This unprecedented feat suggests there could be an alternative to DNA-based life, as we know it on Earth – a genetic system for life that may be possible on other worlds.

This new molecular system, which is not a new life form, suggests scientists looking for life beyond Earth may need to rethink what they are looking for. The research appears in Thursday’s edition of Science Magazine.

DNA is a complex molecule that stores and transmits genetic information, is passed from parent to offspring in all living organisms on Earth, and its components include four key ingredients called nucleotides – all standard for life as we know it. But, what about life on other worlds?

“Life detection is an increasingly important goal of NASA’s planetary science missions, and this new work will help us to develop effective instruments and experiments that will expand the scope of what we look for,” said Lori Glaze, acting director of NASA’s Planetary Science Division.

One way to imagine the kinds of foreign structures found on other worlds is to try to create something foreign on Earth. A team of researchers, led by Steven Benner at the Foundation for Applied Molecular Evolution in Alachua, Florida, successfully achieved the fabrication of a new informational molecular system that is like DNA, except in one key area: The new molecule has eight informational ingredients instead of four.

The synthetic DNA includes the four nucleotides present in Earth life – adenine, cytosine, guanine, and thymine – but also four others that mimic the structures of the informational ingredients in regular DNA. The result is a double-helix structure that can store and transfer information.

Benner’s team, which collaborated with laboratories at the University of Texas in Austin, Indiana University Medical School in Indianapolis, and DNA Software in Ann Arbor, Michigan, dubbed their creation “hachimoji” DNA (from the Japanese “hachi,” meaning “eight,” and “moji,” meaning “letter”). Hachimoji DNA meets all the structural requirements that allow our DNA to store, transmit and evolve information in living systems.

“By carefully analyzing the roles of shape, size and structure in hachimoji DNA, this work expands our understanding of the types of molecules that might store information in extraterrestrial life on alien worlds,” said Benner.

Scientists have much more to do on the question of what other genetic systems could serve as the foundation for life, and where such exotic organisms could be found. However, this study opens the door to further research on ways life could structure itself in environments that we consider inhospitable, but which might be teeming with forms of life we haven’t yet imagined.

“Incorporating a broader understanding of what is possible in our instrument design and mission concepts will result in a more inclusive and, therefore, more effective search for life beyond Earth,” said Mary Voytek, senior scientist for Astrobiology at NASA Headquarters.

One of NASA’s goals is to search for life on other planets like Mars, where there was once flowing water and a thick atmosphere, or moons of the outer solar system like Europa and Enceladus, where vast water oceans churn under thick layers of ice. What if life on those worlds doesn’t use our DNA? How could we recognize it? This new DNA may be the key to answering these questions and many more.

This work also interests those interested in information as part of life.

“The discovery that DNA with eight nucleotide letters is suitable for storing and transmitting information is a breakthrough in our knowledge of the range of possibilities necessary for life,” said Andrew Serazin, president of Templeton World Charity Foundation in Nassau, The Bahamas, which also supported this work. “This makes a major contribution to the quest supported by Templeton World Charity Foundation to understand the fundamental role that information plays in both physics and biology.”

The popularity of electronic cigarettes continues to grow worldwide, as many people view them as a safer alternative to smoking. But the long-term effects of e-cigarette usage, commonly called “vaping,” are unknown.

“E-cigarettes are a popular trend, but the long-term health effects are unknown,” says Romel Dator, Ph.D., who is presenting the work at the meeting. “We want to characterize the chemicals that vapers are exposed to, as well as any DNA damage they may cause.”

Introduced to the market in 2004, e-cigarettes are handheld electronic devices that heat a liquid, usually containing nicotine, into an aerosol that the user inhales. Different flavors of liquids are available, including many that appeal to youth, such as fruit, chocolate and candy. According to a 2016 report by the US Surgeon General, 13.5 percent of middle school students, 37.7 percent of high school students and 35.8 percent of young adults (18 to 24 years of age) have used e-cigarettes, compared with 16.4 percent of older adults (25 years and up), Medical Xpress reported.

“It’s clear that more carcinogens arise from the combustion of tobacco in regular cigarettes than from the vapor of e-cigarettes,” says Silvia Balbo, Ph.D., the project’s lead investigator, who is at the Masonic Cancer Center at the University of Minnesota. “However, we don’t really know the impact of inhaling the combination of compounds produced by this device. Just because the threats are different doesn’t mean that e-cigarettes are completely safe.”

To characterize chemical exposures during vaping, the researchers recruited five e-cigarette users. They collected saliva samples before and after a 15-minute vaping session and analyzed the samples for chemicals that are known to damage DNA. To evaluate possible long-term effects of vaping, the team assessed DNA damage in the cells of the volunteers’ mouths. The researchers used mass-spectrometry-based methods they had developed previously for a different study in which they evaluated oral DNA damage caused by alcohol consumption.

Dator and Balbo identified three DNA-damaging compounds, formaldehyde, acrolein and methylglyoxal, whose levels increased in the saliva after vaping. Compared with people who don’t vape, four of the five e-cigarette users showed increased DNA damage related to acrolein exposure. The type of damage, called a DNA adduct, occurs when toxic chemicals, such as acrolein, react with DNA. If the cell does not repair the damage so that normal DNA replication can take place, cancer could result.

The researchers plan to follow up this preliminary study with a larger one involving more e-cigarette users and controls. They also want to see how the level of DNA adducts differs between e-cigarette users and regular cigarette smokers. “Comparing e-cigarettes and tobacco cigarettes is really like comparing apples and oranges. The exposures are completely different,” Balbo says. “We still don’t know exactly what these e-cigarette devices are doing and what kinds of effects they may have on health, but our findings suggest that a closer look is warranted.”