identification of a specific pseudo attp site for phage phic3 integrase in the genome of chinese hamster in cho-k1 cell line

background: phic31 integrase is a dna site-specific recombinase integrates dna into the chromosomes between the two sites of attb and attp. several pseudo attps have been identified in mammalian genomes with critical features for long-term expression of transgene. in this manuscript, we report a novel intrinsic pseudo attp site named chol1 in the chinese hamster genome implementing an inverse polymerase chain reaction (ipcr). objectives:identification of pseudo attp site(s) of tenecteplase cdna integration in the genome of stable transformed cho cell line. materials and methods: first, genome was extracted from a stable transformed cho cell line expressing tenecteplase. by creating of minicircle dna in the last step, sequenc­ing was performed. results: we obtained one band. blast analysis of the respective sequence of inverse pcr band identified a pseudo attp site. conclusions: data demonstrated that the phic31 integrase provides a suitable insertion site in the genome to express the gene of interest.