THE COMPLETE NUCLEOTIDE-SEQUENCE OF THE EGG DROP SYNDROME VIRUS - AN INTERMEDIATE BETWEEN MASTADENOVIRUSES AND AVIADENOVIRUSES

The complete nucleotide sequence of an avian adenovirus, the egg drop syndrome (EDS) virus, was determined. The total genome length is 33,21 3 nucleotides, resulting in a molecular weight of 21.9 x 10(6). The GC content is only 42.5%. Between map units 3.5 and 76.9, the distributi on of open reading frames with homology to known genes is similar to t hat reported for other mammalian and avian adenoviruses. However, no h omologies to adenovirus genes such as E1A, pIX, pV, and E3 could be fo und. Outside this region, several open reading frames were identified without any obvious homology to known adenovirus proteins. In the regi on organized similarily as other adenoviral genomes, most homologies w ere found to an ovine adenovirus (OAV strain 287). The highest level o f amino acid identity was found for the hexon proteins of EDS and OAV. The virus-associated RNA(VA RNA) was identified thanks to the homolog y with the VA RNA of fowl adenovirus serotype 1 (FAV1). similarities w ith FAVI were also found in the fiber protein. Our results demonstrate that the avian EDS virus represents an intermediate between mammalian and avian adenoviruses. The nucleotide sequence and genomic organizat ion of the EDS virus reflect the heterogeneity of the aviadenovirus ge nus and the Adenoviridae family. (C) 1997 Academic Press.