oligotrophic Bacteria(DOB)rRNA induced by low energy N+ implantation,the rRNA gene sequences of three recombinant DOB strains(DOB073,DOB113,DOB981)and original strain DOB150 were analyzed by bioinformatics method which based on the De novo sequencing of DOB genome.We studied the basic rule and specific sites of gene mutation,statisticed copy number of mutants and GC content,and calculated the evolutionary distance and molecular clock of these gene sequences,then built the phylogenetic tree by obtaining the 5srRNA?16srRNA?23srRNA gene sequences of these DOB strains which come from the De novo sequencing of DOB genome data.We also analyzed the degree of evolution of genes to find the results of the conservative region.The analysis of rRNA gene copy number shows that the copy number of 5sr RNA and 16 srRNA gene of recombinant mutant strain DOB073 increase by 14 and 5 respectively when compared with that of the original strain DOB150.The copy number of 16 S rRNA gene of recombinant mutant DOB113 is 5 more than that of the original strain DOB150.The copy number of 5srRNA gene of recombinant mutant DOB981 is 1 less than that of the original strain DOB150,and the copy number of 16 s rRNA gene of recombinant mutant DOB981 is 5 more than that of the original strain DOB150.The copy number of 23 srRNA gene of 3 recombinant mutant strains is the same as that of the original strain DOB150.The analysis of base mutation point of rRNA gene shows that the base mutation point of 5srRNA gene of three recombinant mutation strains occur in the 4,107,112,114 base position,and the base mutation point of 5sr RNA gene of DOB073 and DOB113 also occur in the 104 position,the base mutation point of 16 sr RNA gene of three recombinant mutant strains distribute in C1,V1,V2,V4,V6,V7 and V9 region.The 23 sr RNA gene of three recombinant mutants are strongly conserved and only 2-3 base pairs are mutated.The analysis of phylogenetic shows that the 5srRNA and 23 srRNA gene of recombinant mutant strains DOB073 and DOB113 evolve faster than that of recombinant mutant strains DOB981,while the 16 srRNA gene of DOB981 evolve faster than that of DOB073 and DOB113.The analysis of conserved secondary structure of r RNA gene sequences shows that the 16 srRNA gene of DOB073?DOB113?DOB981 and DOB150 totally have nine conserved secondary structures with base positions in 80-120,120-240,240-360,360-480,400-520,640-760,760-880,800-920 and 1420-1540.The 23 srRNA gene of the three recombinant mutant strains and the original strain have 13 conserved secondary structures with the base positions in 40-160,80-200,120-240,720-840 and 1200-1320,1480-1600,1520-1640,2120-2240,2200-2320,2240-2360,2280-2400,2360-2480,2520-2640.We reveals the gene mutation and the molecular mechanism of the DOB strain mediated by ion implantation by analyzing the molecular mechanism of the three rRNA genes of three recombinant DOB strains.It also provides a theoretical and practical basis for the diversity of DOB mediated by ion implantation.Especially,it provides direct molecular evidence for the evolution of prokaryotic microorganisms mediated by low energy ion implantation.