scholarly journals Genetic evolution of Marek's disease virus in vaccinated poultry farms

2021 ◽  
pp. 1342-1353
Author(s):  
Nahed Yehia ◽  
Hemat S. El-Sayed ◽  
Sabry E. Omar ◽  
Ahmed Erfan ◽  
Fatma Amer
Keyword(s):  
Disease Virus ◽  
Marek's Disease Virus ◽  
Marek's Disease ◽  
Economic Losses ◽  
Neoplastic Disease ◽  
Marek’S Disease Virus ◽  
Marek’S Disease ◽  
Gallid Herpesvirus 2 ◽  
Highly Virulent ◽  
Meq Gene

Background and Aim: The Marek's disease virus (MDV) is a neoplastic disease causing serious economic losses in poultry production. This study aimed to investigate MDV occurrence in poultry flocks in the Lower Egypt during the 2020 breakout and genetically characterized Meq, gL, and ICP4 genes in field strains of MDV. Materials and Methods: Forty samples were collected from different breeds from eight Egyptian governorates in 2020. All flocks had received a bivalent vaccine (herpesvirus of turkey FC-126 + Rispens CVI988). However, weight loss, emaciation, reduced egg production, paralysis, and rough/raised feather follicles occurred. Samples were collected from feather follicles, liver, spleen, and nerve tissue for diagnosis by polymerase chain reaction. MDV genetic characterization was then performed by sequencing the Meq, gL, and ICP4 genes of five positive samples representing different governorates and breeds. Results: A total of 28 samples were positive for MDV field strains, while two were related to MDV vaccinal strains. All samples tested negative for ALV (A, B, C, D, and J) and REV. Phylogenetic analysis of the Meq gene of sequenced samples revealed that all MDVs were related to the highly virulent European viruses (Gallid herpesvirus 2 ATE and PC12/30) with high amino acid (A.A.) identity 99.2-100%. Alternatively, there was low A.A. identity with the vaccine strains CVI988 and 3004 (up to 82.5%). These results indicate that further investigation of the efficacy of current Egyptian vaccines is required. The Egyptian strains also harbor a specific mutation, allowing clustering into two subgroups (A and B). By mutation analysis of the Meq gene, the Egyptian viruses in our study had R101K, P217A, and E263D mutations present in all Egyptian viruses. Furthermore, R176A and T180A mutations specific to our strains contributed to the high virulence of highly virulent strains. There were no mutations of the gL or ICP4 genes. Conclusion: Further studies should evaluate the protection contributed by current vaccines used in Egypt.

scholarly journals Characterization of Marek’s disease virus and phylogenetic analyses of meq gene from an outbreak in poultry in Meghalaya of Northeast India

VirusDisease ◽  
2018 ◽  
Vol 29 (2) ◽  
pp. 167-172 ◽  
Author(s):  
Kekungu-u Puro ◽  
Uttaran Bhattacharjee ◽  
Samprity Baruah ◽  
Arnab Sen ◽  
Samir Das ◽  
...  
Keyword(s):  
Disease Virus ◽  
Phylogenetic Analyses ◽  
Northeast India ◽  
Marek's Disease Virus ◽  
Marek's Disease ◽  
Marek’S Disease Virus ◽  
Marek’S Disease ◽  
Meq Gene

Isolation of a Field Marek’s Disease Virus with Acute Oncogenicity from Tibetan Chickens in China and Sequence Analysis of Oncogenic Genes

2011 ◽  
Vol 343-344 ◽  
pp. 538-544
Author(s):  
Ming Xing Tian ◽  
Rui Deng ◽  
Yang Zhao ◽  
Min Li ◽  
San Jie Cao ◽  
...  
Keyword(s):  
Disease Virus ◽  
Challenge Test ◽  
Point Mutations ◽  
Repeated Sequence ◽  
Marek's Disease Virus ◽  
Marek's Disease ◽  
Marek’S Disease Virus ◽  
Marek’S Disease ◽  
Specific Pathogen ◽  
Meq Gene

