Five to ten serotyqe I Marek’s disease virus (MDV1) strains of different pathotypes were compared for their DNA sequences of gI, gE, pp38 and meq genes. The reference strains were vMDV GA and JM, vvMDV RB1B and Md11(...Five to ten serotyqe I Marek’s disease virus (MDV1) strains of different pathotypes were compared for their DNA sequences of gI, gE, pp38 and meq genes. The reference strains were vMDV GA and JM, vvMDV RB1B and Md11(p16), vv+MDV strains 648A and 584A,vaccine strain CVI988/Rispens; Chinese strains were: v MDV strain N, vvMDV strain G2, vaccine strain 814. Only random aa changes were found in 12 positions within gE of 497 aa among 10 analyzed strains and in 10 positions within gI of 355 aa among 5 strains. There was no relationship found between virus pathotypes and aa changes of both glycoproteins. The aa changes happened in 14 positions within meq of 339 aa among 5 compared strains. But a proline deletion at aa #194 in a proline-rich domain of meq were shared by two vaccine strains CVI988/Rispens and 814, the latter was a non-pathogenic vaccine strain of serotype 1 isolated in 1983 in China. In another hand, vv+MDV strains 648A demonstrated 5 unique aa changes and 4 of them also located in the proline-rich region. The pp38 was very conservative among sequenced 10 strains, there were only two positions at #107 and #109 with aa altered in its 290 aa. All tested MDV1 strains had glutamine at #107, instead, only vaccine CVI988 had arginine at the position and lost its epitope reactive with Mab H19, to which all other tested MDV1 strains were positive. However, CVI988 and vMDV GA shared a Mab T65-recognized epitope when there was glycine at aa#109. It was glutamic acid at aa#109 in all other MDV1 strains which were not reactive with Mab T65. It seems like that there is some relationship between pathotypes and sequences of pp38 and meq, but more strains need to be compared.展开更多
There was a bi-directional promoter between gene 38 kd phosphorylated protein (pp38) gene; 1.8-kb mRNA transcript gene family in the genome of Marek's disease virus (MDV). In this study, enhanced green fluorescenc...There was a bi-directional promoter between gene 38 kd phosphorylated protein (pp38) gene; 1.8-kb mRNA transcript gene family in the genome of Marek's disease virus (MDV). In this study, enhanced green fluorescence protein (EGFP) reporter plamids, pP(pp38)-EGFP; pP(1.8-kb)-EGFP, were constructed under this bi-directional promoter in two directions. The two plasmids were transfected into uninfected chicken embryo fibroblast (CEF), MDV clone rMd5 infected CEF (rMd5-CEF); pp38-deleted derivative rMd5Δpp38 infected CEF (rMd5Δpp38-CEF) respectively. Transfection analysis showed that EGFP was only expressed in rMd5-CEF,; no EGFP could be detected in uninfected CEF or rMd5Δpp38-CEF, implying that pp38 was a factor influencing the activity of the promoter. The pp38-expressing recombinant plasmid pcDNA-pp38 was constructed to co-transfect CEF or rMd5Δpp38-CEF with pP(pp38)-EGFP or pP(1.8-kb)-EGFP. In this case, EGFP could be detected only in rMd5Δpp38-CEF but still not in uninfected CEF, implying that pp38 needs other protein(s) to work together for the complete trans-acting activity. Another MDV gene, 24 kd phosphorylated protein pp24 gene was cloned into pcDNA3.1 as a pp24-expressing recombinant plasmid pcDNA-pp24. When uninfected CEF was co-transfected with pcDNA-pp38, pcDNA-pp24; EGFP expressing plasmids pP(pp38)-EGFP or pP(1.8-kb)-EGFP, the EGFP could be detected. These results indicated that pp38; pp24 could enhance the activity of the promoter when they worked together. DNA mobility shift assay showed that pp38 would bind to the bi-directional promoter with the co-existing of pp24, although neither of them alone influenced mobility of the promoter DNA. All the above suggested that MDV pp38 could transactivate the bi-directional promoter when combined with pp24. The results also indicated that the activity of the promoter in the direction of 1.8-kb mRNA was significantly stronger than that of pp38 direction.展开更多
