Telomere DNA Sequences and the Concept of Ontogenetic Reserve Cells
D. M. Spitkovsky1
1Research Center for Medical Genetics, Russian Academy of
Medical Sciences, ul. Moskvorech'e 1, Moscow, 115478 Russia; fax: (095)
324-0702.
Submitted July 17, 1997.
Dynamics of telomere sequences are considered in normal and immortalized
cells. Immortalized cells are suggested to be derived mainly from a
special subpopulation of ontogenetic reserve cells. Their epigenetic
program consists of autoregeneration during external stimulus for
genome reorganization and corresponding appearance of genetic variants
of cells. It is suggested that cells surviving the crisis stage contain
a special signal sequence integrated into telomere DNA. Its elimination
during shortening of DNA telomere sequences in dividing ontogenetic
reserve cells is a signal for the cooperative transition of chromatin
into a new steady state that corresponds to the epigenotype of
immortalized cells. Localization of telomere DNA sequences in
intrachromosomal "hot points" reflects phylogenetic
rearrangement of the genome.
KEY WORDS: telomere, telomere DNA, ontogenetic reserve cells,
chromatin phenotype, cooperative transitions, DNA loops, nuclear
matrix, epigenetic state, chromosomal "hot points".