Transposition as a mechanism for maintaining telomere length in Drosophila
- National Institute of Environmental Health Sciences, Research Triangle Park, NC (United States)
- Univ. of California, Irvine, CA (United States)
Telomeres are structures at the termini of linear chromosomes that serve to maintain the stability of those ends. Several functions have been attributed to telomeres, at least two of these are vital. The vital functions are (a) to {open_quotes}cap{close_quotes} the natural chromosome ends in order to distinguish them from broken ends and, thus, to protect them from recombination, repair, and degradation, and (b) to maintain chromosome length by periodic elongation and, thus, to counteract the inability of DNA polymerases to replicate linear chromosomes completely. While very little is known about capping, the mechanisms of telomere elongation in a number of organisms are being elucidated. Several models for elongation have been proposed. Recent evidence suggests that two of these may operate in different organisms or under different conditions. In many species elongation is accomplished by the interaction of two telomeric DNA repeats. The repeating unit is generally 6-8 basepairs (bp) long and guanine-rich on one strand. The sequence of the repeating unit is evolutionarily conserved, being very similar in ciliated protozoa, flowering plants and vertebrates. The second component is an enzyme, telomerase, that adds more copies of the repeating unit at the terminus. Telomerase resembles reverse transcriptases in structure and carries an associated RNA that is used as a template for the telomere extension.
- OSTI ID:
- 28438
- Report Number(s):
- CONF-9210475-Cond.; TRN: 95:001845-0012
- Resource Relation:
- Conference: NATO advanced research workshop, Crete (Greece), 10-15 Oct 1992; Other Information: PBD: 1993; Related Information: Is Part Of Chromosome segregation and aneuploidy; Vig, B.K. [ed.] [University of Nevada, Reno, NV (United States). Dept. of Biology]; PB: 429 p.
- Country of Publication:
- United States
- Language:
- English
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