Beak and feather disease virus and porcine circovirus genomes: intermediates between the geminiviruses and plant circoviruses

Abstract

Circoviruses are a diverse group of animal and plant pathogens with undefined relationships to one another but for their non-geminate, non-enveloped capsids and circular, single-stranded DNA genomes. The sequences of the beak and feather disease virus and porcine circovirus genomic DNAs are presented and analyzed in the context of the other members of the family. Sequence comparisons, inferred phylogenies, and geographic occurrence suggest that the ambisense circoviruses, particularly the beak and feather disease virus, represent an evolutionary link between the geminiviruses and the plant circoviruses. We propose that the family members be reclassified into three groups: The family Circoviridae consists of the animal pathogens (beak and feather disease virus and porcine circovirus) that possess ambisense genomes with striking similarities to the geminiviruses. The BBTV-like viruses include the plant pathogens (coconut foliar decay virus, banana bunchy top virus, subterranean clover stunt virus) with a geminivirus-like stem-loop element in their DNAs, and single to multiple component genomes. The chicken anemia virus is an unassigned virus possessing unique characteristics bearing little similarity to the other ssDNA viruses.

Pigeon circovirus infection: Pathological observations and suggested pathogenesis

“…CAV, PBFD virus and porcine circovirus. Yet recent DNA cloning and sequencing studies have described striking similarities between porcine circovirus and Pigeon circovirus infection 155 PBFD virus genomes (Niagro et al, 1998), whereas no such homologies were found when these two viruses were compared with CAV (Bassami et al, 1998). The pigeon circovirus has been described as antigenically distinct from PBFD virus, although possible homologous DNA sequences, as demonstrated by DNA in situ hybridization, have been found between both viruses (Woods et al, 1994).…”

“…Circoviruses are tiny non-enveloped icosahedral viruses (15-24 nm in diameter) with a single-stranded circular DNA of 1.76 kb to 2.31 kb (Bassami et al, 1998;Niagro et al, 1998). Like most other members of the newly proposed Circoviridae family, PiCV is characterized by typical basophilic globular inclusions in light microscopy (Woods et al, 1993;Shivaprasad et al, 1994;Woods et al, 1994).…”

Analyses of TT virus full-length genomic sequences.

“…While several small stem-loop structures were conserved in the full-length genomes, there was no apparent conserved nonanucleotide sequence or surrounding repetitive sequences. However, similar to circoviruses capsid proteins, the amino terminus of ORF1 possesses a high number of arginine residues (Niagro et al, 1998 ;Mushahwar et al, 1999). Thus, the TT virus ORF1 product may have DNA-binding activity and function in packaging of the viral genome.…”

Duplex Shuttle PCR for Differential Diagnosis of Budgerigar Fledgling Disease and Psittacine Beak and Feather Disease

“…The causative agent, PBFD virus (PBFDV), is a nonenveloped icosahedral DNA virus with a diameter of 14-17 nm (2,18,32). It carries single-stranded circular DNA with a complete genome size of about 2 kb (2,18,32).…”