 Spheroidal particles each have two copies of RNA 4.The nucleotide sequence of the complete genome has been determined and the length of the genome is 8274 nucleotides ( or 9155 including the subgenomic RNA).RNA 1, 2, 3 and 4 are respectively 3644 (3.65kb), 2593 (2.6kb), 2037 (2.2kb) and 881 (0.88kb) nucleotides long.