An exogenous avian leukosis virus (ALV) strain SDAU09C1 was isolated in DF-1 cells from one of 240 imported 1-day-old white meat-type grand parent breeder chicks. Inoculation of SDAU09C1 in ALV-free chickens induced a...An exogenous avian leukosis virus (ALV) strain SDAU09C1 was isolated in DF-1 cells from one of 240 imported 1-day-old white meat-type grand parent breeder chicks. Inoculation of SDAU09C1 in ALV-free chickens induced antibody reactions specific to subgroup A or B. But gp85 amino acid sequence comparisons indicated that SDAU09C1 fell into subgroup A; it had homology of 88.8%-90.3% to 6 reference strains of subgroup A, much higher compared to other subgroups including subgroup B. This is the first report for ALV of subgroup A isolated from imported breeders.展开更多
Rapid diagnostic methods for classifying avian leukosis subgroups in the field were needed for routine, large-scale screening. As a first step in method development, we inserted the avian leukosis virus subgroup A （A...Rapid diagnostic methods for classifying avian leukosis subgroups in the field were needed for routine, large-scale screening. As a first step in method development, we inserted the avian leukosis virus subgroup A （ALV-A） env gene into plasmid pcDNA3.1/Zeo （＋） and used this construct to transfect DF-1 cells. Zeocin-resistant cells were obtained after 2 weeks of zeocin selection. Then, the cells were analyzed using PCR, immunofluorescence, and Western blot for expression of the envA-encoded envelope protein after 30 serial passages. The DF-1/A cell line was completely resistant to 104 TCIDso/0.1 mL （50% tissue culture infective dose）ALV-A and was partially resistant to 10~ TCIDs0/0.1 mL ALV-A viral particles. By comparing the DF-1/A and DF-1 cell lines, an ALV-A isolate was identified using a gag-specific ELISAfor capsid protein p27. Thus, we established a DF-1/A cell line that was resistant to ALV-A infection. This cell line will be useful as a diagnostic tool.展开更多
A subgroup J avian leukosis virus (AVL-J), designated as ZH-08, was isolated from a breeder flock in Guangdong province with a novel hemangioma case. The identification results of ELISA test, PCR and immunofluoresecen...A subgroup J avian leukosis virus (AVL-J), designated as ZH-08, was isolated from a breeder flock in Guangdong province with a novel hemangioma case. The identification results of ELISA test, PCR and immunofluoresecence assay (IFA) specific for ALV-J were all positive. Based on the public full-length proviral genome sequence of ALV-J prototype strain HPRS-103, three pairs of primers were synthesized. The full-length proviral genome sequence of ZH-08 isolate is 7597 bp, which has a little difference with that of published full-length genome sequences, but its organization corresponds with typical retroviral genome structure; and known oncogenes were not included in its genome. According to the gp85 sequence comparison of ZH-08 isolate with those of the other reference strains in China and abroad, the highest similarity (93.7%) was with the YZ9901 isolate. Phylogenetic analysis, based on the gp85 gene, showed that the ZH-08 isolated here had the closest linkage to the SD07LK1 isolate. This study provides the basis for the biological characterization and pathogenesis research of the ZH-08 isolate.展开更多
Blood samples were collected from a local strain of chickens associated with serious tumor cases in Shandong Province. The samples were inoculated into chicken embryo fibroblast and DF-1 cells for virus isolation and ...Blood samples were collected from a local strain of chickens associated with serious tumor cases in Shandong Province. The samples were inoculated into chicken embryo fibroblast and DF-1 cells for virus isolation and identification, respectively. The inoculated cells were screened for three common chicken tumor viruses. Nine strains of avian leukosis virus subgroup J （ALV-J） were identified, and were designated LY1201-LYI209. The env gene from the LY1201 strain was amplified and cloned. All nine resultant env clones （clones 01-09） were sequenced, and the gp85 and gp37 amino acid regions were subjected to homology analysis. Clones 01 and 03 had 10 amino acid deletions in the gp85 region compared to the other seven clones, suggesting that at least two quasispecies with obvious mutations coexist in the same field strain. Among these nine clones, three had identical gp85 and gp37 sequences, and were recognized as the dominant LY1201 quasispecies. The amino acid sequence homology of gp37 and gp85 among the nine clones was 98.5%-100.0% and 96.6%-100.0% respectively, suggesting that the gp85 region of the env gene can better display the quasispecies diversity of ALV-J than gp37.展开更多
