title: Using PCR for early diagnosis  of bovine leukemia virus infection in some native cattle.
abstract: Bovine  leukemia virus (BLV), the causative agent of enzootic bovine leukosis, is an  exogenous, B lymphotropic retrovirus belonging to the Retroviridae family that  induces persistent lymphocytosis in cattle and sheep. PCR has proven to be  particularly suitable for investigating herds of cattle with a very low  incidence of BLV infection and for clarifying doubtful serological results  obtained by immunodiffusion or ELISA. The native Iranian and Russian cattle  have a series of valuable traits that discriminate them as unique breeds that  are well able to compete with western analogues. However, their gene pools have  not been analyzed with molecular markers, including detection of BLV by PCR.  Two pairs of primers were used: gag1 and gag2, and pol1 and pol2, which  encompass 347- and 599-bp fragments of the BLV gene, respectively. Sixty-five  Iranian Sistani, 120 Yaroslavl, 50 Mongolian, and 35 Black Pied cows were  investigated. Among these 270 animals, we obtained 42 positive and 15 doubtful  results in the first PCR. The second PCR was very effective in increasing BLV  test reliability data to support detection of BLV.
authors: Department of Animal Sciences, Shahid Bahonar University, Kerman, Iran. mmohammadabadi@yahoo.ca
authors: M R
authors: MR
authors: Mohammadabadi
authors: M
authors: M
authors: Soflaei
authors: H
authors: H
authors: Mostafavi
authors: M
authors: M
authors: Honarmand
mesh_terms: D000818:Animals; D002417:Cattle / Q000097:blood / Q000821:virology*; D016583:Enzootic Bovine Leukosis / Q000097:blood / Q000175:diagnosis* / Q000235:genetics*; D015750:Genes, gag / Q000235:genetics; D015751:Genes, pol / Q000235:genetics; D001909:Leukemia Virus, Bovine / Q000235:genetics*; D016133:Polymerase Chain Reaction / Q000379:methods*