Zhou P.,South China Agricultural University |
Zhou P.,Shanghai Veterinary Research Institute |
Nie H.,Huazhong Agricultural University |
Zhang L.-X.,Henan Agricultural University |
And 5 more authors.
Journal of Parasitology | Year: 2010
Toxoplasma gondii genetic diversity varies in different geographical regions. In South America, T. gondii isolates are highly diverse, whereas in North America and Europe, the parasite is highly clonal, with 3 distinct lineage types (I, II, III). However, little is known of the T. gondii genotypes in the People's Republic of China. Because pork is considered the principal meat source for T. gondii infection in China, we conducted a survey to determine the prevalence and genetic diversity of this parasite in pigs from central China. In total, 434 DNA samples were extracted from the hilar lymph nodes of sick pigs in Hubei and Henan provinces in central China, and 34 were T. gondii B1 gene-positive. These T. gondii-positive DNA samples were typed at 10 genetic markers, including 9 nuclear loci, i.e., SAG1, SAG2, SAG3, BTUB, GRA6, L358, PK1, c22-8, c29-2, and an apicoplast locus Apico. Of these, 16 isolates could be genotyped with complete data for all loci. Two genotypes were present; one was the clonal type I lineage and the other was previously identified as a widespread lineage from many hosts in China. These results indicate that these 2 genotypes may be the major lineages in China. This is the first report of genetic typing of T. gondii isolates from pigs in central China. The results have implications for the prevention and control of T. gondii infections in humans and other animals. © 2010 American Society of Parasitologists. Source
Long J.,Biological Mimetics, Inc. |
Long J.,Shanghai Veterinary Research Institute |
Bushnell R.V.,Biological Mimetics, Inc. |
Tobin J.K.,Biological Mimetics, Inc. |
And 6 more authors.
PLoS ONE | Year: 2011
Studies of influenza virus evolution under controlled experimental conditions can provide a better understanding of the consequences of evolutionary processes with and without immunological pressure. Characterization of evolved strains assists in the development of predictive algorithms for both the selection of subtypes represented in the seasonal influenza vaccine and the design of novel immune refocused vaccines. To obtain data on the evolution of influenza in a controlled setting, naïve and immunized Guinea pigs were infected with influenza A/Wyoming/2003 (H3N2). Virus progeny from nasal wash samples were assessed for variation in the dominant and other epitopes by sequencing the hemagglutinin (HA) gene to quantify evolutionary changes. Viral RNA from the nasal washes from infection of naïve and immune animals contained 6% and 24.5% HA variant sequences, respectively. Analysis of mutations relative to antigenic epitopes indicated that adaptive immunity played a key role in virus evolution. HA mutations in immunized animals were associated with loss of glycosylation and changes in charge and hydrophobicity in and near residues within known epitopes. Four regions of HA-1 (75-85, 125-135, 165-170, 225-230) contained residues of highest variability. These sites are adjacent to or within known epitopes and appear to play an important role in antigenic variation. Recognition of the role of these sites during evolution will lead to a better understanding of the nature of evolution which help in the prediction of future strains for selection of seasonal vaccines and the design of novel vaccines intended to stimulated broadened cross-reactive protection to conserved sites outside of dominant epitopes. © 2011 Long et al. Source
Kuang L.,University of Kentucky |
Kou H.,University of Kentucky |
Xie Z.,University of Kentucky |
Zhou Y.,University of Kentucky |
And 5 more authors.
DNA Repair | Year: 2013
DNA damage tolerance consisting of template switching and translesion synthesis is a major cellular mechanism in response to unrepaired DNA lesions during replication. The Rev1 pathway constitutes the major mechanism of translesion synthesis and base damage-induced mutagenesis in model cell systems. Rev1 is a dCMP transferase, but additionally plays non-catalytic functions in translesion synthesis. Using the yeast model system, we attempted to gain further insights into the non-catalytic functions of Rev1. Rev1 stably interacts with Rad5 (a central component of the template switching pathway) via the C-terminal region of Rev1 and the N-terminal region of Rad5. Supporting functional significance of this interaction, both the Rev1 pathway and Rad5 are required for translesion synthesis and mutagenesis of 1,N6-ethenoadenine. Furthermore, disrupting the Rev1-Rad5 interaction by mutating Rev1 did not affect its dCMP transferase, but led to inactivation of the Rev1 non-catalytic function in translesion synthesis of UV-induced DNA damage. Deletion analysis revealed that the C-terminal 21-amino acid sequence of Rev1 is uniquely required for its interaction with Rad5 and is essential for its non-catalytic function. Deletion analysis additionally implicated a C-terminal region of Rev1 in its negative regulation. These results show that a non-catalytic function of Rev1 in translesion synthesis and mutagenesis is mediated by its interaction with Rad5. © 2012 Elsevier B.V. Source
Shanghai Veterinary Research Institute | Date: 2012-09-04
A PR8 recombinant influenza virus contains an HA and/or NA gene of H1, H3, H4, H5, H6, H7, H9 or H10 subtype influenza virus, and 6 internal genes (PB1, PB2, PA, NP, M and NS genes) of PR8 virus, in which the NS and/or NP gene have the following mutation sites: the NS2 protein encoded by the NS gene has an E67S point mutation, E74S point mutation, or E67S/E74S point mutation, and the NP protein encoded by the NP gene has a G132A point mutation.
Shanghai Veterinary Research Institute | Date: 2012-04-26
A canine influenza recombinant virus includes HA and NA genes of ZJCIV canine influenza virus as well as six internal genes PA, PB1, PB2, M, NP and NS of a PR8 virus. The nucleotide sequence of the HA gene is selected from the group consisting of: (1) a nucleotide sequence encoding an amino acid sequence of SEQ ID NO.1; (2) a nucleotide sequence encoding an amino acid sequence which has at least 98% sequence identity to the amino acid sequence of SEQ ID NO.1. The nucleotide sequence of the NA gene is selected from the group consisting of: (1) a nucleotide sequence encoding an amino acid sequence of SEQ ID NO.2; (2) a nucleotide sequence encoding an amino acid sequence which has at least 98% sequence identity to the amino acid sequence of SEQ ID NO.2.