telomere

[ tel-uh-meer, tee-luh‑ ]

noun

1. the segment of DNA that occurs at the ends of chromosomes.

telomere

/ ˈtɛləˌmɪə /

noun

1. genetics either of the ends of a chromosome

telomere

/ tĕl′ə-mîr′,tē′lə- /

1. Either of the sections of DNA occurring at the extreme ends of each chromosome in a eukaryotic cell. Telomeres consist of highly repetitive sequences of DNA that do not code for proteins, but function as caps to keep chromosomes from fusing together. The length of the telomere influences the stability of genetic information just interior of the telomere, since the nucleotide sequences at the ends of a chromosome are not copied by DNA polymerase. Successive copying can thus shorten telomeres, sometimes to the point that functional genes near the telomeres are lost, and this may play a role in cellular senescence and age-related diseases. In germ cells, stem cells, and some cancer cells, shortened telomeres can be extended by the enzyme telomerase , thus keeping both the telomeres and the genes near them functioning. Most somatic cells do not express telomerase, and the shortening of telomeres during each round of cell division may be part of the natural aging of cells.

telomere

1. The long end sequences of a DNA strand occurring at the tip of the chromosomes ; a type of repetitive DNA that usually consists of one hundred to fifteen hundred copies of a single DNA sequence.

Notes

During DNA replication, small parts of the telomere are lost with each cycle. Scientists think that this loss may be related to the aging process.

Word History and Origins

Origin of telomere¹

First recorded in 1935–40

Word History and Origins

Origin of telomere¹

C20: from Greek telos end + meros part

Example Sentences

However, it’s still not clear whether that relationship is causal, and it’s likely that multiple processes affect telomere length.

From Time

Several studies have found that higher levels of physical activity are related to longer telomere lengths in some people, compared to those who are sedentary.

From Time

Subsequently, telomeres returned to near normal length after the astronauts returned to Earth.

From Popular-Science

Quite to our surprise, we saw elongated telomeres in both of the climbing twins.

From Popular-Science

So in the stressful environment of spaceflight, you’d expect telomeres to shrink.

From Popular-Science

Scientists now view telomere length as an overall marker of biological aging.

From The Daily Beast

Harley, 58, is a pioneer in telomere research, and a rigorous scientist.

From The Daily Beast

But it's only now that the medical community is closing in on telomere testing for the average patient.

From The Daily Beast