Junk DNA goodbye: found, a control over telomeres (Introduction)

by David Turell , Friday, July 23, 2021, 19:04 (1220 days ago) @ David Turell

More junk removed as a segment controlling telomere length is found:

https://www.sciencedaily.com/releases/2021/07/210723105258.htm

"Researchers have recently identified a DNA region known as VNTR2-1 that appears to drive the activity of the telomerase gene, which has been shown to prevent aging in certain types of cells. Knowing how the telomerase gene is regulated and activated and why it is only active in certain cell types could someday be the key to understanding how humans age and how to stop the spread of cancer.

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"Their finding is based on a series of experiments that found that deleting the DNA sequence from cancer cells -- both in a human cell line and in mice -- caused telomeres to shorten, cells to age, and tumors to stop growing. Subsequently, they conducted a study that looked at the length of the sequence in DNA samples taken from Caucasian and African American centenarians and control participants in the Georgia Centenarian Study, a study that followed a group of people aged 100 or above between 1988 and 2008. The researchers found that the length of the sequence ranged from as short as 53 repeats -- or copies -- of the DNA to as long as 160 repeats.

"'It varies a lot, and our study actually shows that the telomerase gene is more active in people with a longer sequence," Zhu said.

"Since very short sequences were found only in African American participants, they looked more closely at that group and found that there were relatively few centenarians with a short VNTR2-1 sequence as compared to control participants. However, Zhu said it was worth noting that having a shorter sequence does not necessarily mean your lifespan will be shorter, because it means the telomerase gene is less active and your telomere length may be shorter, which could make you less likely to develop cancer.

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"Zhu noted that since African Americans have been in the United States for generations, many of them have Caucasian ancestors from whom they may have inherited some of this sequence. So as a next step, he and his team hope to be able to study the sequence in an African population."

Comment: just more evidence there is little 'junk DNA' in our genome. The African white difference shows our human variant types are really somewhat different.