How effective is medical marijuana, prion-like proteins in bacteria, elucidating imprinting disorders and the scientists behind KO mice dies.
(Nature, 1/12/17, Charles Q. Choi)
For the first time, scientists have detected prion-like proteins in bacteria. Prions are best known for causing the brain-wasting disease known as “mad cow,” but it turns out that a section of a protein in Clostridium botulinum, the microbe that causes botulism, can also behave like a prion when inserted into yeast and Escherichia coli bacteria, researchers reported this week in the journal Science. These findings suggest that prions predate the evolutionary split between eukaryotes and bacteria about 2.3 billion years ago. “Prions are likely to be much more widespread in nature than previously assumed,” Hochschild says. “We believe other prion-forming proteins will be uncovered in bacteria.”
(Science, 1/12/17, Jennifer Couzin-Frankel)
Mysterious genetic defects known as imprinting disorders, which cause stunted growth in some children and runaway growth in others—and a scary array of other complications—have started to come into focus thanks to advances in genomic technology. Imprinting disorders arise in a unique subset of genes in which, after conception, the DNA in the embryo that came from the mother is expressed differently than the DNA from the father. The last several years have seen imprinting disorders emerge from the shadows, and with them a deeper appreciation for the human genome’s ability to modulate gene expression in the earliest stages of development.
(NPR Science, 1/12/17, Patti Neighmond)
Twenty-eight states have legalized marijuana for medical use, but how effective is it? A report published this week by the National Academy of Sciences, Engineering and Medicine found little conclusive evidence in 10,000 studies that suggested cannabis products worked or didn’t work. Part of the problem is that its status as a controlled substance entails so many restrictions that it has been difficult for researchers to do rigorous research on marijuana. The 337-page report did find that there is strong evidence that marijuana reduces pain, particularly muscle spasms or to assuage chemotherapy-induced vomiting.
(The Scientist, 1/12/17, Bob Grant)
Oliver Smithies, the Nobel Laureate honored for his hand in developing tools that could knock out specific genetic components in model organisms, died on Tuesday. Midway in his career, Smithies turned to studying homologous recombination in DNA as a way to explain protein polymorphisms he was detecting in protein serum. Along the way he developed even more tools for studying inheritance, such as novel phage vectors and nucleotide sequencing software. Then in the 1980s, Smithies devised a technique to specifically target single genes and replace them with modified versions. This was a key advance in creating the myriad knock-out and mutant mice models that continue to drive biomedical research. Bradley Popovich, Smithies’ postdoc in the late 1980s, said that Smithies’ ability as a teacher was a logical outgrowth of his drive to innovate. “He did things that others could only dream of, and then he was able to teach others how to do them,” said Popovich, who is now a genomic health strategy consultant at Genome British Columbia.
—Compiled by Senior Scientific Writer Regina McEnery