A year in space alters Astronaut’s Gene Expression
Scott Kelly, a retired astronaut with four space flight missions under his belt; returned home from space after a year in March 2016, to find that his genetic sequence has been altered. This was determined by the fact that Scott Kelly’s genetic sequence no longer matched his twin brother’s. To be more accurate, 7% of Scott’s gene expression did not return to normal even after 6 months of his return to Earth. He had also grown 2 inches taller, but this detail has returned to normal.
What needs to be understood is the fact that Scott’s genetic sequence changed with respect to his gene expression, this does not mean that his gene’s themselves have been altered, nor does it mean that his DNA has undergone some sort of mutation. Gene expressions are basically inter-cellular functions, or more simply the genetic sequence is responsible for producing proteins for different body functions and the gene expressions within each cell are what determine which protein needs to be made.
According to Weill Medicine’s Christopher Mason, the man in charge of the analysis, “Nonetheless, this number is likely within the range for humans under stress, such as climbing a mountain, or SCUBA diving.” Meaning that changes in gene expression are not unusual, our gene expressions change every time we get sick. In light of this it can be expected that an astronaut’s gene expression would change, seeing as they have to live in an oxygen deprived environment with increased levels of radiation, for extended periods of time.
The thing to ponder over is the fact that 7% of Scott’s genetic expression did not return to normal, even after being on Earth for 6 months. Another intriguing fact was that while in space Scott’s chromosomes grew longer, at least in his white blood cells. The chromosomes in question are called telomeres that should normally shrink with age, causing the inevitable cellular breakdown from old age. But Scott’s telomeres elongated in space and then quickly shrank to their original lengths when he returned to Earth.
This only confirms the fact that there is a wealth of knowledge beyond our reach but given this case, little by little, we are walking towards it.