In untreated mice the mean mutation frequency (Mf) in cauda spermatozoa (29.7±3.7×10−6, n = 6) was significantly lower than that of the liver (58.5±1.9×10−6, n = 3; p = 0.024 (Mann-Whitney), Figures 3 and 4, and Tables 1 and 2).
The principal purpose of this mean is to link the mutation rate of replication to the mean mutation frequency in the progeny population, so the appropriate measure is to average over virions, not infected cells.
Specifically, the absence of mutations in many short and/or imperfect loci, as well as the fact that for five markers only one mutation has been identified, do not allow us to use these results in deriving a mean mutation frequency.
Interesting to note that the unselected TEM-1 libraries of Zaccolo and Gherardi contained a mean mutation frequency of 8.2 and 27.2 substitutions per gene length, however, clones selected on the basis of cefotaxine resisitance showed only 1 11 mutations at the DNA level.
DOI: http://dx.doi.org/10.7554/eLife.02001.019 The top or bottom strand location of the lesions differentially affected their mutagenic effect: repair of top strand T/Gs generated ∼fourfold more mutated episomes than the 0 MM control (respective mean percent mutation frequency 0.107 vs 0.025).
In HNPCC patients aged < 49 years the mean stem cell mutation frequency was significantly lower than in the slightly younger group of patients with Crohn's disease (0.8 +/- 0.9 x 10 -4) vs 3.5 +/- 3.3 x 10 -4), P < 0.01), probably reflecting an increased mutation rate relating to chronic mucosal damage in Crohn's disease.
The tumors from Xuanwei had a mean of 68 mutated genes per tumor, while the CR tumors had a mean of 22. Significantly higher mutation frequencies were observed in 167 genes (i.e., TP53, KRAS) in Xuanwei patients compared to CR patients.
All HIV-1 Env-specific colostrum-derived antibodies were immunoglobulin (Ig G1 isotype and had mean heavy chain complementarity-determining region 3 (CDR3) lengths and mutation frequencies similar to those isolated from blood.
The mutation frequencies in Table 2 are shown as the mean count of EryR colonies per 10 CFU.
