The purpose of this project is the study of genome structure and function of the Aleutian mink disease parvovirus (ADV). In the past year, we confirmed the sequence of the ADV-G strain of ADV and derived molecular clones containing the 5'-palindrome (right hand terminus). Detailed computer analysis of the ADV-G sequence has revealed that the 3'-terminal palindrome could assume/a Y-shaped configuration, similar to that of the other parvoviruses, but was less stable thermodynamically. Furthermore, the overall homology to other parvoviruses was less than 50 percent, but short conserved amino acid regions were noted in both the left and right major open reading frames (ORFs). Two allegedly conserved regions in the right ORF were not found in ADV. ADV-G was 97.5% related to the virulent ADV-Utah 1 in a comparison encompassing 76% of the genomes, but we observed a short hypervariable region in the right ORF in which 8 of 11 amino acid residues varied. This short sequence may correspond to regions in other parvoviruses that govern host-range and virulence, and, thus, may be responsible for the pathogenicity characteristics of different ADV strains. A molecular clone of ADV-G that contains the full sequence, including both termini, has been constructed and is now being tested for infectivity. The transcription program of ADV-G has been analyzed in detail using Northern blotting, cDNA cloning, DNA sequencing, and primer extension. ADV had 5 polyadenylated RNA transcripts of 4.3 (R1), 2.8 (R2), 2.8 (R3), 1.1 (RX), and 0.85 (R2') kb. Each mRNA had ORFs suggestive of bona fide protein coding sequences, initiating from promoters at 3 map units (R1, R2, R2', and RX) or at 36 map units (R3) and terminating at polyadenylation sites at map unit 53 (R2' and RX) or map unit 92. A transcript with characteristics of RX has not been previously described for the parvoviruses. R3 almost certainly coded for the capsid proteins (p85 and p75); R1, for the largest nonstructural proteins (p71); and the others, for 1 or more additional nonstructural proteins.
