Determination of avian endogenous provirus - cellular junction sequences using inverse polymerase chain reactions

The inverse polymerase chain reaction (invPCR), based on using sets of oligonucleotide primers oriented in the reverse direction of the usual PCR, was used to amplify cell sequences that flank chicken endogenous virus (ev) genes. Inverse PCR products flanking the 5’ region of ev7 and ev12 were cloned and cell nucleotide sequences were determined. Subsequent PCRs were conducted using primers based on cell sequences flanking ev7, ev12, and the proviral long terminal repeat of ev1. In a survey of experimental and commercial lines and breeds, ev12 was found among three broiler lines. This approach facilitates the identification of ev genes in breeding stocks without conducting prior conventional progeny testing. Moreover, specific ev genes may be detected in individuals harboring a variety of other ev genes.