RNA world easier to make : Nature News

An elegant experiment has quashed a major objection to the theory that life on Earth originated with molecules of RNA.

John Sutherland and his colleagues from the University of Manchester, UK, created a ribonucleotide, a building block of RNA, from simple chemicals under conditions that might have existed on the early Earth.

The feat, never performed before, bolsters the ‘RNA world’ hypothesis, which suggests that life began when RNA, a polymer related to DNA that can duplicate itself and catalyse reactions, emerged from a prebiotic soup of chemicals.

“This is extremely strong evidence for the RNA world. We don’t know if these chemical steps reflect what actually happened, but before this work there were large doubts that it could happen at all,” says Donna Blackmond, a chemist at Imperial College London.

See on www.nature.com


The Origin of Life » American Scientist

As the frontiers of knowledge have advanced, scientists have resolved one creation question after another. We now have a pretty good understanding of the origin of the Sun and the Earth, and cosmologists can take us to within a fraction of a second of the beginning of the universe itself. We know how life, once it began, was able to proliferate and diversify until it filled (and in many cases created) every niche on the planet. Yet one of the most obvious big questions—how did life arise from inorganic matter?—remains a great unknown.

jlinzel‘s insight:

For task 1 of the new school year. 

See on www.americanscientist.org

Regenerated kidneys filter urine!

See on Scoop.itIB Biology

Researchers at Massachusetts General Hospital (Boston) have successfully regenerated kidneys that were unsuitable for transplantation. They stripped the tissue of all native cells, then added donor stem cells to the scaffolding that was left behind.

jlinzel‘s insight:

How about this, on a different note, remove all original cells from a damaged kidney and use donated stem cells to regenerate the cellular companents. Then try it! Sounds like a gasget repair in an engine. Crazy enough it worked. I wonder how many times it needed to be tried before it finally worked. I need to find the original paper for this. Next stop – made to order organ replacements. Then, brain transplants with uploading all original memories. 

See on scienceblogs.com

Human Infection with a Novel Avian-Origin Influenza A (H7N9) Virus — NEJM

See on Scoop.itIB Biology

Original Article from The New England Journal of Medicine — Human Infection with a Novel Avian-Origin Influenza A (H7N9) Virus

jlinzel‘s insight:

One of the first papers published on H7N9. OUt of Beijing. What surprised me is the analysis was done so quickly using kits and an automated sequencer. Tech has gone crazy. All that had to be done with tremendous amount of labour just 20 years ago. 

See on www.nejm.org

Avian influenza H7N9 viruses isolated from humans: What do the gene sequences mean?

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There have been over 60 human infections with avian influenza virus H7N9 in China, and the virus is spreading in that country.

jlinzel‘s insight:

So far the most informative blog post [but done by an esteemed virologist] about the phylogeny of H7N9 as well as the genetic mutations that allow it to do what it does. Absolutely CRAZY how much they already know. If you don’t already know whtat H7N9 refer too I have a couple good posts at www.scoop.it My IB’s will re using this soon to characterize the mutations in DNA and resulting AA changes. 

See on www.virology.ws

First human infections with avian influenza H7N9 virus

See on Scoop.itIB Biology

Fourteen people in China have been infected with avian influenza H7N9 virus, which has never been isolated from humans.

jlinzel‘s insight:

Ok IB students here is a classical and modern genetic topic! All influenza strains begin in birds. It is an 8 stranded RNA virus. The strands are linear RNAs that if two or more viral particles infect the same cell the new viral packages have the potential to ‘reassort’ the 8 RNA strands leading to a new strain of influenza. There are 3 major groupings [Genus] of influenza: A, B, C. The strain in Shanghai is the H7N9.

The H refers to a glycoprotein [a protein with sugars atatched to it] on the envelop [phospholipid bilayer] of the viral particle [not all viral particles have an envelop – influenza obviously do]. The Heamagluttinin glycoprotein does 2 things: 1) allows the viral particle to bind to sugars on the surface of your cells [usually lung when you breathe them in] and 2) stimulate fusion of YOUR cell membrane with the VIRAL envelope membrane allowing the viral particle to fuse and enter YOUR cell. There are 17 types of hemagglutinin known and each one has different affinities to different sugar combinations on your cells. Some strains infect birds, or pigs, or bats or other creatures because they have different sugars on their cells than we do. But the viruses mutate and evolve. Those able to infect new hosts have a selective advantage and are naturally selected. 

The N refers to neuraminadase. This enzyme is needed for new viral particles to be released from the infected cell. The neuraminidase enzymatically breaks the attraction of NEW hemagglutinin molecules from the cells glycoproteins allowing the NEW viral particles to be released. There are obviously many neuraminidase enzymes – hence the N9 in this case. 

I could continue with more interesting aspects of influenze but I might have my IB do a project on it. Obviously its a hot topic in Shanghai right now.

See on www.virology.ws