NUCLEOTIDE-SEQUENCES OF THE MATRIX PROTEIN GENE OF SUBACUTE SCLEROSING PANENCEPHALITIS VIRUSES COMPARED WITH LOCAL CONTEMPORARY ISOLATES FROM PATIENTS WITH ACUTE MEASLES

Measles viruses isolated from brain cells of patients with subacute sc lerosing panencephalitis (SSPE) have numerous mutations, especially in the matrix protein (M) gene. To find whether the M genes of these SSP E viruses were mutated randomly or in a pattern, we sequenced this gen e from three strains of defective measles virus isolated in Osaka, Jap an. We could deduce the sequence of the possible progenitor measles vi rus for each patient by comparison of the isolate with measles viruses prevailing at roughly the same time and place as the primary infectio n. Biased hypermutation affected the M genes of all three SSPE viruses , although the molecular mechanisms for the mutations might be various . Replacements of U with C in the plus strand accounted for 76% of all mutations in two of the strains, but in the other strain, replacement s of A with G accounted for 52% of the mutations, and the U residues w ere unchanged. (C) 1998 Elsevier Science B.V. All rights reserved.