title: A duplex real-time reverse transcription polymerase chain reaction for the detection and quantitation of avian leukosis virus subgroups A and B.
abstract: Avian leukosis is a disease that is spreading widely in the world causing large economic losses to the poultry industry. In this study, a duplex quantitative real-time reverse transcription polymerase chain reaction (qRT-PCR) assay was developed to detect and quantify avian leukosis virus subgroups A and B (ALVA/B). The assay was optimised to measure viral gp85 and chicken housekeeping (β-actin) genes. The result showed that the assay was specific for reference strains of ALVA/B subtype and no cross-reaction was detected with ALV subtypes E and J or with four other non-ALV viruses. The assay detected as few as 56 gp85 cDNA copies and was 100-fold more sensitive than a conventional RT-PCR. Seventy clinical blood samples were evaluated by both the qRT-PCR and the conventional RT-PCR assay, and the results show that 65 samples were positive by the qRT-PCR compared with 43 by the conventional RT-PCR. When this assay was used to quantify the viral load in ALV-inoculated embryos from three congenic chicken lines, the embryos from the B21 line showed the highest viral load, whereas the lowest load was found in the B5 line. This assay provides a powerful tool for quantitative detection of the ALVA/B and for the study of host genetic resistance to avian leukosis.
authors.affiliation: Laboratory Animal Center, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, No. 427 Maduan Street, Nangang District, Harbin 150001, China.
authors.forename: Gang
authors.initials: G
authors.lastname: Zhou
authors.forename: Wenbo
authors.initials: W
authors.lastname: Cai
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Liu
authors.forename: Chengming
authors.initials: C
authors.lastname: Niu
authors.forename: Caixia
authors.initials: C
authors.lastname: Gao
authors.forename: Changde
authors.initials: C
authors.lastname: Si
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.forename: Liandong
authors.initials: L
authors.lastname: Qu
authors.forename: Lingxia
authors.initials: L
authors.lastname: Han
mesh_terms: D000818:Animals; D001353:Avian Leukosis / Q000821:virology*; D001354:Avian Leukosis Virus / Q000145:classification* / Q000235:genetics*; D001769:Blood / Q000821:virology; D002642:Chick Embryo; D002645:Chickens; D005838:Genotype; D058889:Molecular Typing; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods* / Q000592:standards; D012680:Sensitivity and Specificity