Biology Current Affairs - 2020
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Researchers from Columbia University Medical Centre (CUMC) in US have converted natural bacterial immune system into the world’s smallest data recorder.
The researchers modified an ordinary laboratory strain of ubiquitous human gut microbe (bacteria) Escherichia coli (E Coli) which enabled it to record their interactions with environment and also time-stamp events.
The microscopic data recorder was created by taking advantage of CRISPR-Cas, an immune system in many species of bacteria. CRISPR-Cas copies snippets of DNA from invading viruses so that subsequent generations of bacteria can repel these pathogens more effectively. To build this microscopic recorder, researchers had modified piece of DNA called plasmid, giving it ability to create more copies of itself in the bacterial cell in response to an external signal.
This research lays groundwork for new class of technologies that use bacterial cells for everything from disease diagnosis to environmental monitoring. It may help to record biological changes taking placing in digestive tract which can yield an unprecedented view of previously inaccessible phenomena. It can be also used in environmental sensing and basic studies in ecology and microbiology, where bacteria could monitor otherwise invisible changes without disrupting their surroundings.
Tags: Biology • Biotechnology • CRISPR-Cas • Science and Technology • US
The Royal Swedish Academy of Sciences has selected Jacques Dubochet, Joachim Frank and Richard Henderson for the 2017 Nobel Prize in Chemistry.
They were selected for developing cryo-electron microscopy for the high resolution structure determination of biomolecules in solution. Chemistry was third of this year’s Nobel Prizes.
Contributions of trio
Richard Henderson in 1990 was successful in using an electron microscope to generate a 3D image of a protein at atomic resolution. Joachim Frank made technology more widely applicable. Jacques Dubochet had helped with vitrification of water, which ensured that biological sample retained its natural shape even in vacuum and while frozen.
The Cryo-electron microscopy is specific type of electron microscopy based on principle of forming three-dimensional (3D) image by collecting and combining thousands of projections of biomolecules. Using it, researchers can now freeze mid-movement of biomolecules and can visualise processes they have never seen.
It helps to make it possible to see biomolecules in 3D after rapidly freezing them at -150°C (i.e. at cryogenic temperature), preserving their natural shape. It can reveal the structure of the molecules of life in exquisite detail. It is decisive for both basic understanding of chemistry and for development of pharmaceuticals.
Significance: Cryo-electron microscopy gives scientists opportunity to look at machinery of life in 3D form. This was not possible with earlier forms of electron microscopes as more powerful beams would destroy biological matter. It allows the study of fine cellular structures, viruses and protein complexes at molecular resolution.