All DNA Nucleic Acid Bases Found in Samples from Ryugu Asteroid

Tokyo, March 17 (Jiji Press)–All five types of nucleic acid bases that make up DNA and RNA were found in sand samples collected from the asteroid Ryugu, according to a paper by a Japanese research team that was published in British science journal Nature Astronomy on Tuesday. The samples were brought to Earth by Japan’s Hayabusa2 unmanned probe. As such nucleobases were also found in samples from the asteroid Bennu, which were collected and brought to Earth by a U.S. unmanned probe, the Japanese team has lauded the latest Ryugu discovery as something that backs a theory that the fundamental ingredients of life came from outside Earth. The team is mainly composed of members of the Japan Agency for Marine-Earth Science and Technology, or JAMSTEC. Both Ryugu and Bennu are C-type, or carbonaceous, asteroids, which contain organic matter and water. They are believed to contain materials from the time of the birth of the solar system within their interiors. In previous studies, uracil, one of the five nucleic acid bases, was detected in samples from Ryugu, and samples from Bennu were found to contain all RNA ingredients, including the five nucleic acid bases and sugar. For the latest study, Toshiki Koga, who is a postdoctoral researcher at JAMSTEC, and other members of the team used water and hydrochloric acid to extract organic substances from about 20 milligrams of Ryugu sand. Further analysis led to the team finding not only the five bases of uracil, adenine, guanine, cytosine and thymine, but also amino acids, urea and other organic molecules, just like in the samples collected from Bennu. “The presence of abundant organic molecules on both asteroids further reinforces the fact that the building blocks of life were commonplace during the formation of the solar system,” Koga said. END [Copyright The Jiji Press, Ltd.]