Bad Genes Aren't Always Bad
We usually think of mutations as errors in our genes that will make us sick. But not all errors are bad, and some can even cancel out, or suppress, the fallout of those mutations known to cause disease. Little is known about this process -- called genetic suppression -- but that's about to change as University of Toronto researchers begin to lay out the general rules behind it.
Teams led by Professors Brenda Andrews, Charles Boone and Frederick Roth, of the Donnelly Centre and the Department of Molecular Genetics, in collaboration with Professor Chad Myers, of the University of Minnesota-Twin Cities, have compiled the first comprehensive set of suppressive mutations in a cell, to be published in Science on November 4. Andrews, Boone, Roth and Myers also work together as members of the Genetic Networks program of the Canadian Institute for Advanced Research (CIFAR). Their findings could help explain how suppressive mutations combine with disease-causing mutations to soften the blow of a disease, or even completely protect against it.
It's a curious bit of biology that's only come to light as more healthy people have had their genomes sequenced. Among them are a few, and extremely lucky folks, who dodge the bullet and remain healthy, displaying disease resilience, despite carrying catastrophic mutations that cause debilitating disorders, such as Cystic Fibrosis or Fanconi anemia. How could this be?
"We don't really understand why some people with damaging mutations get the disease and some don't. Some of this could be due to environment, but a lot of could be due to the presence of other mutations that are suppressing the effects of the first mutation," said Roth, who is also a Senior Scientist at Sinai Health System's Lunenfeld-Tanenbaum Research Institute.
Light Drives Single-Molecule
The Rice lab of nanocar inventor and chemist James Tour synthesized light-driven nanocars six years ago, but with the aid of experimental physicists in Austria, they're now able to drive fleets of single-molecule vehicles at once.
A report on the work appears in the American Chemical Society journal ACS Nano.
"It is exciting to see that motorized nanoroadsters can be propelled by their light-activated motors," said Tour, who introduced nanocars in 2005 and motorized them a year later. "These three-wheelers are the first example of light-powered nanovehicles being observed to propel across a surface by any method, let alone by scanning tunneling microscopy."
Rather than drive them chemically or with the tip of a tunneling microscope, as they will do with other vehicles in the upcoming international NanoCar Race in Toulouse, France, the researchers used light at specific wavelengths to move their nanoroadsters along a copper surface. The vehicles have rear-wheel molecular motors that rotate in one direction when light hits them. The rotation propels the vehicle much like a paddle wheel on water.
The team led by Tour and Leonhard Grill, a professor at the University of Graz and formerly at the Fritz-Haber-Institute, Berlin, used wavelength-sensitive modified motors invented by Dutch scientist Bernard Feringa, who shared this year's Nobel Prize in chemistry for his molecular machine.