Table 2

S-phase kinetics in E2-treated wt and Igf1-null mice

LI1LIcumInflux Efflux
EpiStroMyoEpiStroMyoEpiStroMyoEpiStroMyo
wt50.6 ± 1.513.2 ± 1.89.8 ± 2.264.8 ± 2.315.0 ± 1.511.9 ± 1.314.3 ± 0.91.8 ± 0.42.1 ± 1.117.7 ± 3.47.9 ± 2.64.9 ± 1.9
Igf1−/−58.5 ± 4.815.3 ± 3.16.0 ± 1.072.5 ± 3.517.6 ± 3.98.4 ± 0.714.0 ± 1.72.5 ± 1.02.4 ± 1.022.6 ± 4.68.4 ± 1.73.2 ± 0.9
  • The cumulative labeling index (LIcum, all labeled nuclei/total nuclei) is equally increased over the single labeling index (LI1, 3H-labeled nuclei/total nuclei) in E2-treated Igf1−/− and wt mice, showing that S-phase duration is equal in the two groups. A further estimate of S-phase duration, given by the percentage of double-labeled nuclei (simultaneously BrdUrd and 3H-positive) also was equal in both groups (data not shown). S-phase influx, represented by the percentage of BrdUrd-only positive nuclei, and efflux, represented by 3H-only positive nuclei, also are equal in the two groups. All data are given as mean ± SEM (percentage of all nuclei for each cell type). There were 3–6 mice in each group, and no statistically significant differences were found for any comparison between the two genotypes. Abbreviations are as in Table 1