Subgroup J avian leukosis virus(ALV-J) is a highly oncogenic retrovirus that has been devastating the global poultry industry since the late 1990s. The major infection model of ALV-J is vertical transmission, which is...Subgroup J avian leukosis virus(ALV-J) is a highly oncogenic retrovirus that has been devastating the global poultry industry since the late 1990s. The major infection model of ALV-J is vertical transmission, which is responsible for the congenital infection of progeny from generation to generation. Increasing evidence has suggested that extracellular vesicles(EVs) derived from virus-infected cells or biological fluids have been thought to be vehicles of transmission for viruses. However, the role of EVs in infection and transmission of ALV-J remains obscure. In the present study, semen extracellular vesicles(SE) were isolated and purified from ALV-J-infected rooster seminal plasma(SE-ALV-J), which was shown to contain ALV-J genomic RNA and partial viral proteins, as determined by RNA sequencing, reverse transcription-quantitative PCR and Western blotting. Furthermore, SE-ALV-J was proved to be able to transmit ALV-J infection to host cells and establish productive infection.More importantly, artificial insemination experiments showed that SE-ALV-J transmitted ALV-J infection to SPF hens, and subsequently mediated vertical transmission of ALV-J from the SPF hens to the progeny chicks. Taken together, the results of the present study suggested that ALV-J utilized host semen extracellular vesicles as a novel means for vertical transmission, enhancing our understanding on mechanisms underlying ALV-J transmission.展开更多
基金supported by a grant from Shandong province and a grant (200803019) from the Ministry of Agriculturesupported by a grant from Shandong province and a grant (20080019) from the Ministry of Agriculture
文摘An exogenous avian leukosis virus (ALV) strain SDAU09C1 was isolated in DF-1 cells from one of 240 imported 1-day-old white meat-type grand parent breeder chicks. Inoculation of SDAU09C1 in ALV-free chickens induced antibody reactions specific to subgroup A or B. But gp85 amino acid sequence comparisons indicated that SDAU09C1 fell into subgroup A; it had homology of 88.8%-90.3% to 6 reference strains of subgroup A, much higher compared to other subgroups including subgroup B. This is the first report for ALV of subgroup A isolated from imported breeders.
基金The work was founded by the National Key R&D Program of China(2016YFD0501606)the Public Industry Research Program,the Ministry of Agriculture of China(201203055)+2 种基金the Program of Science and Technology Development of Guangdong Province,China(2015A020209145)the China Meat-Type Chicken Research System(CARS-42-G09)the Modern Agriculture Talents Support Program,Ministry of Agriculture of China([2012] no.160)
文摘Rapid diagnostic methods for classifying avian leukosis subgroups in the field were needed for routine, large-scale screening. As a first step in method development, we inserted the avian leukosis virus subgroup A （ALV-A） env gene into plasmid pcDNA3.1/Zeo （＋） and used this construct to transfect DF-1 cells. Zeocin-resistant cells were obtained after 2 weeks of zeocin selection. Then, the cells were analyzed using PCR, immunofluorescence, and Western blot for expression of the envA-encoded envelope protein after 30 serial passages. The DF-1/A cell line was completely resistant to 104 TCIDso/0.1 mL （50% tissue culture infective dose）ALV-A and was partially resistant to 10~ TCIDs0/0.1 mL ALV-A viral particles. By comparing the DF-1/A and DF-1 cell lines, an ALV-A isolate was identified using a gag-specific ELISAfor capsid protein p27. Thus, we established a DF-1/A cell line that was resistant to ALV-A infection. This cell line will be useful as a diagnostic tool.
