Oligonucleotide fingerprint analysis of a wild strain & its attenuated variant of Japanese encephalitis virus

A strain of Japanese encephalitis (JE) virus was passaged serially through primary chick kidney cell cultures (45 times) and primary baby hamster kidney cell cultures (21 times). The resultant virus lost its lethal effect to 3 wk old mice by the ic route and 10 day old mice by the ip route. The oligonucleotide fingerprint analysis of the parent and the passaged strains showed 64 spots in common; 17 spots were present in the parent strain which were absent in the passaged virus, while the latter had acquired 9 spots which were not present in the parent virus.