title: [Genetic variation and pathogenicity analysis of highly pathogenic porcine reproductive and respiratory syndrome virus strain TJ in the course of attenuation].
abstract: To develop an attenuated vaccine against the highly pathogenic porcine reproductive and respiratory syndrome (HP-PRRS) virus, the HP-PRRS virus strain TJ was attenuated by serial passages and plaque cloned every 5 to 10 passages in Marc-145 cells. Genetic variation and pathogenicity of HP-PRRSV strain TJ in the course of attenuation were analyzed. The results showed that the strain TJ sustained various sequence changes during the course of attenuation. Fifty-eight amino acids changes and a new continuous 120 amino acids deletion after the discontinuous 30 amino acids deletion (sites 481 and 533-561) occurred in strain TJ passages 140, and the position of 120 amino acids deletion was between 628 to 747 according to VR-2332. Animal test showed that the pathogenicity of strain TJ passages 20 was attenuated obviously, so we presume that genetic variation in nonstructural protein nsp2-nsp5, nsp7 and structural protein GP5 during the attenuation provides the molecular bases for the observed attenuated phenotype.
authors.affiliation: Division of Zoonosis, Institute of Special Economic Animal and Plant Sciences, Chinese Academy of Agricultural Science, Jilin 132109, China. lengxue_79@163.com
authors.lastname: Leng-Xue
authors.forename: Zhen-Guang
authors.initials: ZG
authors.lastname: Li
authors.forename: Xi-Yu
authors.initials: XY
authors.lastname: Li
authors.forename: Feng-Xue
authors.initials: FX
authors.lastname: Wang
authors.forename: Xiu-Hua
authors.initials: XH
authors.lastname: Zhang
authors.lastname: Wu-Hua
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D014644:Genetic Variation; D008969:Molecular Sequence Data; D019318:Porcine Reproductive and Respiratory Syndrome / Q000821:virology*; D019316:Porcine respiratory and reproductive syndrome virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity*; D017384:Sequence Deletion; D012692:Serial Passage; D013552:Swine; D014613:Vaccines, Attenuated / Q000235:genetics / Q000302:isolation & purification; D014774:Virulence
chemical_list: D014613:Vaccines, Attenuated