Based On Genome Sequence 6-mer Spectrum Characteristics To Explore Bacterial Relationship

Microorganisms are the masters of the earth's ecosystem,accounting for 50% of all earth's biomass.According to cell structure,they are divided into prokaryotic and eukaryotic microorganisms.Prokaryotic microorganisms also include bacteria and archaea.Bacteria are the most widely distributed in nature and have the largest number of individuals.The life form is an important part of nature's material cycle and is closely related to the survival and evolution of animals and plants.Studying the taxonomy and survival dependence of bacteria has important biological significance for revealing the relationship between species.This article will further study the universality of this evolutionary mechanism in bacteria based on the previous analysis of the genome sequence code mechanism by the research group.We analyzed the phylum Firmicutes with low G+C content and Actinobacteria with high G+C content of gram-positive bacteria,a total of 403 bacterial genome sequences CG1,CG0,TA1 and TA0 subsets 6-mer spectrum The relationship between the characteristic parameters of separability and conservatism and the parameters of each group.The study found that the separability and conservatism values of the 6-mer spectra of the CG1 and TA1 subsets are representative feature parameters in the bacterial genome sequence,and they reflect some of the relevant characteristics of bacterial classification.The separability and conservatism characteristics of the spectrum of CG0 and TA0 subsets are not sensitive to the relationship between bacterial classification.There is a positive correlation between the separability and conservatism of CG1 and TA1 subsets in the bacterial genome with high G+C content or low G+C content.Therefore,we use the separability and conservatism of CG1 to represent CG The strength of selection,the resolution and conservatism of TA1 represent the strength of TA selection.As the intensity of CG selection increases,the intensity of TA selection decreases.The separability and conservatism of CG1 and TA1 are negatively correlated with each other,which is consistent with the previous research conclusions of the research group.Therefore,we propose the hypothesis that the intensity of two independent selections and their mutual inhibition determine the genetic state of the genome sequence.In addition,we also found that the resolution of the CG subset spectrum of the bacterial genome sequence is negatively correlated with the G+C content,and positively correlated with the resolution of the TA subset spectrum,and whether it is TA intensity of independent selection or CG independent The intensity of independent selection has a significant correlation with the genome size,which verifies the conjecture that the correlation between the CG dinucleoside and the intensity of independent selection CG is the closer the relationship,the better the correlation.Finally,we used extreme bacteria with extremely high CG intensity of independent selection(31 types)and extremely high TA intensity of independent selection(30 types)to investigate their biochemical characteristics,and found that bacteria with high CG intensity of independent selection and low TA intensity of independent selection are easy to invade.Infect animals and fungi,while the bacteria with high TA intensity of independent selection and low CG intensity of independent selection are easy to infect plants.It is concluded that the bacteria are easy to infect species with the same evolutionary pattern,which gives a basis for the dependence of bacteria on survival.Our study once again confirmed the universality of the law of independent selection of genome sequence in the genome of prokaryotic bacteria.At the same time,we analyzed the aggregation degree of the species in the graph according to the intensity of CG independent selection and TA independent selection for these 61 kinds of bacteria.The genetic relationship of the species is compared with the?Berger's Bacteria Classification Manual?,and it is found that the level at the genus and above is very consistent,providing a new way of analyzing the genetic relationship of bacteria.