How can genes for cells change?

[swampwiz]

I was reading about astronaut Scott Kelly's genes having "permanently" changed after a year in 0-G (the key is not that his capsule was in space, but rather that he was at 0-G, but I digress ...) Is it supposed to mean that genes have changed in new cells being born, eventually taking over as the cells with the old genes have died out? And then the genes changed back in the same process?

 

[Drakkith]

His genes did not change. Instead, it was their expression that changed. Cells contain ways to modify the expression of different genes, which enables them to better respond to changing conditions. NASA found that Scott Kelly had significant changes in gene expression thanks to his stint in space, and that 7% of this altered gene expression still had yet to return to normal.

See here: https://www.theverge.com/2018/3/15/...y-dna-scott-kelly-international-space-station

 

[jim mcnamara]

Epigenetics is the study of gene expression - mainly how it can be turned off/on, scaled down or scaled up.

https://www.whatisepigenetics.com/fundamentals/

 

[Andy Resnick]

His genes did not change. Instead, it was their expression that changed. Cells contain ways to modify the expression of different genes, which enables them to better respond to changing conditions. NASA found that Scott Kelly had significant changes in gene expression thanks to his stint in space, and that 7% of this altered gene expression still had yet to return to normal.

See here: https://www.theverge.com/2018/3/15/...y-dna-scott-kelly-international-space-station

Thanks for the link. I hope this effect stimulates a lot more research:

'Upon Scott’s return to Earth, researchers found that his telomeres — the protective caps on the end of DNA strands — were unexpectedly longer than Mark’s telomeres. Scott’s telomeres have since returned to the lengths they were before the ISS mission, but researchers are studying the telomeres of other astronauts to figure how living in space may have caused the caps to grow.'

A colleague of mine studies telomeres:

https://www.csuohio.edu/grhd/faculty/bibo-li