I read somewhere in the internet and wondered if human genes have deactivated immortality genes locked somewhere in the DNA strand. Is this statement true? What does it mean for human lifespan?
In tissue culture and cell engineering fields, the word "immortal" is often used to express something else instead of human or animal life spun. When you take cells from human tissues and grow them in test tubes--although flasks or dishes are used in reality--, cells stop growing after long term culture. They say it is cellular senescence. Several genes actually regulate this cellular senescence, and inactivation of these genes causes infinite cell proliferation. This is immortalization of cells. Then, cells in a human bodies are immortalized, do they get immortal? Probably, not. Cellular senescence partially explains senescence of bodies, but these two are different things. In human bodies, cellular immortalizaion occasionally occur. It is tumor pathologically.
I think you read about the telomerase: https://en.wikipedia.org/wiki/Telomerase
The chromosomes while duplicating, they loose some of the DNA segments from their ends, from the telomer. This is believed to have a direct effect on senescence. The telomerase reproduces the end DNA strip of the chromosomes. This enzyme is found in active form in stem cells and in white blood cells.
The DNA sequence coding this enzyme is found in every cell, but in an inactivated form. Probably the article you are referring to, was talking about the telomerase, because it can be activated in almost every cell in our body. But this can lead to uncontrolled growth of the cells, and when this happens we talk about cancer.
The article probably had a scrap of truth to it. Ageing is not plastic and longevity can be altered in a variety of ways. Although caloric restriction seems to affect longevity the most, there are also longevity genes from a range of cellular processes that have been identified in yeast and mice, indicating that ageing is a whole system process. But none of those genes are "immortality genes". Finding and testing their effects in humans is difficult.
Here is a video on the background on ageing.
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