Sequencing Analysis of Genomic Repeat Regions of Three Marek’s Disease Virus Isolates
|School||Jilin Agricultural University|
|Keywords||Marek's disease virus Genome duplication District Sequence analysis Pathogenicity|
Marek's disease (Marek's disease, MD) by Marek's disease virus (Marek's disease virus, MDV) caused by a kind of lymphoproliferative malignant disease characterized by the poultry industry causing huge economic losses. While the disease is currently the only available vaccine against neoplastic diseases. According serological properties, MDV includes three serotypes: MDV-1, MDV-2 and HVT, only serotype 1 (MDV-1) is pathogenic. MDV different strains pathogenic to chickens vary widely, and although many of the immunization through the prevention and control strategies to combat MD, in the most recent decades, MDV virulence is still showing growing trend. Studies have shown that pandemic strains are more virulent in the direction to evolve, but the molecular basis of evolution is still unknown, and therefore, virulence associated genes, will contribute to a better understanding of MDV-induced disease mechanisms. MDV genome of about 170-180 kb, from a single area and duplication zone. Repeat region including internal and terminal repeat repeat region, both for the inverted repeat sequence. Internal duplication length of about 24kb, including long internal repeats (Long internal repeat region, IRL) and short internal repeats (Short internal repeat region, IRS), the majority concentrated in the region with the viral replication and cause tumors and other related genes, such as Meq gene, virus-encoded telomeric RNA, vIL-8, RLORF4, RLORF12, ICP4, etc., and most of MDV-1 gene is specific. Analysis of the primary structure of the gene region of the pathogenesis of MDV and genetic variation study has important significance. This study is based MDVGA strain genome sequence, were designed and synthesized 12 pairs of primers, the domestic three MDV-1 strains in genomic repeats were fragment amplification and cloning, sequence through the determination of stitching and analysis, and Log in GenBank at home and abroad with other strains of MDV-1 reference sequences for comparison. Three strains of long repeats length of approximately 12 kb, predicted open reading frame (Open reading frame, ORF) were 43, 40, 43; short repeat region of approximately 12kb, predicted ORF were 27 a, 25, 26. Three strains present their unique multiple ORF amino acid mutation in common, is the MDV-1 pandemic strain-specific genetic characteristics. Phylogenetic tree analysis showed that three strains in the genomic sequence repeats with high homology in evolution is an independent branch. In this study, for the first time three popular domestic MDV-1 strain genome sequence repeats were systematically measured and analyzed in order to MDV-1 prevalence and variation to provide research materials.