According to a new study, healthy “space puppies” were born from frost-dried mouse sperm that orbited the planet for nearly six years on the International Space Station (ISS).
DNA damage radiation on the ISS 100 times stronger From above Earth.. Radiation is even more powerful beyond the ISS, which is still protected from some radiation by the magnetic fields of our planet.
“Before the advent of the space era, it is very important to investigate the effects of cosmic radiation not only on living things but also on future generations,” the authors write in a treatise. “Space radiation can cause DNA damage to cells and concern the inheritance of mutations in progeny after deep space exploration.”
If human sperm are similarly elastic in space and the Earth becomes inhabitable in the future, lyophilized sperm can potentially play a role in the regrowth of space colonies.
Relation: Sexy Swimmer: 7 Facts About Sperm
Climate change and a potential apocalyptic future will allow humans to cross the boundaries of our planets and look at planets and satellites that may live in space. Researchers are trying to understand whether cosmic radiation can harm mammals and other animals. DNA And make it impossible Reproduce We will keep humanity alive.
However, the authors write that there is no easy way to study the long-term effects of cosmic radiation on biological material. It is difficult to bring living animals and cells to the ISS, the space hub closest to such research. These cells require regular maintenance.
According to the treatise, most of the research done on the effects of cosmic radiation is done under conditions that mimic the universe, not the universe. This is a challenge because cosmic radiation contains various types of energy particles that cannot be reproduced on Earth, such as the solar wind, solar cosmic rays, and galactic cosmic rays.
In a new study, Japanese researchers have discovered a new way to study the radiation of mammalian sperm. Researchers freeze-dried mouse sperm. This is a technology that allows sperm to be stored at room temperature for over a year.
This allowed the team to fire sperm into the ISS without the need for a freezer. According to the paper, dehydrating sperm also kept firing costs low by using “light and small” ampoules to store sperm.
The sperm were launched on the ISS in August 2013, and upon arrival, the astronauts stored the sperm in a freezer at minus 139 degrees Fahrenheit (minus 95 degrees Celsius). Some samples were returned after 9 months, some were returned after 2 years and 9 months, and the last sample was returned after 5 years and 10 months. The longest biological sample is stored on the ISS.
Nine months later, researchers found that sperm DNA and male gamete nuclear damage were slightly higher than in healthy controls, but fertilization and fertility rates were similar, 2017. I reported it in a paper published in the year. Minutes of the National Academy of Sciences..
Long-term space effect
In a new study, researchers examined the remaining sperm samples. They are a “plastic nuclear track detector”, which is a device composed of a polymer sensitive to charged particles, and a “thermoluminescent dosimetry”, which is a device that absorbs and traps radiation energy to grasp the amount of radiation absorbed by sperm. “Measurement” was used. Next, we tested the amount of DNA damage to the sperm nucleus.
They found that sperm absorb about 0.61 millisieverts (mSv) / day. By comparison, the NASA limit for astronauts exposed to radiation in low earth orbit is about 50 mSv / year, or 0.14 mSv / day. According to NASA.. Researchers found that the long-term storage on the ISS did not cause significant damage to sperm DNA.
After rehydrating the sperm, they injected it into female mice and found that the mice gave birth to eight healthy puppies. These puppies showed no difference in gene expression compared to controls — 8 puppies born from sperm conserved in the same way on earth.
“So far, this is the only method used to investigate the effects of cosmic radiation on the next generation,” the author writes.
Researchers also found freeze-dried mouse sperm X-ray On Earth, we have discovered that such radiation-exposed sperm can still produce healthy puppies. Researchers say that although there are differences in DNA damage caused by X-rays and cosmic radiation, lyophilized mouse sperm can be stored on the ISS for more than 200 years before becoming non-viable. It was.
Still, it is not yet clear how the results will be transformed into human embryos.
Lyophilized sperm showed “strong resistance” to cosmic radiation. The authors hypothesize that this may be due to a lack of water molecules in frozen cells. Radiation is thought to induce DNA damage through free radicals produced when energy particles interact with water molecules in cells, the researchers write.
Still, the ISS is not a good example of deep space because it orbits within the Earth’s protective magnetic field. Studies show that high-density ionizing particle radiation from deep space can cause more DNA damage in cells. Such experiments can be reproduced, for example, on the lunar orbit platform gateway (unmanned spacecraft) planned by NASA. Month-Orbiting stations, they wrote.
In addition, if this method turns out to be a reliable way to preserve sperm and germ cells, “in the distant future, underground storage of the moon, such as lava tubes, is one of the best places for long-term or permanent preservation. Their very low temperatures, protection from cosmic radiation by thick rock formations, and complete isolation from any disaster on Earth, “the researchers wrote. “These discoveries are essential and important for humanity to advance into the Space Age.”
The findings were published in the journal on Friday (June 11th). Science Advances..
Originally published in Live Science.
Frozen mouse sperm spent 6 years in orbit were used to conceive eight healthy “space puppies”
Source link Frozen mouse sperm spent 6 years in orbit were used to conceive eight healthy “space puppies”