This study aims to screen epitope antigens targeting the receptor binding domain(RBD)of porcine epidemic diarrhea virus(PEDV)based on its amino acid sequence(GenBank accession number:AKN45969.1),prepare PEDV RBD polyclonal antibody,and perform their identification.Bioinformatics analysis software was used to predict the potential antigenic epitopes of PEDV RBD and sequence comparison with porcine coronavirus strains was performed,the selected dominant antigen epitopes were then conjugated with keyhole limpet hemocyanin(KLH),to synthesize pep-tides directly and immunize mice to generate specific antibody,Western blot technique and indirect immunofluorescence assay were utilized to identify the specificity of the antibodies,and indirect ELISA method was further applied to determine the antibody potency.Results showed the selected PEDV RBD dominant epitope sequence shared 100％similarity with 18 other PEDV strains,while exhibiting low sequence similarity with 11 TGEV strains(27.8％—29.3％)and 16 PDCoV strains(10.5％—13.4％),indicating good epitope conservation.Western blot showed that the specificity of the prepared peptide antibody specifically recognized the PEDV RED protein overexpressed in Ex-pi293F cells and overexpressed in baculovirus system,and at the same time,the antibody was still able to detect the PEDV S protein expressed in PEDV-infected Vero cells at a 1∶2 000 dilution,while it did not react with TGEV-and PDCoV-infected ST cells,indicating that the good specificity of the peptide antibody.ELISA revealed that the potency of specific antibodies in mouse serum could reach up to 1∶25 600.The above results indicate that bioinformatics techniques were suc-cessfully utilized to predict antigenic epitopes of PEDV RBD protein,and specific PEDV RBD pep-tide antibodies were prepared.

This study aims to screen epitope antigens targeting the receptor binding domain(RBD)of porcine epidemic diarrhea virus(PEDV)based on its amino acid sequence(GenBank accession number:AKN45969.1),prepare PEDV RBD polyclonal antibody,and perform their identification.Bioinformatics analysis software was used to predict the potential antigenic epitopes of PEDV RBD and sequence comparison with porcine coronavirus strains was performed,the selected dominant antigen epitopes were then conjugated with keyhole limpet hemocyanin(KLH),to synthesize pep-tides directly and immunize mice to generate specific antibody,Western blot technique and indirect immunofluorescence assay were utilized to identify the specificity of the antibodies,and indirect ELISA method was further applied to determine the antibody potency.Results showed the selected PEDV RBD dominant epitope sequence shared 100％similarity with 18 other PEDV strains,while exhibiting low sequence similarity with 11 TGEV strains(27.8％—29.3％)and 16 PDCoV strains(10.5％—13.4％),indicating good epitope conservation.Western blot showed that the specificity of the prepared peptide antibody specifically recognized the PEDV RED protein overexpressed in Ex-pi293F cells and overexpressed in baculovirus system,and at the same time,the antibody was still able to detect the PEDV S protein expressed in PEDV-infected Vero cells at a 1∶2 000 dilution,while it did not react with TGEV-and PDCoV-infected ST cells,indicating that the good specificity of the peptide antibody.ELISA revealed that the potency of specific antibodies in mouse serum could reach up to 1∶25 600.The above results indicate that bioinformatics techniques were suc-cessfully utilized to predict antigenic epitopes of PEDV RBD protein,and specific PEDV RBD pep-tide antibodies were prepared.

The SYBR Green Ⅰ real-time fluorescence quantitative PCR detection method was used to determine the prevalence of Japanese encephalitis virus(JEV)in mosquito vectors and cattle se-rum samples in Xinjiang.The E gene fragment of the JEV strain was amplified by PCR,cloned into a pEASY-Blunt vector,produced as a recombinant plasmid,and its sensitivity,specificity and re-producibility were verified.Between 2021 and 2022,serum samples were taken in the regions of Hami,Altay,Ili,Aksu,and Kashi in order to monitor the prevalence of JEV in livestock in Xin-jiang.The positive rate was discovered and evaluated using the established detection method.The established detection method showed a good linear relationship,and the detection interval was 4.03X102-4.03×109 copies/pL.The correlation coefficient was 0.995,the slope was-3.431,and the extreme value of the lower limit of sensitivity was 4.03 × 102 copies/pL.This method has no specific amplification for Zika virus(ZIKV)and Dengue virus(DENV).The intra group coefficient of variation of reproducibility was 0.53％-1.27％,and the inter group coefficient of variation was 0.48％-1.43％.Using this method to detect serum samples from livestock in Xinjiang from 2021 to 2022,the total positive rate was 3.28％,with positive detection rates in horses,cows,and sheep being 2.35％,6.77％,and 3.74％respectively,the virus was identified as Type Ⅰ JEV.A SYBR Green Ⅰ real-time PCR method for the detection of genotype 1 JEV was established.JEV was de-tected in the serum of horses,cattle and sheep in Xinjiang,with a total positive rate of 3.11％.

The envelope gene gp85 of ev/J,a new family of endogenous avian retroviral sequences identified recently, has the most extensive nucleotide sequence identity ever described with ALV-J avian ieukosis virus. This report described expression of ev/J envelope gene gp85 derived from commercial meat-type chicken using the Invitrogen Bac-to-Bac baculovirus expression system. The antigenicity and immunoreactivity of the recombinant endogenous gp85 gene product (SU) were analyzed by indirect immunofluorescence, Western blot, indirect and blocking Enzyme-Linked ImmunoSorbent Assay (ELISA) using JE9 monoclonal antibody (MAb) against the envelope protein of ALV-J (ADOL-4817), positive mouse antiserum against the ev/J gp85 SU and sera from chicken naturally infected with ALV-J. The results showed that the ev/J gp85 SU can bind specifically to JE9 MAb and antiserum from chicken naturally infected with ALV-J, and the binding reactivity between exogenous ALV-J gp85 SU and natural positive chicken serum against exogenous ALV-J can be blocked by positive mouse serum against the ev/J gp85 SU. It is concluded that recombinant endogenous gp85 gene product (SU) has close immunological relatedness to the envelope protein of exogenous ALV-J (ADOL-4817 and IMC<,10200> strain).