Variability at the Telomeres of the Human X/Y Pseudoautosomal Region
- H.J. Cooke and
- B.A. Smith
This extract was created in the absence of an abstract.
Excerpt
It has been evident for some time that the telomeres (ends) of eukaryotic chromosomes must have properties that fulfill a number of functional requirements. For example, unlike ends of chromosome fragments, telomeres protect the natural chromosome end against fusion with other chromosome ends. They are often associated with the nuclear envelope. They pose a replication problem for the cell since all known DNA polymerases require a primer and synthesize only in the 5′→3′ direction. This implies that without a special structure, only one daughter chromosome would be completely replicated, the other being shortened, compared with the parental chromosome, by excision of a primer. This shortening would occur at each cell division and could presumably not be tolerated beyond a certain point. A number of models have been suggested that circumvent this problem (Blackburn and Szostak 1984).
The molecular biology of telomeres has until recently been confined to yeast and to...
