NUCLEOTIDE-SEQUENCE OF THE 5'-TERMINUS OF NEWCASTLE-DISEASE-VIRUS ANDASSEMBLY OF THE COMPLETE GENOMIC SEQUENCE - AGREEMENT WITH THE RULE-OF-6

We have determined the sequences of the 5' ends of three strains of Ne wcastle disease virus, permitting the assembly of the entire genomic s equence, which amounts to 15,186 nucleotides. This length is in agreem ent with the rule of six, which has been shown to determine replicatio n efficiency in similar viruses. Comparison of the extreme 5' end of t he trailer sequence with that of the 3'-terminal leader sequence of th e virus reveals a high degree of complementarity. Variation between th e 5'-terminal sequences of the different strains reveals the presence of alternative L gene polyadenylation signals, leading to correspondin gly different trailer lengths.