基金supported by National Science Foundation of Guangdong Province(Grant No.8151064201000065)Special Fund for Agro-scientific Research in the Public Interest(200803019)to Weisheng Cao+2 种基金NSFC-Guangdong Union Foundation(GrantNo.U0831002)National Natural Science Foundation(Grant No.30771612)Key Program of Science and Technology Development of Guangdong Province(Grant No.2009A020101006)to Ming Liao
文摘A subgroup J avian leukosis virus (AVL-J), designated as ZH-08, was isolated from a breeder flock in Guangdong province with a novel hemangioma case. The identification results of ELISA test, PCR and immunofluoresecence assay (IFA) specific for ALV-J were all positive. Based on the public full-length proviral genome sequence of ALV-J prototype strain HPRS-103, three pairs of primers were synthesized. The full-length proviral genome sequence of ZH-08 isolate is 7597 bp, which has a little difference with that of published full-length genome sequences, but its organization corresponds with typical retroviral genome structure; and known oncogenes were not included in its genome. According to the gp85 sequence comparison of ZH-08 isolate with those of the other reference strains in China and abroad, the highest similarity (93.7%) was with the YZ9901 isolate. Phylogenetic analysis, based on the gp85 gene, showed that the ZH-08 isolated here had the closest linkage to the SD07LK1 isolate. This study provides the basis for the biological characterization and pathogenesis research of the ZH-08 isolate.
基金financially supported by a special grant from Ministry of Agriculture of China in 2012
文摘Blood samples were collected from a local strain of chickens associated with serious tumor cases in Shandong Province. The samples were inoculated into chicken embryo fibroblast and DF-1 cells for virus isolation and identification, respectively. The inoculated cells were screened for three common chicken tumor viruses. Nine strains of avian leukosis virus subgroup J （ALV-J） were identified, and were designated LY1201-LYI209. The env gene from the LY1201 strain was amplified and cloned. All nine resultant env clones （clones 01-09） were sequenced, and the gp85 and gp37 amino acid regions were subjected to homology analysis. Clones 01 and 03 had 10 amino acid deletions in the gp85 region compared to the other seven clones, suggesting that at least two quasispecies with obvious mutations coexist in the same field strain. Among these nine clones, three had identical gp85 and gp37 sequences, and were recognized as the dominant LY1201 quasispecies. The amino acid sequence homology of gp37 and gp85 among the nine clones was 98.5%-100.0% and 96.6%-100.0% respectively, suggesting that the gp85 region of the env gene can better display the quasispecies diversity of ALV-J than gp37.
基金supported by the Key Research and Development Program of Guangdong Province (2020B020222001)the National Natural Science Foundation of China (Grant Nos. 31972659, 31902252, 31672564, 31602053)+5 种基金Guangdong Basic and Applied Basic Research Foundation (2019A1515012006)Natural Science Foundation of Guangdong Province (2018B030315009)China Postdoctoral Science Foundation (2019M652922)the Special Project of National Modern Agricultural Industrial Technology System (CARS-41)the Chief expert Project of Agricultural Industry Technology system in Guangdong Province (2019KJ128)the support of Instrumental Anlysis&Research Center of South China Agriculture University。
文摘Subgroup J avian leukosis virus(ALV-J) is a highly oncogenic retrovirus that has been devastating the global poultry industry since the late 1990s. The major infection model of ALV-J is vertical transmission, which is responsible for the congenital infection of progeny from generation to generation. Increasing evidence has suggested that extracellular vesicles(EVs) derived from virus-infected cells or biological fluids have been thought to be vehicles of transmission for viruses. However, the role of EVs in infection and transmission of ALV-J remains obscure. In the present study, semen extracellular vesicles(SE) were isolated and purified from ALV-J-infected rooster seminal plasma(SE-ALV-J), which was shown to contain ALV-J genomic RNA and partial viral proteins, as determined by RNA sequencing, reverse transcription-quantitative PCR and Western blotting. Furthermore, SE-ALV-J was proved to be able to transmit ALV-J infection to host cells and establish productive infection.More importantly, artificial insemination experiments showed that SE-ALV-J transmitted ALV-J infection to SPF hens, and subsequently mediated vertical transmission of ALV-J from the SPF hens to the progeny chicks. Taken together, the results of the present study suggested that ALV-J utilized host semen extracellular vesicles as a novel means for vertical transmission, enhancing our understanding on mechanisms underlying ALV-J transmission.
