Table 2 Frequency of mutations
Blumenstiel et al. (2009)aGerhold et al. (2011)1 Lane (23× Coverage)2 Lanes (50× Coverage)
EMS Concentration45251515
Mutation Rate (kb/Mutation)2739794.0 (±22.4)124.6 (±21.8)
False-Positive Rate (%)17.6<255.3b2.8b
  • A comparison of the mutation rates (nonparental single nucleotide variants) reported in different studies as kb/mutation. Errors represent ± 1 SD. We found a higher mutation frequency than Blumenstiel et al. (2009), and a similar frequency to that reported by Gerhold et al. (2011; on a different chromosome arm) reported using mutagenesis with 25 mM EMS, a higher concentration than that used in our study. As recorded in Table 1, when total variants were recorded the frequency of variants predicted decreased significantly (P < 0.05) after deeper sequencing, suggesting that there may be a higher frequency of false positives when sequencing depth is lower, although this was not seen for coding variants. Mutation frequencies for our study and the Gerhold et al. (2011) study were calculated using the +BDGP release five reference sequence (dm3) that was the alignment template for all these studies.

  • a Based on 70.9% of the genome sequenced after filtering.

  • b These false-positive rates were determined for coding variants (see Results section on identification of mutations).