A field Marek’s disease virus (MDV), named as BY strain, was firstly isolated from Tibetan chickens in Sichuan province, China, by method of co-cultivation of the lymphocytes with duck embryo fibroblasts (DEF). Analysis of the oncogenic genes showed that there were 2 copies of 132-bp repeated sequence in long terminal repeat of the BY strain, The nucleotide and amino acid sequence identities of Meq gene of BY strain with other prevalent MDV strains in China were 97.6-100.0% and 98.8-100.0%, respectively, and some point mutations assumed to be relevant to the oncogenecity of MDV also existed in the Meq gene of BY strain. The result of animal challenge test on specific-pathogen-free (SPF) chickens showed lymphomas may occur in a variety of organs as early as 18 days post challenge, and the rate of tumor occurrences and mortalities reached to 73.33% and 66.67% in HVT immunized chickens, respectively. In conclusion, an MDV strain charac-terized of acute oncogenicity was isolated from Tibetan chickens in China, though there were no obvious difference between the oncogenic genes of this strain and other virulent MDV strains isolated in China in recent years.

scholarly journals MicroRNAs 221 and 222 target p27Kip1 in Marek's disease virus-transformed tumour cell line MSB-1

2009 ◽  
Vol 90 (5) ◽  
pp. 1164-1171 ◽  
Author(s):  
Luke S. Lambeth ◽  
Yongxiu Yao ◽  
Lorraine P. Smith ◽  
Yuguang Zhao ◽  
Venugopal Nair
Keyword(s):  
Cell Cycle ◽  
Cell Line ◽  
Disease Virus ◽  
Expression Profiles ◽  
Marek's Disease Virus ◽  
Marek's Disease ◽  
Tumour Cell Line ◽  
Neoplastic Disease ◽  
Marek’S Disease Virus ◽  
Marek’S Disease

MicroRNAs (miRNAs) are a class of short RNAs that function as post-transcriptional suppressors of protein expression and are involved in a variety of biological processes, including oncogenesis. Several recent studies have implicated the involvement of miR-221 and miR-222 in tumorigenesis as these miRNAs are upregulated in a number of cancers and affect the expression of cell cycle regulatory proteins such as the cyclin-dependent kinase (cdk) inhibitor p27Kip1. Marek's disease virus (MDV) is a highly oncogenic herpesvirus that affects poultry, causing acute neoplastic disease with lymphomatous lesions in several organs. MDV-encoded oncogenes such as Meq are directly implicated in the neoplastic transformation of T cells and have been well studied. More recently, however, the involvement of both host and virus-encoded miRNAs in the induction of MD lymphomas is being increasingly recognized. We analysed the miRNA expression profiles in the MDV-transformed lymphoblastoid cell line MSB-1 and found that endogenous miRNAs miR-221 and miR-222 were significantly upregulated. Demonstration of the conserved binding sites for these miRNAs in the chicken p27Kip1 3′-untranslated region sequence and the repression of luciferase activity of reporter constructs indicated that miR-221 and miR-222 target p27Kip1 in these cells. We also found that overexpression of miR-221 and miR-222 decreased p27Kip1 levels and that treatment with retrovirally expressed antagomiRs partially alleviated this suppression. These data show that an oncogenic herpesvirus, as in the case of many cancers, can exploit the miRNA machinery for suppressing cell cycle regulatory molecules such as p27Kip1 in the induction and progression of T-cell lymphomas.

scholarly journals MicroRNA Profile of Marek's Disease Virus-Transformed T-Cell Line MSB-1: Predominance of Virus-Encoded MicroRNAs

2008 ◽  
Vol 82 (8) ◽  
pp. 4007-4015 ◽  
Author(s):  
Yongxiu Yao ◽  
Yuguang Zhao ◽  
Hongtao Xu ◽  
Lorraine P. Smith ◽  
Charles H. Lawrie ◽  
...  
Keyword(s):  
T Cell ◽  
Cell Line ◽  
Disease Virus ◽  
Northern Blotting ◽  
Marek's Disease Virus ◽  
Marek's Disease ◽  
Neoplastic Disease ◽  
Marek’S Disease Virus ◽  
Marek’S Disease ◽  
Microrna Profile

