the polymerase chain reaction (pcr) was used to amplify a 578 bp fragment of the poxvirus 4b core protein. avipoxvirus (apv) specific dna was detected in all 10 different isolates (each of which had been isolated from an epidemic) isolated from chicken; canary and mynah were collected from tehran province. sequencing was performed for 2 isolates as representative and the nucleotide sequence sho...