8
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Accepted
Why did they expect Astronaut Scott Kelley's telomere shortening to accelerate? (they got longer!)
Dr. Bailey wrote a short piece that hints at the reasons behind why she expected what she expected:
Telomeres are the ends of chromosomes that protect them from damage and from “fraying” – much like ...
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5
votes
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Why telomere shortening slowing down cancer?
Think about the 24 different linear chromosomes in a diploid human XY cell. In the absence of active telomerase enzyme to repair the chromosome ends following one round of cell division, then every ...
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4
votes
Does Telomere length shortening with age actually cause our cells to age and stop functioning properly?
Yes
"all somatic cells have a molecular clock that leads them to develop a senescence phenotype" Ruiz et al. 2022
Short telomeres cause replicative senescence. Senescent cells upregulate ...
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4
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Why might long telomeres be selected for in laboratory mice?
Their arguments for increased telomere length in lab mice are:
Rate of tumour formation is dependent on the number of cells within an organism. Additionally, tumours take time to form. Therefore, ...
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3
votes
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Telomeres and daughter strands
Replication doesn't start at the very end of a chromosome, so there is no problem with leading strand synthesis. It's probably easiest to see if the other half of the image was there:
Forgive the ...
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3
votes
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Are nucleotides at the ends of DNA stripped on aging?
The Stanford article that you read is correct, in the sense that telomeres do not need to be completely removed by cell division before deleterious effects occur and cells start undergoing senescence. ...
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3
votes
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What is an "end-to-end fusion" in the context of telomerase?
An end-to-end fusion is the result of two chromosome ends fused together. This happens when telomeres (repeated sequences at the ends of chromosomes) lose their protective telomere-binding proteins. ...
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2
votes
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What organism has the longest Hayflick Limit?
The Hayflick limit is generally associated with telomere length. Human telomeres are a little on the long side as species go, but are not extraordinary. Many species of mice, and other rodents, have ...
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2
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Does Telomere length shortening with age actually cause our cells to age and stop functioning properly?
Yes.
This was demonstrated by showing that re-activation of telomerase (which lengthens telomeres) prevents cell senescence.
The immortal nature of cancer cells can be attributed in large part to ...
- 9,112
2
votes
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Why do tumours need stem cells, when they can generate their own telomerase?
This is like asking why there are multiple forms/mechanisms of dementia when "one would suffice".
To save this from being just a trivial comment, note that the mechanism of elongation ...
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2
votes
The relationship between the shape of the bacterial DNA and the blocking of replication machinery
This has been covered elsewhere (I highly recommend this page ) but it basically has to do with the priming of the strands and the fact that all polymerases work from the 5' prime to the the 3'. I ...
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2
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What is the status of the telomeres in HeLa cells?
Wow. I looked this up on PubMed and there are 906 results for HeLa telomerase. Not all are real, but there's some data to work with here.
I've been reluctant to rely on Russian charity with the Cold ...
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1
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What is the status of the telomeres in HeLa cells?
First, I will address your misconception. You can interpret the telomere length of a typical somatic cell as its upper limit of remaining replication-cycles and therefore as an indicator of its age. ...
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1
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Does Telomere length shortening with age actually cause our cells to age and stop functioning properly?
Yes, it's true in eukaryotes after every cell division telomeres shorten by many base pairs. Telomerase is not found in prokaryotes as their chromosomes are circular. So, no DNA is left out for ...
1
vote
Do telomeres appear at just one end of the chromosome?
This is a great question! The issue- the "paradox" of replication of linear chromosomes- of trying to filling in the unreplicated region (an overhanging 3' end) should technically be an issue only ...
- 11
1
vote
Accepted
Hayflick limit and hair or nails
Let's do some math.
Also, let's ignore your examples, and use a clearer one - instead of fingernails, let's look at the cells that line the intestine. Intestinal epithelial cells are shed and ...
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1
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Telomeres and daughter strands
I think the confusion is coming from the way this picture is drawn. The leading strand does not begin at the end of a chromosome, there is in fact more DNA to the right of your picture that is not ...
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1
vote
Is solving cancer required in order to avoid aging?
Not exactly. However, assuming that we will eventually be able to reverse the effects of aging, cancer formation will become much more rare as a by-product. The explanation for this is a bit involved, ...
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