| Abstract：Abstract: In order to elucidate the potential relationship between persistent infection of foot-and-mouth disease virus and FMDV genetic variation, to further investigate the variance of VP1 and 3ABC gene of the persistent infection isolates. With a dose of 104ID50/ml of O/Akesu/58 FMDV strain, five Chinese yellow cattle were inoculated on their tongue. Following clinical or sub-clinical signs, they became asymptomatic FMDV persistently infection state. Monthly, with probang to scrape esophageal-pharyngeal（O/P）fluids from experimental cattle, then inoculated into baby hamster kidney cell line(BHK-21). There are 12 persistent FMDV strains isolates. VP1 and 3ABC gene were amplified by RT-PCR. Sequence analyses revealed VP1 gene had 16 identical mutations in nucleotide sequences compared with their parental strain, only two point mutation led to amino acid change(I56→T,A210→E),and there were transversion mutations of 4 nucleotide and 3 amino acid among the iaolates. In 3ABC gene there were only 13 nucleotide transversion mutations and 5 deduced amino acids mutations. The results indicated FMDV persistent infection is no direct and close related to genetic variation of VP1 and 3ABC gene, maybe the gene related to persistent infection is gone beyond VP1 and 3ABC regions. |
