Whole-genome sequences of Odocoileus hemionus deer adenovirus isolates from deer, moose and elk are highly conserved and support a new species in the genus Atadenovirus

Abstract

We present the first complete genome sequence of Odocoileus hemionus deer adenovirus 1 (OdAdV-1). This virus can cause sporadic haemorrhagic disease in cervids, although epizootics with high mortality have occurred in California. OdAdV-1 has been placed in the genus Atadenovirus, based on partial hexon, pVIII and fibre genes. Ten field isolates recovered from naturally infected mule deer (Odocoileus hemionus), white-tailed deer (Odocoileus virginiana) and moose (Alces alces) from Wyoming, black-tailed deer (Odocoileus hemionus columbianus) from California, and Rocky Mountain elk (Cervus elaphus nelsoni) from Colorado and Washington state were sequenced. The genome lengths ranged from 30 620 to 30 699 bp, contained the predicted proteins and gene organization typical of members of genus Atadenovirus, and had a high percentage of A/T nucleotides (66.7 %). Phylogenic analysis found that the closest ancestry was with ruminant atadenoviruses, while a divergence of the hexon, polymerase and penton base proteins of more than 15 % supports classification as a new species. Genetic global comparison between the 10 isolates found an overall 99 % identity, but greater divergence was found between those recovered from moose and elk as compared to deer, and a single variable region contained most of these differences. Our findings demonstrate that OdAdV-1 is highly conserved between 10 isolates recovered from multiple related cervid species, but genotypic differences, largely localized to a variable region, define two strains. We propose that the virus type name be changed to cervid adenovirus 1, with the species name Cervid atadenovirus A. Sequence data were used to develop molecular assays for improved detection and genotyping.

Adenoviruses across the animal kingdom: a walk in the zoo

“…The diversity of these AdV types implies that the presumed ancient host switch from the original reptilian host to a ruminant animal might have taken place before the divergence of the recent ruminant lineages. The full genomic sequences, for example, from ovine AdV‐7, bovine AdV‐4 to ‐8, or deer AdV‐1 (from Odocoileus ) revealed characteristic differences, such as the duplication or even multiplication of the RH genes, compared to the reptilian AdV genomes.…”

Molecular Characterisation of a Novel and Highly Divergent Passerine Adenovirus 1

“…Like most atadenoviruses, the PaAdV-1 genome contained a central conserved coding region bounded by two identical inverted terminal repeat (ITR) regions. The length of the ITR varies considerably in other atadenoviruses and ranges from 40 to 194 bp long [ 9 , 10 ]. The ITR of PaAdV-1 encompassed 193 bp each with the coordinates of 1–193 sense orientation and 39,450–39,642 antisense orientation.…”

“…PaAdV-1 was more similar to PsAdV-3 than any other atadenoviruses, by virtue of genome structure, complete genome sequence similarity (>55%), and G+C content ( Table 2 ). The length of the ITRs of PaAdV-1 (193-bp) is significantly different from the ITRs of avian and ruminants atadenoviruses [ 9 , 11 , 47 ]; however, it seems to be similar in length to reptilian atadenoviruses [ 10 ]. Generally, the length of ITRs varies significantly throughout the family of Adenoviridae, being over 100 bp in the case of Mastadenovirus, Ichtadenovirus , and most of Aviadenovirus , while shorter than 60 bp in Siadenovirus and most of the non-reptilian atadenoviruses [ 9 , 10 , 48 ].…”

“…A feature of adenoviruses is their ability to acquire genes from their hosts, bacteria, fungi, and other viruses. The Atadenoviruses appear to be particularly adept at this and all atadenoviruses sequenced to date contain five or more genes acquired from other organisms or whose origin is not known [ 5 , 8 , 9 , 10 ]. These genes are diverse in their function and appear to be lost as often as they are acquired as the atadenoviruses evolve.…”

“…Atadenoviruses have been detected in a diverse range of hosts, including birds [ 4 , 11 , 12 , 13 , 14 , 15 , 16 , 17 , 18 ], reptiles (order Squamata; lizards, snakes, and worm lizards), ruminants [ 8 , 9 , 15 , 19 ], marsupials [ 20 , 21 ], and a common tortoise [ 22 ]. Using a partial DNA polymerase gene sequence, recent studies also report the presence of a large number of novel atadenoviruses circulating in wild passerine species of birds in Australia and Europe and passerine species kept in aviculture collections [ 4 , 17 , 18 ].…”