FIG. 4.

No detectable change in telomere signal intensity in mVparp^−/− mice and mVparp^−/− mTep1^−/− mice. (A) Telomere signal intensity in mouse thymocytes and splenocytes was analyzed by flow FISH. (Upper panel) Average telomere fluorescence in thymocytes and splenocytes derived from different generations (G₁ to G₅) of mVparp^−/− mice. (Lower panel) Average telomere fluorescence in thymocytes and splenocytes derived from wild-type (WT) and G₁ mVparp^−/− mTep1^−/− (KO) mice. In each set, data were pooled from at least five individual mice (error bars represent standard deviations). MESF, molecules of equivalent soluble fluorochrome. (B) Quantitative FISH analysis of individual metaphases of activated splenocytes derived from wild-type and G₁ mVparp^−/− mTep1^−/− mice. Data were accumulated from approximately 10 metaphases for each histogram. The number of telomeres within a given range of telomeric DNA intensities was plotted against the telomere DNA signal intensity (in arbitrary units: 0 for no telomeric DNA signal and increasing in increments of arbitrary telomere fluorescence units to 161). (C) Representative metaphase spreads of activated splenocytes derived from wild-type and G₁ mVparp^−/− mTep1^−/− mice.