Science News August 2017
Science News August 2017
Science News and advances in science, medicine, engineering, technology, mathematics and entrepreneurship so far in 2017. Let us know what you science news you have heard of, seen on the TV, read in newspapers, or found on the Internet. And tell us what has inspired you and made you curious. We will post it on this web site. email us at info@theyoungdarwinian.com for any interesting breakthroughs in your country.
Science news August 2017 – August 30th 3D structure of three-protein complex explains how nerves fire in milliseconds
It is an incredible fact that we can move our arms and legs milliseconds because our nerves can fire within a sub-millisecond timescale. The key to this is a very rapid rise in free calcium at the nerve terminal, which triggers fusion of vesicles containing neurotransmitter. Zhou et al have revealed the 3D structure of the complex at every nerve terminal that does this. The complex is made of SNARE, complexin and synaptotagmin, the latter being the protein that binds calcium. This unlocks the SNARE compex, allowing vesicles ot fuse with the membrane, and release the transmitter. At the nerve-muscle junction, acetylcholine is released, which thentriggers an action potential in the muscle. This flows down the muscle fibre in milliseconds, generating a large rise in free calcium in the muscle cell. This binds to troponin C, which triggers contraction.
Zhou et al. Nature 548, 420-425. The primed SNARE-complexin-synaptotagmin complex for neuronal exocytosis.
For an explanation of how calcium inside a nerve terminal causes it to fire see:
- Campbell, A.K. (2015). Intracellular calcium. Chapter 7, pp 334 -341. Wiley, Chichester
- Campbell, A.K. (2017). Fundamentals of intracellular calcium. Chapter 7.Wiley, Chichester.
- wiley.com/go/campbell/calcium
Science news August 2017 – August 17th Bacterial sensitivity – thirty hours to thirty minutes
When someone has a bacterial infection requiring antibiotic treatment, the first prescription is an educated guess. It can take a few days to confirm that the antibiotic is killing the bacteria. Scientists in Uppsala, Sweden, are working on an exciting new method where E.Coli from urinary tract infection has been accurately diagnosed to be sensitive or resistant to nine antibiotics within 30 minutes. The rod shaped coliform bacteria are trapped in ‘microfluidic chips’ and the growth rate of individual cells monitored. This makes the potential for patients to be accurately diagnosed and treated at the point of care. Better for the patient and better for the global problem of bacterial antibiotic resistance.
Read more at:
Antibiotic susceptibility testing in less than 30 min using direct single-cell imaging. Baltekin et al, Proc. Natl. Acad. Sci. USA, 2017, DOI: 10.1073/pnas.1708558114
Science news August 2017 – August 13th Quark-Gluon plasma
Scientists in New York at the RHIC (Relativistic Heavy Ion Collider) caused heavy gold nuclei, travelling close to the speed of light, to collide. What was produced was quark-gluon plasma, the hottest, least viscous, fastest rotating vortical matter ever produced. The transition of this to hadrons was fundamental to the events soon after the Big Bang. The quark-gluon plasma was predicted to act like a vortex, like water going down a plug, and this has now been observed. Another step forward in our understanding of the strong nuclear force. Captain Kirk would be proud.
Read more at:
Nature 548, pp34-35 and Nature 548 pp62-65
Science news August 2017 – August 11th Insects vs bacteria: which would you back?
Mosquitos are insects and can act as vectors carrying malaria (plasmodium is a protozoan), Zika and Dengue fever (both viruses) amongst other horrible diseases. Malaria alone leads to about half a million deaths per year, and economic devastation of affected regions. A tiny island in the South Pacific has been almost cleared of the mosquito, beaten by bacteria. Scientists discovered that when infected by the Wolbachia bacteria, and a high proportion of them are, the mosquito eggs will not mature if the male and female were harbouring different strains of the bacteria. Result – Bacteria 1, Insect nil.
Read more at:
Mosquitos meet their match in Tahiti Nature, 548, pp17-18
Science news August 2017 – August 11th Genetic disease – cure is a step closer
The gene defect leading to the condition, Hypertrophic Cardiomyopathy, has been corrected in viable human embryos. The disease causes the heart muscle to thicken and can result in fit young athletes suddenly collapsing. It is dominantly inherited so only one copy of the gene is needed to lead to the disease. The technique used was to edit the gene that carries the mutation, MYBPC3. The enzyme CAS9 was used to cut the genome, then specifically designed CRISPR components inserted. These embryos were not implanted, but the work, carried out in the USA, will give hope to families carrying this mutant gene, and other families known to carry different gene defects.
Read more at:
Ma, H. et al Nature http://dx.doi.org/10.1038/nature23305 (2017)
Science news August 2017 – August 11th Altering the genome of a human embryo.
This is possibly the greatest ethical challenge in genetic medicine today. Work is advanced in Sweden and the UK to understand developmental biology. In China research has already lead to altering disease related genes in human embryos, which could protect against HIV infection. The latest research into changing the genome and potentially preventing Hypertrophic Cardiomyopathy was done in the University of Portland in the USA. If it works as designed, it would be amazing. However caution is required as this sort of technique could lead to problems if the embryo was allowed to develop into a baby. The first is the possibility of making other unintentional genetic changes and the second is if mosaics are made so different embryonic cells contain different sequences. The scientific advance from the USA reduces the chance of both these unwanted events happening thus bringing safer genetic medicine a step closer.
Read more at:
CRISPR fixes embryo error Nature 548, (03 August 2017) doi:10.1038/548007a.Gene editing research in human embryos gains momentum Nature News 532,289-290.Liang, P. et al. Protein Cell 6, 363–372 (2015).
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