Human cells display morphological features characteristic of reduced apoptotic function relative to chimpanzee and macaque cells after treatment with MMC.

<p>Cells treated with MMC for 72 hrs were stained with 10 µg/ml of Hoechst 33342 and visualized under a fluorescence microscope. More than 100 cells were examined in 4 separate views (>25 cells per view). The pictures displayed are representative of the overall results. (A) Chimpanzee cells (S006007) untreated (note: untreated human cells display the same phenotype as untreated chimpanzee cells); B) Human cells (AG13153) treated with 10 µM of MMC; C) Chimpanzee cells (S006007) treated with 10 µM of MMC; D) Macaque cells (AG07915) treated with 10 µM of MMC; E) Human cells (AG07307) treated with 15 µM of MMC; F) Chimpanzee cells (S005795) treated with 15 µM of MMC; G) Macaque cells (AG07128) treated with 15 µM of MMC; and H) Human cells (AG13153) treated with 100 µM of MMC. Arrows indicate nuclei displaying an apoptotic phenotype (<i>i.e.</i>, chromatin fragmentation/condensation, C, D, F, G and H). Control cells (A) display a normal cellular phenotype.