Eukaryotic cells undergo arrest and enter apoptosis in response to short telomeres. T cells
from late generation mTR-/-mice that lack telomerase show increased apoptosis when
stimulated to enter the cell cycle. The increased apoptosis was not inhibited by colcemid,
indicating that the response did not result from breakage of dicentric chromosomes at
mitosis. The damage response protein γ-H2AX localized to telomeres in metaphases from T
cells and fibroblasts from mTR-/-cells with short telomeres. These data suggest that the …