文摘Five to ten serotyqe I Marek’s disease virus (MDV1) strains of different pathotypes were compared for their DNA sequences of gI, gE, pp38 and meq genes. The reference strains were vMDV GA and JM, vvMDV RB1B and Md11(p16), vv+MDV strains 648A and 584A,vaccine strain CVI988/Rispens; Chinese strains were: v MDV strain N, vvMDV strain G2, vaccine strain 814. Only random aa changes were found in 12 positions within gE of 497 aa among 10 analyzed strains and in 10 positions within gI of 355 aa among 5 strains. There was no relationship found between virus pathotypes and aa changes of both glycoproteins. The aa changes happened in 14 positions within meq of 339 aa among 5 compared strains. But a proline deletion at aa #194 in a proline-rich domain of meq were shared by two vaccine strains CVI988/Rispens and 814, the latter was a non-pathogenic vaccine strain of serotype 1 isolated in 1983 in China. In another hand, vv+MDV strains 648A demonstrated 5 unique aa changes and 4 of them also located in the proline-rich region. The pp38 was very conservative among sequenced 10 strains, there were only two positions at #107 and #109 with aa altered in its 290 aa. All tested MDV1 strains had glutamine at #107, instead, only vaccine CVI988 had arginine at the position and lost its epitope reactive with Mab H19, to which all other tested MDV1 strains were positive. However, CVI988 and vMDV GA shared a Mab T65-recognized epitope when there was glycine at aa#109. It was glutamic acid at aa#109 in all other MDV1 strains which were not reactive with Mab T65. It seems like that there is some relationship between pathotypes and sequences of pp38 and meq, but more strains need to be compared.
基金supported by the National Natural Science Foundation of China(Grant Nos.30300450&30070544).
文摘There was a bi-directional promoter between gene 38 kd phosphorylated protein (pp38) gene; 1.8-kb mRNA transcript gene family in the genome of Marek's disease virus (MDV). In this study, enhanced green fluorescence protein (EGFP) reporter plamids, pP(pp38)-EGFP; pP(1.8-kb)-EGFP, were constructed under this bi-directional promoter in two directions. The two plasmids were transfected into uninfected chicken embryo fibroblast (CEF), MDV clone rMd5 infected CEF (rMd5-CEF); pp38-deleted derivative rMd5Δpp38 infected CEF (rMd5Δpp38-CEF) respectively. Transfection analysis showed that EGFP was only expressed in rMd5-CEF,; no EGFP could be detected in uninfected CEF or rMd5Δpp38-CEF, implying that pp38 was a factor influencing the activity of the promoter. The pp38-expressing recombinant plasmid pcDNA-pp38 was constructed to co-transfect CEF or rMd5Δpp38-CEF with pP(pp38)-EGFP or pP(1.8-kb)-EGFP. In this case, EGFP could be detected only in rMd5Δpp38-CEF but still not in uninfected CEF, implying that pp38 needs other protein(s) to work together for the complete trans-acting activity. Another MDV gene, 24 kd phosphorylated protein pp24 gene was cloned into pcDNA3.1 as a pp24-expressing recombinant plasmid pcDNA-pp24. When uninfected CEF was co-transfected with pcDNA-pp38, pcDNA-pp24; EGFP expressing plasmids pP(pp38)-EGFP or pP(1.8-kb)-EGFP, the EGFP could be detected. These results indicated that pp38; pp24 could enhance the activity of the promoter when they worked together. DNA mobility shift assay showed that pp38 would bind to the bi-directional promoter with the co-existing of pp24, although neither of them alone influenced mobility of the promoter DNA. All the above suggested that MDV pp38 could transactivate the bi-directional promoter when combined with pp24. The results also indicated that the activity of the promoter in the direction of 1.8-kb mRNA was significantly stronger than that of pp38 direction.
