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lunedì 25 gennaio 2021
# gst: apropos of the structure of natural codes, a RNA folding knot (origami-style) dance
giovedì 20 settembre 2018
# evol: life as a product of molecular self-assembly
<< There are currently two main schools of thought regarding the origins of RNA. In one school, RNA is considered to be a product of nonenzymatic, prebiotic reactions. In the other, RNA is considered to be a product of chemical and/or biological evolution. >>
AA << report progress toward finding a proto-RNA that is the product of molecular self-assembly. >>
Cafferty B.J., Fialho D.M., Hud N.V. (2018) Searching for Possible Ancestors of RNA: The Self-Assembly Hypothesis for the Origin of Proto-RNA. In: Menor-Salvan C. (eds) Prebiotic Chemistry and Chemical Evolution of Nucleic Acids. Nucleic Acids and Molecular Biology, vol 35. Springer, Cham. doi: 10.1007/978-3-319-93584-3_5
https://link.springer.com/chapter/10.1007%2F978-3-319-93584-3_5
Joelle Renstrom. New study identifies possible ancestors of RNA. Astrobiol Mag. Sep 17, 2018.
martedì 14 giugno 2016
# s-gene: a CRISPR-based RNA-targeting approach, the begin ...
<< a new CRISPR system, (..) targets RNA rather than DNA (..), has the potential to open a powerful avenue in cellular manipulation. Whereas DNA editing makes permanent changes to the genome of a cell, the CRISPR-based RNA-targeting approach may allow researchers to make temporary changes that can be adjusted up or down, and with greater specificity and functionality than existing methods for RNA interference >>
Researchers unlock new CRISPR system for targeting RNA. June 2, 2016.
http://m.phys.org/news/2016-06-crispr-rna.html
Omar O. Abudayyeh, Jonathan S. Gootenberg, et al. C2c2 is a single-component programmable RNA-guided RNA-targeting CRISPR effector. Science 02 Jun 2016: DOI: 10.1126/science.aaf5573
http://science.sciencemag.org/content/early/2016/06/01/science.aaf5573
martedì 16 aprile 2019
# evol: the origins of life on earth could be arisen from the same set of DNA and RNA precursor molecules
<< the first living things on Earth may have used both RNA (ribonucleic acid) and DNA (deoxyribonucleic acid), as all cell-based life forms do now. In contrast, the prevailing scientific view—the "RNA World" hypothesis—is that early life forms were based purely on RNA, and only later evolved to make and use DNA. >>
<< These new findings suggest that it may not be reasonable for chemists to be so heavily guided by the RNA World hypothesis in investigating the origins of life on Earth, >>
Ramanarayanan Krishnamurthy. Building blocks of DNA and RNA could have appeared together before life began on Earth. The Scripps Research Institute. April 1, 2019.
https://m.phys.org/news/2019-04-blocks-dna-rna-life-began.html
Jianfeng Xu, Nicholas J. Green, et al. Prebiotic phosphorylation of 2-thiouridine provides either nucleotides or DNA building blocks via photoreduction. Nature Chemistry. doi: 10.1038/s41557-019-0225-x April 1, 2019.
