SEQUENCE ANALYSES OF THE P24 GENE OF BORNA-DISEASE VIRUS IN NATURALLYINFECTED HORSE, DONKEY AND SHEEP

By reverse transcriptase/PCR amplification and subsequent sequence det ermination of the p24 gene, the relatedness of Borna disease virus (BD V) in various naturally infected animal species was determined. These results are indicative of a common ancestral virus pool and a remarkab ly low species barrier of BDV. Comparison of 11 sequences to that of t issue culture adapted virus revealed that the homology among all isola tes was at least 96.2% at the nucleotide level, and 97% at the amino a cid level. Viral sequences from sheep, donkey and horse were found to be not more distantly related to each other than sequences from differ ent infected horses. Tissue-specific virus variants were detected in o ne horse: the sequences established from infected cerebrum and kidney showed 10 mutations, whereas sequences obtained from parotid gland con tained 20 mutations in comparison to the nucleotide sequence of MDCK c ell adapted BDV.