Atadenoviruses

This is the summary of a lecture held at the Hungarian Academy of Sciences at the event commemorating the 75(th) anniversary of the late Professor BAR THA's birth. One of the many successful research fields of his was the isol ation, characterisation and classification of animal adenoviruses. In the m id 60s, several bovine adenovirus (BAdV) strains were isolated by BARTHA an d his co-workers in Hungary that seemed to be very different from the (at t hat time three) known BAdVs. The special properties included the restricted (to primary bovine testicle cell cultures) replication, different nuclear inclusion body morphology, elevated heat resistance, and above all the lack of crossreactivity with other mammalian adenoviruses in complement-fixatio n test. BARTHA proposed the taxonomic separation of these viruses (serotype s 4, 5, 6, 7, and 8) into a new genus, but due to lack of more convincing p roofs, only a separate subgroup, the so-called subgroup 2 was created at th at time. Continuing the research work of ADORJAN BARTHA, we have compiled m olecular biological data supporting the separation of these viruses on the genus level. DNA sequencing, detailed genetic mapping and phylogenetic anal yses (Figure) suggest, that beside the members of the Aviadenovirus and Mas tadenovirus genera a group of third type adenoviruses exist comprising subg roup 2 BAdVs,,ovine adenovirus" isolate 287, and the egg drop syndrome (EDS ) virus (earlier considered as a deviant member of aviadenoviruses). A prop osal has been made to the ICTV for establishing a new adenovirus genus. The most striking distinguishing features of the candidate members of the prop osed genus include a relatively compressed, AT-rich genome, the lack of ide ntifiable early regions EIA and E3, the lack of the genes of structural pro teins V and IX, and the presence of a new structural protein (p24/32K) code d on the 1 strand. Because of the high AT content (57-66%), the name Ataden ovirus has been proposed for this genus.