giovedì 26 ottobre 2017
# gene: point code cracking machines (without detectable byproducts)
DNA cracking machine
<< The spontaneous deamination of cytosine is a major source of C•G to T•A transitions, which account for half of known human pathogenic point mutations. The ability to efficiently convert target A•T base pairs to G•C could therefore advance the study and treatment of genetic diseases >>
AA << report adenine base editors (ABEs) that mediate conversion of A•T to G•C in genomic DNA >>
<< ABEs advance genome editing by enabling the direct, programmable introduction of all four transition mutations without double-stranded DNA cleavage >>
Nicole M. Gaudelli, Alexis C. Komor, et al. Programmable base editing of A•T to G•C in genomic DNA without DNA cleavage. Nature 2017 doi: 10.1038/nature24644 Oct 25, 2017
https://www.nature.com/nature/journal/vaap/ncurrent/full/nature24644.html
<< there are virtually no detectable byproducts such as random insertions, deletions, translocations, or other base-to-base conversions >>
Researchers extend power of gene editing by developing a new class of DNA base editors. Oct 25, 2017
https://m.phys.org/news/2017-10-enzyme-rewrites-genome.html
RNA cracking machine
<< RNA Editing for Programmable A to I Replacement (REPAIR), which has no strict sequence constraints, can be used to edit full-length transcripts containing pathogenic mutations >>
David B. T. Cox, Jonathan S. Gootenberg, et al. RNA editing with CRISPR-Cas13. Science. Oct 25, 2017:eaaq0180 doi: 10.1126/science.aaq0180
http://science.sciencemag.org/content/early/2017/10/24/science.aaq0180
Researchers engineer CRISPR to edit single RNA letters in human cells. Oct 25, 2017
https://m.phys.org/news/2017-10-crispr-rna-letters-human-cells.html
Lauran Neergaard. Scientists working toward reversible kind of gene editing. Oct. 25, 2017
https://m.phys.org/news/2017-10-scientists-reversible-kind-gene.html
also:
domenica 25 ottobre 2020
# gst: NikS, a small RNA molecule uses a sort of 'bet-hedging' strategy to survive and infect
venerdì 11 ottobre 2024
# evol: flip of the script when an entity invert code sequences
giovedì 10 gennaio 2019
# drugs: spray with autocatalyic effects: an inhalable form of Messenger RNA
<< Messenger RNA encodes genetic instructions that stimulate cells to produce specific proteins. >>
<< In an advance that could lead to new treatments for lung disease, MIT researchers have now designed an inhalable form of mRNA. This aerosol could be administered directly to the lungs to help treat diseases such as cystic fibrosis >>
Engineers create an inhalable form of messenger RNA. Massachusetts Institute of Technology (MIT). Jan 4, 2019.
https://m.phys.org/news/2019-01-inhalable-messenger-rna.html
Asha Kumari Patel, James C. Kaczmarek, et al. Inhaled Nanoformulated mRNA Polyplexes for Protein Production in Lung Epithelium. Advanced Materials Jan 4, 2019 doi: 10.1002/adma.201805116
https://onlinelibrary.wiley.com/doi/abs/10.1002/adma.201805116
lunedì 19 agosto 2024
# gst: apropos of 'normal' (jazzy?) codes, bacteria encode hidden, free-floating genes outside their genome.
mercoledì 20 aprile 2022
# life: apropos of transitions, a leap from chemistry to biology, the hypothesis of self-assembling droplets, the 'droplet world'.
giovedì 19 maggio 2016
# s-evol: short messages in speciation
<< changes in the sequence and length of four microRNAs [post-transcriptional gene regulators] may be specific to humans. Two were highly expressed in brain tissue and may exert effects on genes with neural functions, while two exhibit restricted expression patterns that the authors posited implied a role in development. The authors also found that "age" might matter; in an evolutionary sense, "younger" microRNAs had less sequence conservation, expression and disease association, and were more isolated than "older" microRNAs. >>
Specific changes to non-coding RNA may be part of what makes us human. May 9, 2016
http://m.phys.org/news/2016-05-specific-non-coding-rna-human.html
