Abstract
The genome of infectious bursal disease virus consists of two segments of double-stranded RNA of 2.5 X 10(6) and 2.2 X 10(6) molecular weight. Polyacrylamide gel electrophoresis of purified virus resolved four structural polypeptides: VP-1 (90,000), VP-2 (41,000), VP-3 (35,000), and VP-4 (28,000). Peptide map comparisons of radioiodinated virion proteins indicated no precursor-product relationship between them. The possible relationship between the size of the virus genome and the number and sizes of different viral proteins is discussed.