ABSTRACT Research over the last few years has demonstrated the increasing role of microRNAs (miRNAs) as major regulators of gene expression in diverse cellular processes and diseases. Several viruses, particularly herpesviruses, also use the miRNA pathway of gene regulation by encoding their own miRNAs. Marek's disease (MD) is a widespread lymphomatous neoplastic disease of poultry caused by the highly contagious Marek's disease virus type 1 (MDV-1). Recent studies using virus-infected chicken embryo fibroblasts have identified at least eight miRNAs that map to the RL/RS region of the MDV genome. Since MDV is a lymphotropic virus that induces T-cell lymphomas, analysis of the miRNA profile in T-cell lymphoma would be more relevant for examining their role in oncogenesis. We determined the viral and host miRNAs expressed in MSB-1, a lymphoblastoid cell line established from an MDV-induced lymphoma of the spleen. In this paper, we report the identification of 13 MDV-1-encoded miRNAs (12 by direct cloning and 1 by Northern blotting) from MSB-1 cells. These miRNAs, five of which are novel MDV-1 miRNAs, map to the Meq and latency-associated transcript regions of the MDV genome. Furthermore, we show that miRNAs encoded by MDV-1 and the coinfected MDV-2 accounted for >60% of the 5,099 sequences of the MSB-1 “miRNAome.” Several chicken miRNAs, some of which are known to be associated with cancer, were also cloned from MSB-1 cells. High levels of expression of MDV-1-encoded miRNAs and potentially oncogenic host miRNAs suggest that miRNAs may have major roles in MDV pathogenesis and neoplastic transformation.

scholarly journals Difference in the meq Gene between Oncogenic and Attenuated Strains of Marek's Disease Virus Serotype 1.

2000 ◽  
Vol 62 (3) ◽  
pp. 287-292 ◽  
Author(s):  
Sung-Il LEE ◽  
Michihiro TAKAGI ◽  
Kazuhiko OHASHI ◽  
Chihiro SUGIMOTO ◽  
Misao ONUMA
Keyword(s):  
Disease Virus ◽  
Marek's Disease Virus ◽  
Marek's Disease ◽  
Marek’S Disease Virus ◽  
Marek’S Disease ◽  
Virus Serotype ◽  
Serotype 1 ◽  
Meq Gene

scholarly journals Molecular epidemiology of Marek’s disease virus in central Pennsylvania, USA

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Andrew S Bell ◽  
David A Kennedy ◽  
Matthew J Jones ◽  
Christopher L Cairns ◽  
Utsav Pandey ◽  
...  
Keyword(s):  
Disease Virus ◽  
Haplotype Diversity ◽  
Extended Period ◽  
Marek's Disease Virus ◽  
Marek's Disease ◽  
Marek’S Disease Virus ◽  
Marek’S Disease ◽  
Evolutionary Potential ◽  
Gallid Herpesvirus 2 ◽  
Poultry Farms

AbstractThe evolution of Marek’s disease virus (MDV, Gallid herpesvirus 2) has threatened the sustainability of poultry farming in the past and its continued evolution remains a concern. Genetic diversity is key to understanding evolution, yet little is known about the diversity of MDV in the poultry industry. Here, we investigate the diversity of MDV on 19 Pennsylvanian poultry farms over a 3-year period. Using eight polymorphic markers, we found that at least twelve MDV haplotypes were co-circulating within a radius of 40 km. MDV diversity showed no obvious spatial clustering nor any apparent clustering by bird line: all of the virus haplotypes identified on the commercial farms could be found within a single, commonly reared bird line. On some farms, a single virus haplotype dominated for an extended period of time, while on other farms the observed haplotypes changed over time. In some instances, multiple haplotypes were found simultaneously on a farm, and even within a single dust sample. On one farm, co-occurring haplotypes clustered into phylogenetically distinct clades, putatively assigned as high and low virulence pathotypes. Although the vast majority of our samples came from commercial poultry farms, we found the most haplotype diversity on a noncommercial backyard farm experiencing an outbreak of clinical Marek’s disease. Future work to explore the evolutionary potential of MDV might therefore direct efforts toward farms that harbor multiple virus haplotypes, including both backyard farms and farms experiencing clinical Marek’s disease.

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