ABSTRACT
The genome NiV is 18,246 nucleotides in length, and is among the largest genomes found among the Paramyxovirinae that have an average genome size of approximately 15,500 nucleotides. The increased size is mostly due to the large size of the open reading frame for the P gene and the large 3′ nontranslated regions present in several genes [3,5]. The “rule of six” states that the total length of the genomic RNA of viruses within the subfamily Paramyxovirinae must be evenly divisible by six in order to replicate [6] and the size of the genome NiV is evenly divisible by six. Analysis of the complete genomic sequences of the NiV strains associated with the outbreaks in Malaysia in 1999 (NiV-M) and Bangladesh in 2004 (NiV-B) showed that the genome of NiV-B is six nucleotides longer than NiV-M, the prototype strain of NiV, and 18 nucleotides longer than HeV [4]. The additional six nucleotides in NiV-B are inserted in the 5′ nontranslated region of the fusion protein (F) gene. The gene order and sizes of all the open reading frames except V are conserved between NiV-B and NiV-M.