<< microRNAs are crucial post-transcriptional regulators of gene expression involved in a wide range of biological processes. Although microRNAs are highly conserved among species, the functional implications of existing lineage-specific changes and their role in determining differences between humans and other great apes have not been specifically addressed. We analyzed the recent evolutionary history of 1,595 human microRNAs by looking at their intra- and inter-species variation in great apes using high-coverage sequenced genomes of 82 individuals including gorillas, orangutans, bonobos, chimpanzees and humans. >>
Gallego A, Melé M, et al. (2016) Functional Implications of Human-Specific Changes in Great Ape microRNAs. PLoS ONE 11(4): e0154194. doi:10.1371/journal.pone.0154194
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0154194
mercoledì 9 agosto 2017
# s-phyto: mRNA instability may facilitate rapid recovery of plants after stressful events
<< Stress recovery may prove to be a promising approach to increase plant performance, and theoretically, mRNA instability may facilitate faster recovery. Transcriptome (RNA-seq, qPCR, sRNA-seq, PARE) and methylome profiling during repeated excess-light stress and recovery was performed at intervals as short as three minutes >>
AA << demonstrate that 87% of the stress-upregulated mRNAs analysed exhibit very rapid recovery >>
Peter Alexander Crisp, Diep Ganguly, et al. Rapid recovery gene downregulation during excess-light stress and recovery in Arabidopsis. The Plant Cell Publ. July 2017 doi: 10.1105/tpc.16.00828
http://www.plantcell.org/content/early/2017/07/13/tpc.16.00828
martedì 7 luglio 2020
# gst: 'transcriptional burst frequency' modulation (more or less noise) during gene regulation
sabato 30 maggio 2020
# gst: apropos of unexpected Hopfion tangles
martedì 15 gennaio 2019
# evol: nonlinear effects in shaping human evolution, the role of viruses
<< Human evolution used to be depicted as a straight line, gradually progressing from an ape-like ancestor to modern Homo sapiens. But thanks to next-generation sequencing, findings in recent years have shown that it wasn’t quite so orderly. Now, a new study is reporting new details about the role of viruses in shaping evolution, in particular, viral interactions between modern humans and Neanderthals. >>
<< Many Neanderthal sequences have been lost in modern humans, but some stayed and appear to have quickly increased to high frequencies at the time of contact, suggestive of their selective benefits at that time, >> Dmitri Petrov
New study reports the role of viruses in shaping evolution. Oct 5, 2018.
https://thesurg.com/virus-shaping-evolution
AA << hypothesized that interbreeding between Neanderthals and modern humans led to (1) the exposure of each species to novel viruses and (2) the exchange of adaptive alleles that provided resistance against these viruses. >>
David Enard, Dmitri A. Petrov. Evidence that RNA Viruses Drove Adaptive Introgression between Neanderthals and Modern Humans. Cell. 175 (2) P360-371.E13 Oct 4, 2018.
mercoledì 26 febbraio 2020
# gst: NS3, how viruses self-cripple their genome replication machinery
mercoledì 15 luglio 2020
# evol: iterative hacking mechanics; a large group of viruses can assemble human-virus codes to produce novel chimeric (UFO) proteins
mercoledì 18 novembre 2015
# s-gene-lab: mammalian genome editing new tech: CRISPR-Cpf1
http://www.sciencedaily.com/releases/2015/09/150925131512.htm
Zetsche et al. Cpf1 Is a Single RNA-Guided Endonuclease of a Class 2 CRISPR-Cas System. Cell, September 2015 DOI: 10.1016/j.cell.2015.09.038
http://www.cell.com/abstract/S0092-8674%2815%2901200-3
<< The Zhang lab offers free online tools and resources for researchers through its website >>
http://www.genome-engineering.org
mercoledì 16 dicembre 2015
# s-gene: shorter than 18 nt
<< (..) current approaches underestimate reproducibly detected RNAs that are shorter than 18 nt [ units of nucleotides ] and theoretical considerations suggest that such shorter RNAs could be used for sequence-specific gene regulation in organisms like C. elegans that have small genomes >>
Blumenfeld AL, et al. Reproducible features of small RNAs in C. elegans reveal NU RNAs and provide insights into 22G RNAs and 26G RNAs. RNA. 2015.
http://www.ncbi.nlm.nih.gov/m/pubmed/26647462/
poeticamente, si potrebbe anche azzardare: << piu' piccolo e' il messaggio, piu' alta sara' la cuspide dell'onda generata ... >> Anonymous, XX e.V.