March 28, 2018

When astronaut Scott Kelly returned to Earth from a year-long mission aboard the International Space Station (ISS) on March 1, 2016, he was a changed man. Literally. Compared to his identical twin brother, fellow astronaut Mark Kelly, there were several noticeable differences. Scott Kelly had grown about 2 inches (5 centimeters) taller in space, and his overall body mass had decreased a bit. However, National Aeronautics and Space Administration (NASA) scientists were most interested in the changes that could not be seen, changes in Kelly’s genetic makeup. And unlike his physical metamorphosis (his body soon resumed its Earthbound proportions), some changes in Kelly’s DNA seem to be permanent.

U.S. astronaut Scott Kelly poses inside the International Space Station in 2015. Kelly’s body and genetic makeup changed during his weightless year in space.

In 2015, Scott Kelly and Russian cosmonaut Mikhail Kornienko began a unique experiment to learn about the effects of long-term space travel on the human body. The pair spent 340 consecutive days on the ISS as part of a study that will help NASA scientists understand the challenges they must conquer if humans are ever to journey to Mars and beyond. Kelly and Kornienko orbited Earth more than 10,000 times speeding at 17,500 miles per hour (28,165 kilometers per hour) while floating in the weightlessness of microgravity (a condition of very low gravity). During this time, they experienced the stresses and solitude of long-term space flight and were exposed to cosmic radiation above the protective filter of Earth’s atmosphere.

NASA astronaut Scott Kelly (left) and Russian cosmonaut Mikhail Kornienko pose during training at NASA’s Johnson Space Center prior to their year in space. Credit: Bill Stafford, NASA

For experimental control, Scott’s brother Mark remained on Earth. As Scott’s identical twin brother, Mark’s genetic makeup is exactly the same as Scott’s. After Scott returned, NASA scientists studied the twin brothers. Any differences between Scott and Mark could be seen as the effects of the long-term space travel.

The growth spurt that Scott Kelly experienced in orbit turned out to be short-lived and he soon shrank back to his normal height as he returned to Earth’s gravity. But NASA scientists were surprised to find that Scott’s DNA, the genetic material that makes up his genes, was now significantly different from his twin. They found that about 7 percent of Scott’s genes, including those involved in bone formation, DNA repair, oxygen use, the immune system, and eyesight, had altered function when compared to Mark’s genes. Many of these genetic changes appear to be permanent.

NASA scientists think that Scott’s long-term mission in space altered his DNA through processes called epigenetics. Scientists have long known that environmental factors can alter how genes are expressed (how they function) in organisms through epigenetic processes. These processes are not mutations, nor are they physical changes in the DNA. Rather, the processes change how a particular gene functions. Various factors may switch a particular gene on or off or otherwise change how it is expressed. Such environmental factors include nutrition, exposure to certain chemicals, and stress. Scott and Mark remain genetically identical twins, but some of Scott’s genes are now expressed differently compared to Mark’s because of his time in space.

April 23, 2013

The United States Supreme Court recently heard arguments challenging the legality of  patenting genes. The case concerns patents granted to Myriad Genetics, a biotechnology company based in Salt Lake City,  for isolating two human genes–BRCA1 (breast cancer type 1 susceptibility protein) and BRCA2 (breast cancer type 2 susceptibility protein) in 1994 and 1995, respectively. Mutations in these genes increase the risk that a woman will develop certain types of cancers. The court’s decision could have a profound impact on medical and genetic research in the United States, affecting everything from the development of life-saving drugs and medical tests to genetically modified crops.

A patent is a document issued by a government granting an inventor exclusive rights to an invention for a limited time. The invention must be new, useful, original, and not easily discovered or created.

Chromosomes, made up of long strands of tightly coiled DNA, generally occur in pairs. This photograph shows 12 of the 23 pairs of chromosomes that occur in most human body cells. Copyright L. Willatt, Photo Researchers

Genes determine which characteristics living things inherit from their parents. One complete set of human genes is called a genome. Scientists have found that the human genome is made up of about 25,000 genes. Since 1982, patents have been granted in the United States for more than 4,000 human genes. A patent on a gene gives the company that discovered it exclusive rights to produce drugs, diagnostic tests, or other tools based on that gene.

Myriad Genetics was the first group to isolate the BRCA genes. They discovered that women who inherit mutations in the BRCA1 and BRCA2 genes have a significantly greater lifetime risk of developing breast and ovarian cancer than women who do not. Because Myriad holds a patent on these genes, doctors must purchase a blood test developed by Myriad to determine if a patient has the mutated version of either gene. Each test costs  about $3,000 dollars. In addition, the patent restricts other scientists from conducting their own research on BRCA genes.

The legal case against Myriad Genetics began in in 2009 when plaintiffs filed suit against the company. The plaintiffs in this case included researchers, patients and cancer survivors, breast cancer and women’s health groups, and scientific associations, all of which are being represented by the American Civil Liberties Union (ACLU) and the Public Patent Foundation. In 2010, a New York court ruled that the patents on the BRCA genes were invalid. Myriad Genetics appealed, and after several cases, the U.S. Court of Appeals ruled that human genes can be patented. This decision is now being appealed to the Supreme Court.

Attorneys for Myriad Genetics claim that companies should be allowed to own the discoveries they make through a patent. They claim that private companies will have no incentive to conduct important scientific research if they cannot profit from the results.

The plaintiffs argue that human genes are products of nature. Every cell in every person has copies of the BRCA genes. Under U.S. patent law, such products of nature may not be patented. The plaintiffs claim that such patents actually prevent useful scientific research because they restrict other scientists from conducting research on patented genes.

The Supreme Court’s decision on this case is expected in June 2013.

 Additional World Book articles:

• Gene (Special report-How Genes Cause Disease)
• Genome (Special report-What’s Next for the Human genome)