SEQUENCE DETERMINATION OF THE EXTREME 5' END OF EQUINE ARTERITIS VIRUS LEADER REGION

The extreme 5' end of the leader sequence of four equine arteritis vir us (EAV) strains was obtained by using rapid amplification of cDNA end method (5' RACE), and sequenced. Seventeen more nucleotides were adde d upstream of the 5' end of the EAV published genomic sequence. A comm on feature among the analyzed EAV isolates was the presence of an AUG start codon within the added sequence and the appearance of an intrale ader open reading frame (ORF) of 111 nucleotides which was predicted t o encode a peptide of 37 amino acids. The role of this putative intral eader ORF has yet to be determined.