Science News February 2018

Stop press: Monkeys cloned

Two baby macaque monkeys, Zhong Zhong and Hua Hua, have been born in Shanghai, China. The crazy thing is that they are truly identical, made from cloning using SCNT, Somatic Cell Nuclear Transfer. Dolly the sheep was the first mammal cloned and this has now been achieved in 23 mammalian species. But this is the first time in a primate. The researchers argue that monkeys are needed to study human disease mechanisms, genetic defects and potential therapeutic treatments. The technology used to achieve these live births is very clever but the regulation of use of the technology and the ethics will no doubt be debated long and hard.

Read more at:

Cloning of Macaque Monkeys by Somatic Cell Nuclear Transfer     Cell Volume 172, Issue 4, p881–887.e7, 8 February 2018 Z Liu, Y Cai, et al     DOI: https://doi.org/10.1016/j.cell.2018.01.020 |

 

Clever Clostridium, naïve nutritionists: Another sorry sugar tale

In 2000/2001 a sugar, trehalose was granted safe status in the USA and Europe, and because technological advances made it cheap to make, was added to many foods. Shortly after this, epidemics of serious severe diarrhoea started, caused by the pathogen, Clostridium difficile. Trehalose is a disaccharide that is made of two sugar units, in this case, two glucoses. Surely this cannot cause problems?

Take a clue from nature. The human body evolved coping well with mainly sucrose (glucose and fructose) maltose (glucose and glucose) and babies are very good at metabolising lactose (galactose and glucose). The way the two sugar units link together and the sterioisomerism of the molecules is vital. In the right place, trehalose is an amazing disaccharide that is used by bees for rapid energy and by plants to withstand dehydration, but the human gut has not been exposed to much of it. Two strains of Clostridium difficle have evolved to flourish in very low levels of trehalose. The arguments made by the researchers from the USA, Netherlands and UK are compelling. The moral? Why change the sugars we eat. They are not benign molecules to be messed with.

Read more at:

Dietary trehalose enhances virulence of epidemic Clostridium difficile   Collins C. Robinson et al   Nature volume 553, pages 291–294

 

Reversal of the Earth’s magnetic field

Is this a doomsday scenario?

Everyone who uses a compass knows that the Earth has a magnetic field around it produced by the molten metal at the core of our planet. The compact needle points towards magnetic North, which is different from geographic North. Scientists have discovered that, every hundred thousand years or so, the filed turns upside down. In other words, it reverses. Recent data from satellites obtained by the European Space Agency (ESA) has shown that the next reversal has already started. Some have argued that a complete reversal could be catastrophic, and allow a lethal stream of particles from the sun, and cosmic rays. But NASA says we do not need to worry as the fossil record from times when this occurred before shows that life carried on as normal.

Read more at:

  1. https://www.thesun.co.uk/tech/5478266/earth-magnetic-field-poles-flip-mass-extinction/
  2. http://www.geomag.bgs.ac.uk/education/reversals.html
  3. https://news.nationalgeographic.com/2018/01/earth-magnetic-field-flip-north-south-poles-science/
  4. http://www.dailymail.co.uk/sciencetech/article-5351589/Earths-magnetic-field-flip-upside-down.html

 

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