Adenoviruses are non-enveloped icoashedral viruses that contain a double stranded DNA genome ranging from 26 to 45 kb. These viruses cause a wide range of diseases in humans and animals ranging from respiratory illness, cystitis, hepatitis, conjunctivitis, gastroenteritis and in rare cases neurological disease.
From our experience, adenoviruses are commonly isolated from Pteropid (flying fox) urine in primary cell culture. In some cases multiple variants have be isolated from the same location at the same time, while similar variants were isolated from urine of flying foxes hundreds or even thousands of kilometers apart (from Hervey Bay in Queensland to Geelong in Victoria).
To investigate the pteropid Adenoviruses more closely, their genomes were sequenced using next generation sequencing on the MiSeq Sequencer (Illumina) and were compared with related adenoviruses. Deep sequencing revealed that there were sometimes more than one variant isolated. The genome of 29 kb displayed a genome structure of members of the genus Mastadenovirus. A dUTPase was located at the carboxy terminal end, that was more related to eukaryotic dUTPases than to ones of the Mastadenovirus genera.
Unlike most Mastadenoviruses which are GC rich (commonly ranging from 43-63%), the genome of the pteropid adenoviruses had a lower GC content of 36%. Recently, Cortes-Hinojosa and co-workers (2015) reported the sequencing of California sea lion adenovirus which revealed a similar low GC content. This group have suggested that the AT bias might allow for “host-jumping” by avoiding the innate immunity of the new host.
However, in this case of the pteropid adenoviruses, the AT bias may reflect an adaption within its reservoir host to allow for it to be maintained.
Reference: Cortes-Hinojosa et al., Infect Genet Evol. (2015) 31: 270-6.