Martian Meteorite Shows Presence of Boron that Helps Build RNA
Researchers have now discovered high levels of boron in a Martian meteorite. The oxidized form of boron, called borate, plays a key role in the formation of RNA, according to their study.
The study was conducted by researchers from The University of Hawaii at Manoa NASA Astrobiology Institute (UHNAI), who analyzed the composition of clay found in Antarctica during the 2009-2010 field season. They found that the level of boron in this meteorite is about 10 times higher than in any other meteorite.
"Borates may have been important for the origin of life on Earth because they can stabilize ribose, a crucial component of RNA. In early life RNA is thought to have been the informational precursor to DNA," said James Stephenson, a UHNAI postdoctoral fellow.
Now, biological systems have DNA along with RNA, to pass information from one generation to another. But the most primitive organisms relied only on RNA to deliver the information. One of the most difficult parts about building RNA is to make its sugar backbone, called ribose. Previous research has shown that chemicals present in those times wouldn't be sufficient to help build this ribose without borate.
In the presence of borate, not only is the RNA built easily, but is also stabilized rapidly.
Boron is commonly found in clay sediments found on Earth. This is the first time that researchers have found such a composition of clay in samples from meteorites.
Elements like sulfur, nitrogen, hydrogen, oxygen, phosphorus and carbon in the rock sample analyzed by NASA's Curiosity had previously shown that life could have once been possible on Mars.
"Earth and Mars used to have much more in common than they do today. Over time, Mars has lost a lot of its atmosphere and surface water, but ancient meteorites preserve delicate clays from wetter periods in Mars' history. The Martian clay we studied is thought to be up to 700 million years old. The recycling of the Earth's crust via plate tectonics has left no evidence of clays this old on our planet; hence Martian clays could provide essential information regarding environmental conditions on the early Earth," said Lydia Hallis, a cosmochemist and a UHNAI postdoctoral fellow, according to a news release.
The study is published in the journal PLOS One.