Molecular characterisation of novel circoviruses from finch and gull

Daniel Todd (1)

1 AFBI

The purpose of this study was to molecularly characterise circoviruses that infect finch and gull. Circovirus-specific DNAs were isolated using PCR methods from bursa of Fabricius tissues from a Gouldian finch (Chloebia gouldiae) and a herring gull (Larus argentatus ) that were known to be circovirus-infected. Nucleotide sequence determination and analysis of cloned genomic DNAs showed that these circoviruses represented novel members of the genus Circovirus of the family Circoviridae, and have been tentatively named Finch circovirus (FiCV) and Gull Circovirus (GuCV). Both new circoviruses shared genome organisational features with previously characterised circoviruses, such that both contained 2 major, inversely-arranged open reading frames (ORFs) encoding the putative replication associated and capsid proteins, and both contained a potential stem-loop and nonanucleotide motif. Phylogenetic analyses based on genome nucleotide sequences and involving the 7 additional genus members indicated that FiCV and GuCV were more closely related to canary circovirus (CaCV), beak and feather disease virus (BFDV) and pigeon circovirus (PiCV), and that FiCV and CaCV were the most closely related avian circoviruses. Pairwise comparisons showed that the capsid proteins of FiCV and GuCV shared highest amino acid identity values with those of CaCV (62.0%) and PiCV (40.6%) respectively. The 5`intergenic region of GuCV was longer (207 nucleotides) and contained more direct and inverse repeated sequences than those of other circoviruses, while the 3`intergenic region of FiCV was notable in being longer (307 nucleotides) than its counterparts in other circoviruses and in containing 2 long repeats of 77 nucleotides.

Mots clés: Life Sciences

Daniel Todd. Molecular characterisation of novel circoviruses from finch and gull. Avian Pathology, 2007, 36 (01), pp.75-81. ⟨10.1080/03079450601113654⟩. ⟨hal-00540066⟩