Bioscience News - GEG Tech top picks

Nerve cells form long-term memories with the help of an inflammatory response, study in mice finds.

Researchers at Caltech have developed an artificial neural network made out of DNA that can solve a classic machine learning problem: correctly identifying handwritten numbers. The work is a significant step in demonstrating the capacity to program artificial intelligence into synthetic biomolecular circuits.

In research published in the journal Virus Evolution, scientists from Oxford University’s Department of Zoology have revealed that Next-Generation Sequencing and its associated online DNA databases could be used in the field of viral discovery. They have developed algorithms that detect DNA from viruses that happen to be in the blood or tissue sample of the species studied. The research focused on fish genomes as an example, but the method could be used to identify viruses in a range of different species.

Researchers have built a microscope that uses the camera on a cell phone to detect fluorescent products of DNA sequencing reactions in cells and tissues, according to a study published January 16th in Nature Communications. The mobile microscope can detect a point mutation in the KRAS gene that occurs in more than 30 percent of colon cancers.

The field of genetics has seen astonishing breakthroughs and the development of world-changing technologies in the past half century. With such rapid progress, the field has likely raced well beyond the high school biology textbook your class used to study alleles, fruit flies and eye color inheritance.

Researchers at the University of Georgia and at Ben-Gurion University in Israel claim to have demonstrated how nanoscale electronic components can be made from single DNA molecules.

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.

Single-stranded DNA robots can move over the surface of a DNA origami sheet and sort molecular cargoes. Thubagere et al. developed a simple algorithm for recognizing two types of molecular cargoes and their drop-off destinations on the surface (see the Perspective by Reif). The DNA robot, which has three modular functional domains, repeatedly picks up the two types of molecules and then places them at their target destinations. No additional power is required because the DNA robot does this by random walking across the origami surface.

The nuclei of human cells contain 2 meters of genomic DNA. How does it all fit? Compaction starts with the DNA wrapping around histone octamers to form nucleosomes, but it is unclear how these further compress into mitotic chromosomes. Ou et al. describe a DNA-labeling method that allows them to visualize chromatin organization in human cells (see the Perspective by Larson and Misteli). They show that chromatin forms flexible chains with diameters between 5 and 24 nm. In mitotic chromosomes, chains bend back on themselves to pack at high density, whereas during interphase, the chromatin chains are more extended.

Researchers from the University of Cambridge and the MRC Laboratory of Molecular Biology used a combination of imaging and up to 100,000 measurements of where different parts of the DNA are close to each other to examine the genome in a mouse embryonic stem cell. Stem cells are ‘master cells’, which can develop – or ‘differentiate’ – into almost any type of cell within the body.

A team from the University of Leicester has been awarded a prize for their proposal to crack down on wildlife crime using a portable DNA sequencing device, the MinION - developed by Oxford Nanopore Technologies - to read the ‘barcode genes’ of animals affected by illegal trafficking. 

Scientists create a 'synthetic fossil' containing data written in DNA and capable of being preserved for thousands of years.