Differences In Pathogenicity And Adult Gene Expression Profiles Of Schistosoma Japonicum In Hilly And Marshland Regions Of Anhui Province

Objective: To study the differences in pathogenicity and adult gene expression profiles of Schistosoma japonicum in hilly regions and marshland regions of Anhui Province,and explore the reasons for the "separation phenomenon" of S.japonicum infection rates among humans,animals and snails in the hilly regions of the province so as to provide a scientific basis for the precise control of schistosomiasis.Methods: Oncomelania hupensis were collected from Shitai County,a typical hilly region in Anhui Province,and Susong County,a typical marshland region.The snails were screened for infectious snails by the sporocyst method.The cercariae of S.japonicum were collected,and C57BL/6 mice were infected with the cercariae from the two sources.The serum of mice was collected every week after infection to detect the levels of IgM and IgG antibodies of S.japonicum in the serum;and 44 days after infection,the mice were dissected to compare the serum medium AST and ALT content,the number of worms,the number of eggs deposited in the liver,the area of granulomas in the liver.In addition,high-throughput sequencing was used to sequence the transcriptomes of two groups of S.japonicum adults.And alternative splicing analysis was performed on the genes of each group of samples.Find out the differentially expressed genes between the adults of the two places,annotate and analyze them through GO and KEGG databases,and carry out functional enrichment analysis of the differentially expressed genes to compare the differences between the two strains.Finally,q RT-PCR was used to verify the transcription level of genes identified by RNA-seq.Result:(1)After infecting C57BL/6 mice with S.japonicum cercariae from the hilly region and marshland region of Anhui Province,the changes of S.japonicum antibody IgM and IgG in the serum of the two groups of mice were basically the same;the content of AST and ALT in serum,the number of total worms in the two groups of mice,the number of male and female symbiosis pairs,the number of unsyzygous males,the number of eggs deposited in the liver per gram and the areas of granulomas on a single egg in the liverwere not significantly different(t=1.654,P=0.115;P=0.096;t=0.877,P=0.392;t=1.129,P=0.280;t=0.069,P=0.946;t=1.821,P=0.085;t=0.081,P=0.936).(2)High-throughput sequencing was used to sequence the transcriptomes of adult S.japonicum from the hilly region and marshland region of Anhui Province,respectively.One exon alternative splicing is the most frequent type in all worm samples.584 differentially expressed genes were screened between the two groups of females,of which 344 genes were up-regulated in the females of the Susong group,and 240 genes were upregulated in the females of the Shitai group;1 598 differentially expressed genes were screened between the two groups of males,of which 1 160 genes were up-regulated in males of Susong group and 438 genes were up-regulated in males of Shitai group.GO enrichment analysis showed that the down-regulated genes between the two groups of females were related to cell membrane composition and L-arginine transport,and the upregulated genes between the two groups of females were mainly related to the biological processes involved;The down-regulated genes between the two groups of males were mainly related to molecular functions,and the up-regulated genes between the two groups of males were mainly related to the components of the cell membrane and the activity of G protein-coupled peptide receptors.After GO and KEGG enrichment analysis,it was found that the two groups were differentially expressed genes among females were significantly enriched in the function of arginine transport and metabolism,and related genes were highly expressed in females from Shitai County in the hilly region.The results of q RT-PCR validation were consistent with the RNA-seq data.Conclusion: After infection of mice with S.japonicum cercariae from hilly regions and marshland regions of Anhui Province,there was no significant difference in pathogenicity in a short period of time,but the gene expression profiles of S.japonicum adults from the two sources were significantly different,this genetic differentiation may be one of the reasons for the "separation phenomenon" of S.japonicum infection rates among humans,animals and snails in the hilly regions of the province.