Complete genome sequence of avian paramyxovirus type 7 (strain Tennessee) and comparison with other paramyxoviruses

The complete genome sequence of avian paramyxovirus serotype 7 (APMV-7) prototype strain dove/Tennessee/4/75 was determined. The genome size is 15,480 nucleotides (nt) long and follows the rule of six. The genome contains six non-overlapping genes in the order of 3'-N-P/V/W-M-F-HN-L-5'. The T-leader and 5'-trailer sequences of the genome are 55 and 127 nt long, respectively. The first 12 nt of the leader and trailer sequences are complementary to each other. The viral genes are flanked by highly conserved gene-start (GS) and gene-end (GE) transcription signals, and in addition the T-leader sequence contains a sequence ((35)AAUUAUUUUUU(45)) that is identical to the GE signal present at two of the genes. The genes are separated by intergenic sequences (IGS) ranging between 11 and 70 nt. The phosphoprotein (P) gene contains a conserved RNA editing site (3'-UUUUUCCC-5') presumed to be involved in the production of V and W proteins. The viral fusion (F) protein has a single basic amino acid at the putative cleavage site ((TLPSS)-T-101 (R) under bar down arrow F-107); however, the virus did not require exogenous protease for in vitro replication. The virus grew in only a few established cell lines, indicating a restricted host range. Sequence alignment and phylogenetic analysis of the predicted amino acid sequence of APMV-7 proteins with the cognate proteins of the viruses of all five genera of the family Paramyxoviridue showed that APMV-7 is more closely related to APMV-2, -6, -8 than to APMV-1, -3, -4 and -9. The mean death time in embryonated chicken eggs was found to be more than 144 h, indicating APMV-7 to be avirulent for chickens. Crown Copyright (C) 2009 Published by Elsevier B.V. All rights reserved.