From Newsgroup: talk.origins

https://www.nbcnews.com/science/science-news/space-travel-may-accelerate-aging-stem-cells-much-10-fold-study-says-rcna228614

Astronaut cells seem to age faster in space. They probably have to look
at the effects of cosmic ray bombardment. Google says that the cosmic
ray dose on the surface of the earth is only 2 to 3 mSv a year while the astronauts on the space station are exposed to 80 to 160 mSv during a 6
month stay on the station (40 years worth of cosmic ray radiation in 6 months). I did undergraduate research in a maize genetics lab, and
another maize geneticist that my research professor knew had gotten a
project onto skylab in the late 1970's. They sent up corn seeds to the
space station and kept them there for a few months. These were a
mutator detection strain. It was heterozygous for a recessive allele
that turned the maize leaves yellow, so any knockout mutation of the
gene would be detected as yellow spots on the leaves (the embryo is a
small target). The plants grown from those seeds were peppered with
yellow spots on their leaves, so the embryos had been mutated hundreds
or thousands of times. This study may not have ever been published. It
meant that we were allowing the astronauts to be blasted. When my
research professor looked into it he found out that the proton
bombardment was expected to produce a shower of ionized molecules as it
passed through a cell, and he started to design an experiment using an accelerator to generate high energy protons so that he would have a
better chance of generating regulatory mutations. I graduated, but I
think that he started working with transposons instead due to their high mutation rate, and you can identify where they land in the genome.

The high energy protons probably do not just affect the cells that they
pass through, but the bodies response to these damaged cells is likely
what they are observing in terms of possible premature aging.

Ron Okimoto

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