title: A nested set of six or seven subgenomic mRNAs is formed in cells infected with different isolates of porcine reproductive and respiratory syndrome virus.
abstract: The subgenomic mRNAs (sg mRNA) of porcine reproductive and respiratory syndrome virus (PRRSV) were characterized. The number of sg mRNAs, which form a 3'-coterminal nested set in PRRSV-infected cells, varied from six to seven among PRRSV isolates with differing virulence. The additional species of sg mRNA in some isolates of PRRSV was designated as sg mRNA 3-1. The leader-mRNA junction sequences of sg mRNAs 3, 3-1 and 4 were found to contain a similar six nucleotide sequence motif, U(G)UA(G/C)ACC. By comparing the 5'-terminal sequence of sg mRNA 3-1 with the genomic sequence of two isolates, ISU79 and ISU1894, it was found that a point mutation, from U in isolate ISU1894 to C in isolate ISU79, led to the acquisition of a new leader-mRNA junction sequence (UUGACC) in isolate ISU79, and therefore an additional species of sg mRNA 3-1. A small ORF (3-1) was identified at the 5' end of sg mRNA 3-1.
authors.affiliation: Department of Microbiology, Immunology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, Ames 50011, USA.
authors.forename: X J
authors.initials: XJ
authors.lastname: Meng
authors.forename: P S
authors.initials: PS
authors.lastname: Paul
authors.forename: I
authors.initials: I
authors.lastname: Morozov
authors.forename: P G
authors.initials: PG
authors.lastname: Halbur
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018018:Arterivirus / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D018174:Arterivirus Infections / Q000662:veterinary* / Q000821:virology; D001483:Base Sequence; D015152:Blotting, Northern; D002460:Cell Line; D003062:Codon; D017931:DNA Primers; D015342:DNA Probes; D018076:DNA, Complementary; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D012333:RNA, Messenger / Q000096:biosynthesis*; D017386:Sequence Homology, Amino Acid; D012689:Sequence Homology, Nucleic Acid; D013552:Swine; D013553:Swine Diseases; D013728:Terminator Regions, Genetic
chemical_list: D003062:Codon; D017931:DNA Primers; D015342:DNA Probes; D018076:DNA, Complementary; D012333:RNA, Messenger