Differential Adaption on Marc-145 Cell between High and Low Generations of Highly Pathogenic Porcine Reproductive and Respiratory Syndrome Virus
|School||China Institute of Veterinary Drug Control|
|Course||Preventive Veterinary Medicine|
|Keywords||Porcine reproductive and respiratory syndrome virus Of Macr-145 cells adaptability Suppression subtractive hybridization Differential gene|
Porcine reproductive and respiratory syndrome (Porcine Reproductive and Respiratory Syndrome, PRRS) caused by porcine reproductive and respiratory syndrome virus (Porcine Reproductive and Respiratory Syndrome Virus, PRRSV) capable of causing the pregnant sow abortion and piglets breathing disorders diseases . PRRSV host cell tropism, only a few cell lines for PRRSV infection and proliferation. Cell receptors and intracellular macromolecules, including multiple factors PRRSV infection of host cells. The generation process PRRSVGD strains vitro each generation times TCID50 values ??rise with the generation times increase. In vitro generation and generation of the 100 PRRSV GD strains infection of Marc-145 cells, and both produce the CPE time difference larger, 5 generations required 34 hours, and 100 generation is shortened to 24 hours. By sequencing PRRSV GD strains between 5 to the 100 generation genome sequence analysis, in vitro passage, the genome sequences 29 base mutations, these mutations lead to a 18 amino acid mutations occur. About 77.8% of the amino acid mutations occur before 50 generations, while 66.7% of the amino acid mutations occur in the open reading frame encoding non-structural proteins. Using UTRscan analyzed 5'UTR functional element, no change occurs. PRRSV GD strain changes in the structure of genes between different generations times may be one of the reasons that the cell adaptability differences lead to different generations virus on Marc-145 cells. Due to encoding non-structural proteins and the ORF encoding structural proteins have amino acid residue mutations occurred, it is difficult to explain the type of amino acid mutations result in a virus-host cell adaptive changes. PRRSV for differences in cell genome transcriptional regulation may be one of the important reasons that cause the host cell adaptation differences. Constructed to reflect the differential cDNA library of different generations PRRSV GD strains of Marc-145 cells mRNA transcript expression of different genes infection by using suppression subtractive hybridization. The three time points of the selection of infection after 12 hours, 24 hours and 36 hours was observed at different times in the case of the differentially expressed genes. By differences in gene sequencing and the BLAST comes from Marc-145 cells 11 kinds of primates are highly homologous genes and unknown genes for transcription differentially expressed genes. Six of the 11 known genes, ribosomal protein genes. However, due to the small study of these genes, the functions of these genes is not yet clear. The experiment results of PRRSV GD strain infection level of generation of Marc-145 cells gene transcription is indeed different, and this difference may be related to adaptive differences with the host cell.