Researchers rewire the genetics of E. coli, make it virus-proof


Many of the fundamental features of life don’t necessarily have to be the way they are. Chance plays a major role in evolution, and there are always alternate paths that were never explored, simply because whatever evolved previously happened to be good enough. One instance of this idea is the genetic code, which converts the information carried by our DNA into the specific sequence of amino acids that form proteins. There are scores of potential amino acids, many of which can form spontaneously, but most life uses a genetic code that relies on just 20 of them.

Over the past couple of decades, scientists have shown that it doesn’t have to be that way. If you supply bacteria with the right enzyme and an alternative amino acid, they can use it. But bacteria won’t use the enzyme and amino acid very efficiently, as all the existing genetic code slots are already in use.

In a new work, researchers have managed to edit bacteria’s genetic code to free up a few new slots. They then filled those slots with unnatural amino acids, allowing the bacteria to produce proteins that would never be found in nature. One side effect of the reprogramming? No viruses could replicate in the modified bacteria.

Source: Researchers rewire the genetics of E. coli, make it virus-proof | Ars Technica



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Source: 小红书6月4日微博发问后账号被封,遭中国网信办调查 – 华尔街日报

Early adopters of Chinese vaccines see case surges; China plows ahead anyway


The dramatic ramp up comes at an awkward time, however. Early adopters of China’s vaccines have seen dramatic surges in COVID-19 cases—despite high vaccination rates—and are now backing away from the country’s offerings.

In Bahrain, for instance, officials are now offering high-risk people who have already received two doses of China’s Sinopharm vaccine a third vaccine dose—but one made by Pfizer-BioNTech. The apparent vote of no confidence by officials is striking: Bahrain was one of the first countries to back and rollout Sinopharm’s vaccine, and it has had a highly successful vaccination campaign. Nearly 58 percent of the Persian Gulf country has received at least one dose of a vaccine, and most of the vaccines given in Bahrain are from Sinopharm. But the country is now seeing its worst wave of COVID-19 yet and the government has recently issued a two-week lockdown to try to get transmission under control.

The Seychelles went through a similar struggle. The archipelago saw a dramatic spike in cases in mid-May, despite having around 70 percent of its population vaccinated with at least one dose. Like Bahrain, the Seychelles had largely relied on the Sinopharm vaccine.

Dubai, which has also relied on Sinopharm’s vaccine, is now quietly offering residents who have been fully vaccinated with the Sinopharm vaccine the opportunity to get re-vaccinated with the Pfizer-BioNTech vaccine, according to The Wall Street Journal.

Source: Early adopters of Chinese vaccines see case surges; China plows ahead anyway | Ars Technica