Identification of mutations in a temperature-sensitive mutant (tsm5) of murine cytomegalovirus using complementary genome sequencing

Identification of mutations in mutants derived chemically is a difficult and relatively random process. NimbleGen Comparative Genome Sequencing (CGS) was assessed as an inexpensive, rapid method of identifying mutations in the temperature-sensitive mutant tsm5 of the K181 (Birmingham) variant of murine cytomegalovirus (MCMV). This genome resequencing approach requires an established genome sequence as a reference. Comparison of tsm5 and the K181 (Birmingham) variant with the published K181 (Perth) MCMV genomic sequence revealed a total of 10 synonymous and 15 non-synonymous SNPs in tsm5 and 14 of the latter were confirmed by sequencing. Thus, while CGS cannot be relied upon to identify correctly all mutations it was helpful for identifying a large number of mutations for further investigation that could contribute to the ts phenotype of tsm5.