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Zhang X.,South China Agricultural University | Liu Y.,South China Agricultural University | Ji J.,South China Agricultural University | Chen F.,South China Agricultural University | And 6 more authors.
BioMed Research International | Year: 2014

The chicken anemia virus (CAV), is a known member of the genus Gyrovirus and was first isolated from chickens in Japan in 1979. Some reports have also demonstrated that CAV can be identified in human stool specimens. In this study, a variant of CAV was detected using PCR with CAV-based primers in fecal samples of stray cats. The genome of CAV variant was sequenced and the results suggest that it could be a recombinant viral strain from parental CAV strains JQ690762 and AF311900. Recombination is an important evolutionary mechanism that contributes to genetic diversification. These findings indicate that CAV variant might have originated from CAV-infected chickens. The epidemiology and pathogenesis of this novel virus remains to be elucidated. This study underscores the importance of CAV surveillance and it presents the first evidence suggesting the possibility of CAV homologous recombination in cat. © 2014 Xinheng Zhang et al.

Liao C.T.,South China Agricultural University | Liao C.T.,Key Laboratory of Chicken Genetics | Chen S.Y.,South China Agricultural University | Chen W.G.,South China Agricultural University | And 10 more authors.
Poultry Science | Year: 2014

Avian leukosis is an immunosuppressive neoplastic disease caused by avian leukosis viruses (ALV), which causes tremendous economic losses in the worldwide poultry industry. The susceptibility or resistance of chicken cells to subgroup A ALV and subgroup B, D, and E ALV are determined by the receptor genes tumor virus locus A (tva) and tumor virus locus B (tvb), respectively. Four genetic resistant loci (tvar1, tvar2, tvar3, and tvar4) in tva receptor gene and a genetic resistant locus tvbr in the tvb receptor gene have been identified in inbred lines of White Leghorn. To evaluate the genetic resistance to subgroup A, B, D, and E ALV, genetic variations within resistant loci in tva and tvb genes were screened in Chinese local chicken breeds and commercial broiler lines. Here, the heterozygote tvas1/r1 and the resistant genotype tvar2/r2, tvar3/r3, and tvar4/r4 were detected in Chinese chickens by direct sequencing. The heterozygote tvas1/r1 was detected in Huiyang Bearded chicken (HYBC), Rizhaoma chicken, and commercial broiler line 13 to 15 (CB13 to CB15), with the frequencies at 0.08, 0.18, 0.17, 0.25, and 0.15, respectively. The resistant genotype tvar2/r2 was detected in Jiningbairi chicken (JNBRC), HYBC, and CB15, with the frequencies at 0.03, 0.08, and 0.06, respectively, whereas tvar3/r3 and tvar4/r4 were detected in 19 and 17 of the 25 Chinese chickens tested, with the average frequencies at 0.13 and 0.20, respectively. Furthermore, the resistant genotype tvbr/r was detected in JNBRC, CB07, CB12, CB14, and CB15 by pyrosequencing assay, with the frequencies at 0.03, 0.03, 0.11, 0.09, and 0.15, respectively. These results demonstrated that the potential for genetic improvement of resistance to subgroup A, B, D, and E ALV were great both in Chinese local chickens and commercial broilers. This study provides valuable insight into the selective breeding for chickens genetically resistant to ALV. © 2014 Poultry Science Association Inc.

Zhang X.,South China Agricultural University | Liu Y.,South China Agricultural University | Wu B.,South China Agricultural University | Sun B.,South China Agricultural University | And 5 more authors.
Scientific Reports | Year: 2013

Chicken anemia virus (CAV) is an important pathogen that causes severe immunosuppression in young chickens. We have characterized 13 CAVs isolated from different commercial farms in southern China between 2011 and 2012. We discovered 92 variable residues compared to 37 other CAV complete genome sequences from other parts of the world listed in GenBank; these residues have not been previously observed. All of the Chinese CAV genomes that were characterized in this study had a glutamine at position 394, a hallmark of highly pathogenic CAVs. We also discovered that intra-group genetic recombination plays a role in generating genetic diversity in natural populations of CAV. The GD-J-12 isolate was a possible recombinant between GD-C-12 and GD-M-12 in the genomic region that encompassed both the coding and non-coding regions.

Feng K.,South China Agricultural University | Feng K.,Key Laboratory of Chicken Genetics | Xue Y.,Guangdong Wens Food Co. | Wang F.,Guangdong Wens Food Co. | And 5 more authors.
Virus Genes | Year: 2014

Sixty-two strains of avian infectious bronchitis virus (IBV) were isolated from diseased chickens at different farms in southern China during 2011–2012, and 66.1 % of the isolated strains were associated with typical nephritis. Analysis of the S1 gene sequences amplified from the 62 isolated strains together with 40 reference strains published in Genbank showed nucleotide homologies ranging from 63.5 to 99.9 % and amino acid homologies ranging from 57.9 to 100 %. Phylogenetic analysis revealed that all Chinese IBV strains were clustered into six distinct genetic groups (I–VI). Most of the isolated strains belonged to group I, and the isolation of group V strains was increased compared with an earlier period of surveillance. Current vaccine strains used in China (H120, H52, W93, and Ma5) formed the group Mass which is evolutionarily distant from Chinese isolates. Alignment of S1 amino acid sequences revealed polymorphic and diverse substitutions, insertions, and deletions, and the S1 protein of major pandemic strains contained 540 amino acids with a cleavage site sequence of HRRRR or RRF(L/S)RR. Further analysis showed that recombination events formed a new subgroup. Taken together, these findings suggest that various IBV variants were co-circulating and undergoing genetic evolution in southern China during the observation period. Therefore, long-term continuing surveillance is significantly important for prevention and control of IBV infection. © 2014, Springer Science+Business Media New York.

Li X.-G.,South China Agricultural University | Li X.-G.,Guangdong Provincial Key Laboratory of Agro Animal Genomics and Molecular Breeding | Li X.-G.,Key Laboratory of Chicken Genetics | Chen X.-L.,South China Agricultural University | And 5 more authors.
Comparative Biochemistry and Physiology - A Molecular and Integrative Physiology | Year: 2013

This study was conducted to evaluate the embryonic development of broilers with different growth rates and correlate the differences between the amino acid transporter and peptide transporter gene expression patterns to the growth of the small intestine. The results showed that the body and yolk weights of the White Plymouth Rock (WPR) embryos were higher than those of the WENS Yellow Feather Chicken (WYFC) embryos although the relative embryonic body weights were inversely correlated. We studied nine organs and classified them into four clusters according to their changes in relative weight during the hatching process. The levels of gene expression of SLC7A9, SLC1A1 and SLC15A1 in the small intestine increased during embryo development and were affected by breed. Breed-specific differences in embryonic development were observed for SLC7A9, SLC1A1 and SLC15A1 gene expression. When represented as a function of SLC7A9, SLC1A1 or SLC15A1 gene expression, strong correlations were observed for the weight of small intestine. We conclude that WPR embryos have a higher absolute growth rate but a lower relative growth rate in comparison with WYFC embryos. Moreover, the expression levels of the SLC7A9, SLC1A1 or SLC15A1 genes can be used as indicators for the growth of the small intestine. © 2012.

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