Students Pioneer DNA Research in Space

Elizabeth Reizis and Sophia Chen, winners of the 2017 Genes in Space Competition, at the 2017 ISS Research and Development Conference.

Elizabeth Reizis and Sophia Chen, winners of the 2017 Genes in Space Competition, at the 2017 ISS Research and Development Conference.

April 4, 2018 • By Julia Sable, Staff Writer

Each year, students are making real contributions to science through the Genes in Space program. Two student researchers watched their ideas for innovative DNA research in space become reality as their experiments launched to the International Space Station (ISS) on SpaceX CRS-14 as part of the Genes in Space-5 payload.

The Genes in Space program, founded by Boeing and miniPCR and supported by the ISS National Lab, holds an annual student research competition in which students in grades 7 through 12 propose pioneering DNA experiments that use the unique environment of the ISS. The winning proposals are developed into flight projects that are sent to the space station. After reviewing 375 student proposals, Genes in Space announced the 2017 winners of the U.S. competition last July in an unprecedented tie: high school students Elizabeth Reizis from New York and Sophia Chen from Washington.

All Genes in Space experiments use a process called polymerase chain reaction (PCR) that makes DNA easier to detect and measure. In labs on the ground, standard PCR machines are large and cumbersome. However, on the ISS, crew members perform PCR using a compact and energy-efficient PCR machine developed by miniPCR. The first experiment to do PCR in space and validate the miniPCR machine was designed by the inaugural Genes in Space student winner, Anna-Sophia Boguraev. The two Genes in Space-5 experiments are similarly innovative and pioneering, testing techniques never before used in space.

What is PCR?

PCR is a common lab technique to amplify (or make many copies of) selected segments of DNA. It’s an essential tool in any DNA research, whether investigators are seeking a cure for cancer or testing forensic evidence in a crime lab.

After extracting DNA from a tissue sample, the DNA is mixed with ultrapure water in a reaction tube. Next, chemicals, including DNA-building enzymes and primer molecules that target specific DNA segments, are added to the reaction tube. The tube goes into a PCR machine, which repeatedly heats and cools the liquid in controlled cycles. This thermal cycling is important because the enzymes and primer molecules activate at different temperatures. Each cycle builds more copies of the desired DNA segments.

Reizis’ proposal is focused on studying how microgravity affects immune function, specifically the differentiation of immune cells. The differentiation process leaves behind traces in the cells that can be detected using a T-cell Receptor Excision Circles (TREC) assay. Reizis proposed that this type of test could be used on blood samples from ISS crew members to evaluate their immune system function. However, the TREC assay must first be validated onboard the space station to ensure the test works the same on the ISS as it does on the ground, which is what Reizis is aiming to do in her experiment.

What is immune cell differentiation?

Immune cell differentiation happens every time we are exposed to an infectious disease or receive a vaccine. Upon detecting foreign proteins in the body, immune cells multiply quickly, or proliferate, producing a large population of cells that are initially identical but then start to diverge through cell differentiation. The cells change from general-purpose immune cells into specialized cells that do different tasks, such as attaching to and destroying infected cells, releasing chemicals that attract or activate other immune cells, or preserving information about the disease long-term to prevent reinfection. If something slows down the proliferation or differentiation of immune cells, it makes it harder for the body to fight disease.

Chen’s proposal is focused on measuring genomic instability linked to radiation exposure during spaceflight. Although crew members are only exposed to slightly more radiation onboard the ISS than they are back on Earth, radiation exposure will be significantly greater for astronauts traveling to the Moon, Mars, or beyond. Radiation can damage DNA, which could make cells become cancerous. However, scientists are not sure how much damage is really occurring during spaceflight. One way to determine DNA damage is to measure length changes in sections of DNA called microsatellites. Chen’s experiment aims to validate the use of a technique on the ISS that can measure several different microsatellites in a single assay.

The Genes in Space program combines innovative research with educational engagement, pushing the frontiers of genetic research with students at the helm. Looking ahead, the possibilities will grow even more varied and exciting each year as additional tools for DNA analysis are installed on the ISS.