Know your own mother
Scientists think they now know which gene allows you to recognise your own mother. They bred mice which lacked the gene responsible for producing the brain hormone oxytocin. When compared with normal mice, the "knockout" mice didn't recognise their friends - or enemies, although they were still able to recognise food and remember how to navigate. The study, reported in the July issue of Nature Genetics - timed neatly to the completion of the human genome - could lead to new treatments for autism and schizophrenia.
The eye of the storm
In 1775 a violent storm killed all but 20 of the inhabitants on a tiny island in the Western Pacific. Today, 5% of the 3000 Pingelapese suffer from a rare type of colour blindness and their DNA has helped scientists track down a gene for colour vision. In July's Nature Genetics, the scientists tell how they took DNA from 32 islanders, half of whom had the disorder and spotted a segment of DNA on chromosome 8 that appears in the colour blind inhabitants. The DNA includes a gene responsible for a protein in those eye cells that detect colour. The study "is a beautiful example of the use of isolated populations to study human disease," observes geneticist Val Sheffield.
Saving your liver's bacon
The ancient Greeks were smart. Around 700 BC Hesiod described how each day a giant eagle ate the liver of the chained Prometheus. Each day, he related, the liver replenished itself. We now know how. Scientists from Yale and New York have shown in humans that the new cells do not come from the liver itself, but from stem cells in the bone marrow. For years scientists have debated whether humans have liver stem cells. "The long-held belief has been that bone marrow is supposed toproduce blood cells and liver is supposed to produce liver cells," says Dr Diane Krause. "The goal is now to harness the potential of this exciting find."
