Genes & Cells
Human livers implanted in mice, plus new eye of newt, the potato genome and more in this week’s news
By Science News
New mutations in schizophrenia
New genetic errors crop up more often in people with schizophrenia than in their parents. The results may indicate that many cases of schizophrenia arise spontaneously from the new mutations and are not the result of many inherited genes working in concert. An international group of researchers decoded the genetic blueprints of 14 people with schizophrenia and of those people’s parents. The team examined only protein-producing genes, which constitute a tiny fraction of the genetic instructions, but found 15 new mutations in eight of the people with schizophrenia. People with schizophrenia develop new mutations at more than twice the rate of the average person, the researchers report online July 10 in Nature Genetics. —Tina Hesman Saey
Mice get human livers
The mouse-or-man question just got a little blurrier. Researchers led by Sangeeta Bhatia of MIT engineered artificial livers from human liver cells encased in a polymer scaffold, then implanted the liver packets under the skin or in the abdomens of mice. Mice with the implants can break down drugs and produce liver proteins just like humans do, the team reports online July 11 in the Proceedings of the National Academy of Sciences. Such “humanized” mice could be used to screen drugs and improve therapies for diseases involving the liver. —Tina Hesman Saey
Stroke-be-gone compound
Brains have natural self-healing components that may help protect against and repair damage from a blood-clot-induced stroke. A piece of a protein called perlecan protects brain cells from damage and helps stimulate growth of new blood vessels, all without harmful side effects, an international group of researchers reports online July 11 in the Journal of Clinical Investigation. The bit of protein, called perlecan domain V, restored movement in mice and rats to prestroke levels when administered within 24 hours of a stroke. Since it is part of the brain’s natural response to stroke, the substance could be a safe treatment. —Tina Hesman Saey
Eye of newt regenerates
Shakespeare’s witches may be happy to learn that one of their favorite ingredients is a renewable resource. Newts’ ability to regenerate the lenses of their eyes is not hampered by aging or repeated injury, an international team of researchers reports online July 12 in Nature Communications. Mammals, including humans, lose the ability to renew body parts with age, but newts don’t seem to have that problem. In the new study, newts regrew lenses 18 times in 16 years, with no loss of lens quality. Figuring out how newts regenerate body parts may help improve antiaging therapies for people. —Tina Hesman Saey
Potato genome
Po-tay-to, po-tah-to, however you pronounce it, scientists are now calling the tuber’s genome (mostly) done. Potatoes have 39,031 genes, an international group of researchers known as the Potato Genome Sequencing Consortium reports online July 10 in Nature. Of those, 3,372 genes are unique to potatoes. Analysis of the potato’s genetic blueprints reveals that the plant made duplicate copies of its genetic instructions at least twice in the ancient past. Clues to disease resistance and the evolution of tubers may also be hidden among the genes, and breeders may use the data to build better spuds. —Tina Hesman Saey