What are telomeres, that three American scientists solved a problem for in cell biology?
A telomere is a region of repetitive DNA at the ends of chromosomes, which protects the end of the chromosome from destruction. Its name is derived from the Greek nouns telos (τἐλος) “end” and merοs (μέρος, root: μερεσ-) “part”. A Russian theorist Alexei Olovnikov was the first to recognize (1971) the problem of how chromosomes could replicate right to the tip, as such was impossible with replication in a 3’ to 5’ direction. To solve this and to accommodate Leonard Hayflick’s idea of limited somatic cell division, Olovnikov suggested that DNA sequences would be lost in every replicative phase until they reached a critical level, at which point cell division would stop.[1][2] During cell division, the enzymes that duplicate the chromosome and its DNA cannot continue their duplication all the way to the end of the chromosome. If cells divided without telomeres, they would lose the end of their chromosomes, and the necessary information it contains. (In 1972, James Watson named this pheno
Stockholm (ANTARA News/Xinhua) – Elizabeth H. Blackburn, Carol W. Greider and Jack W. Szostak, all from the United States, won the Nobel Prize for Medicine on Monday. The trio were awarded the prize for the discovery of “how chromosomes are protected by telomeres and the enzyme telomerase,” the Nobel jury — the Nobel Assembly at Sweden`s Karolinska Institute — said in a statement. The Nobel Laureates of 2009 have solved a major problem in biology: how the chromosomes can be copied in a complete way during cell divisions and how they are protected against degradation, the statement said, adding that the solution is to be found in the ends of the chromosomes — the telomeres — and in an enzyme that forms them — telomerase. The winners of the physics prize will be announced on Tuesday, to be followed by those for chemistry on Wednesday, literature on Thursday, peace on Friday and economics next Monday. The annual Nobel Prizes are usually announced in October and are handed out on Dec.
The Nobel Prize in Physiology or Medicine was awarded this year to three American scientists who solved a problem of cell biology with deep relevance to cancer and aging. The three will receive equal shares of a prize worth around $1.4 million. The recipients solved a longstanding puzzle involving the ends of chromosomes, the giant molecules of DNA that embody the genetic information. These ends, called telomeres, get shorter each time a cell divides and so serve as a kind of clock that counts off the cell’s allotted span of life. Sources: http://www.nytimes.com/2009/10/06/science/06nobel.html?
