Transcription Analysis Of The Responses Of Porcine Heart To Erysipelothrix Rhusiopathiae,and The Analysis Of Erysipelothrix Rhusiopathiae Comparative Genomics

Erysipelothrix rhusiopathiae(E.rhusiopathiae)is an important zoonotic pathogen,and it can infect pigs and many other mammals.Erysipelothrix rhusiopathiae can also infect people,causing skin lesions.Since 2010,the outbreak of swine erysipelas disease showed a trend in some areas of china.Erysipelothrix rhusiopathiae has caused great economic losses in the pig industry in many countries,and a serious threat to human health.Recently,many pathogens have entered the field of pathogen and host interaction.The Affymetrix porcine whole genome microarray was used to analysis of swine gene expression profiling for immune mechanism of host and provide more accurate and credible basis.5 strains have landed on Genbank,and the research foucs on the study of Single genomic sequencing.In this study,SE38 virulent strain and attenuated strain G4T10 genome were sequenced with the third generation sequencing technology.We hope to reveal the structure and function of the genome of different strains,find new virulence genes,provide molecular basis for the analysis of genetic variation and pathogenic mechanism of E.rhusiopathiae.The main results of this study are summarized as follows:1.Transcription analysis of the responses of porcine heart to Erysipelothrix rhusiopathiaeThe virulent strain SE38,the attenuated strain G4T10 and PBS were infected respectively,and the heart tissues of each group were collected on the fourth day,and the gene chip analysis was carried out.According to this results,virulent SE38 group has a total of 394 transcripts,including 262 transcripts up regulation,132 transcripts down regulation.Compared the G4T10 group with PBS group,the G4T10 group has 130 transcripts,10 transcripts up-regulated and 120 transcripts down-regulated.Differentially expressed(DE)genes of SE38 group VS PBS group were analysed with GO.The 190 annotated GO gene were divided into 24 categories,mainly involved in inflammatory and immune reaction,material and energy metabolism,protein phosphorylation and dephosphorylation.With G4T10 group VS PBS group,41 differentially expressed were divided into 14 categories,mainly involved in transcription,cell division,cell apoptosis,and genes in inflammatory and immune responses were not found.The results of KEGG pathway showed that Chemokine,signaling pathway,NF-kappa B signaling pathway Toll-like receptor signaling pathway and Cell adhesion molecules(CAMs)play an important role in the process of piglets infected with SE38.2.Comparative genomics analysis of Erysipelothrix rhusiopathiaeThe whole genome of the virulent strain SE38 and the attenuated vaccine strain G4T10 were sequenced.These results showed that the similarity of two strains genomic was high.The G4T10 genome was 1770505bp,and the content of GC was 36.5%.The SE38 genome is 1778153bp,larger than that of G4T10 genome,but the GC content of two strains is the same.Through multiple sequence alignment,E.rhusiopathiae is an open pan genomes,and consistent with diversity of growth environment.This result shows E.rhusiopathiae has strong adaptability to environment.In order to analysis E.rhusiopathiae genome dynamics,we study the gene evolution of different strains.The results showed that a common ancestor of all strains contained 1260 genes.In the formation process,SE38 lost many genes(1006 genes)in the near future,gene of SE38 strain missing number were more than SY1027,G4T10 and Fujisawa,but at the same time 1048 genes were obtained through horizontal transfer,a large number of gene loss and gain may lead to SE38 and other strains produced differences.The transcription RNA of SE38 and G4T10 were sequenced.In G4T10,10 5 ’UTRs,10 3’UTRs,248 new transcripts and 365 polycistronic antisons were identified.In SE38,6 5 ’UTRs,14 3’ UTRs,146 new transcripts and 363 polycistrons were identified.Comparing these two strains,we found that the two strains were in the same region of the genome,but were significantly different for transcriptional control.Through the analysis of transcriptional level,there are many differences in the cis-antisonsIn the VFDB database,the potential virulence factor was predicted,and 20 virulence related factors were predicted,which belonged to adhesion,secretion and iron,but did not identify the virulence factor about toxin.Based on the results of the above genome sequence,the C terminus of SpaA of the SE38 was 2 more GW repeat than the C terminus of the G4T10 strain.And the missing part is in the first,second and third parts of the repeat sequence.And we construct deletion of the SpaA sequence in the SE38 strain,consistent with the SpaA gene of G4T10.Compared with the wild-type strain,the cell adhesion ability of mutant strain(ΔSE38)was decreased 2 times,and virulence was decreased 40%.The SpaA gene of SE38 strain and SpaA gene of ΔSE38 were respectively expressed,and compared the adhesion ability to cell.We found that the adhesion ability of SE38 SpaA was higher than that ofΔSE38 SpaA protein.It was proved that deletion of repeat sequence of C terminal second and third of SpaA gene could decrease the ability of SpaA protein adhesion to PIEC cells.