Bioscience News - GEG Tech top picks

The lack of pyrimidine diversity in meteorites remains a mystery since prebiotic chemical models and laboratory experiments have predicted that these compounds can also be produced from chemical precursors found in meteorites. Here the authors report the detection of nucleobases in three carbonaceous meteorites using state-of-the-art analytical techniques optimized for small-scale quantification of nucleobases down to the range of parts per trillion (ppt). In addition to previously detected purine nucleobases in meteorites such as guanine and adenine, they identify various pyrimidine nucleobases such as cytosine, uracil, and thymine, and their structural isomers such as isocytosine, imidazole-4-carboxylic acid, and 6-methyluracil, respectively. Given the similarity in the molecular distribution of pyrimidines in meteorites and those in photon-processed interstellar ice analogues, some of these derivatives could have been generated by photochemical reactions prevailing in the interstellar medium and later incorporated into asteroids during solar system formation. This study demonstrates that a diversity of meteoritic nucleobases could serve as building blocks of DNA and RNA on the early Earth. All DNA/RNA nucleobases were identified in carbonaceous meteorites. Having been provided to the early Earth as a component in carbonaceous meteorites, these molecules might have played a role for the emergence of genetic functions in early life.

Think of life as a house: if DNA molecules are blueprints, then messenger RNAs (mRNAs) are orders, describing the required parts (proteins) and when they should arrive. But putting in many orders doesn’t always mean you’ll get all of the parts on time — maybe there’s a delay with your vendor or delivery service. Similarly, mRNA levels alone do not dictate protein levels

Here, the scientists report a strategy for constructing RNA-only nanodevices to evaluate complex logic in living cells. Their ribocomputing’ systems are composed of de-novo-designed parts and operate through predictable and designable base-pairing rules, allowing the effective in silico design of computing devices with prescribed configurations and functions in complex cellular environments.

Columbia University researchers have created a new topology-based tool that generates a roadmap of the ways in which a stem cell becomes differentiated.

RNA is a fundamental molecule that codes for protein and controls gene expression, playing a part in regulating many cell responses and vital processes. The genetic information contained in premature messenger RNA (mRNA), before being converted to proteins, needs to be processed and cleared of its non-coding sections, known as introns. In several simpler organisms, this key process is carried out by group II introns, enzymes entirely made up of RNA (different from the true protein enzymes) called ribozymes that are able to self-cleave by removing themselves from the mRNA filament and thereby promoting RNA maturation.