An Unproven Theorem

Primates were always tree-dwellers Rare ankle bone fossil of oldest-known primate suggests it was arboreal. Matt Kaplan 22 October 2012 The earliest primates seemed to have ankles well suited for life in trees. D. BOYER/DUKE UNIVERSITY Article tools print email rights & permissions share/bookmark Primates love to climb and most make their homes high up in the branches of trees, yet when this habit started has been a contentious issue. Now, the discovery of some ankle bones is making it look likely that primates were arboreal from the very beginning. The earliest primate,  Purgatorius , lived around 65 million years ago and is well known from the same fossil beds in Montana that yield tyrannosaurs just a few metres deeper down. Numerous fossils of the genus have been found but, as is typical with mammals, they have all been teeth that survived owing to the presence of protective enamel. The teeth have provided enough information for palaeo...

Life stresses It is time for sociologists and biologists to bury the hatchet and cooperate to study the effects of environmental stress on how people behave. 10 October 2012 Article tools print email download pdf rights & permissions Share/bookmark In the modern world, 'stress' is too often used as a catch-all word, a vague concept that bundles together a hectic pace of life and the increasing pressures that come with it. To scientists, the fuzzy notion of stress can symbolize the even fuzzier notion of the impact of an environment on an individual — one side of the classic nature–nurture debate. Francis Galton, cousin of Charles Darwin and promulgator of his evolutionary theory, is credited with first defining the terms in this enduring conflict. “Nature is all that a man brings himself into the world; nurture is every influence which affects him after his birth,” he wrote in his 1874  English Men of Science: Their Nature and Nurture . That ...

Rapid test pinpoints newborns' genetic diseases in days Method raises hopes for routine whole-genome sequencing in neonatal intensive care. Monya Baker 03 October 2012 Babies with genetic disorders can have their whole genome screened for muations in just two days. TAYLOR S. KENNEDY/ GETTY IMAGES Article tools print email rights & permissions Share/bookmark A faster DNA sequencing machine and streamlined analysis of the results can diagnose genetic disorders in days rather than weeks, as reported today in  Science Translational Medicine 1 . Up to a third of the babies admitted to neonatal intensive care units have a genetic disease. Although symptoms may be severe, the genetic cause can be hard to pin down. Thousands of genetic diseases have been described, but relatively few tests are available, and even these may detect only the most common mutations. Whole-genome sequencing could test for many diseases at once, but its cost, the comp...

Deadly snake venom delivers pain relief Proteins from the black mamba could inspire painkilling drugs. Helen Shen 03 October 2012 Black mambas have deadly venom containing a mixture of toxins — and two proteins that block pain. V. DONEV/EPA/CORBIS Article tools print email rights & permissions share/bookmark With a series of swift bites, the black mamba injects a toxic cocktail that can kill a human within 20 minutes. But among the compounds that squirt from the snake’s fangs, two proteins can block pain in mice as effectively as morphine — and with fewer side effects, according to a study published today in  Nature 1 . The snake proteins — called mambalgins — were discovered as part of a search for alternatives to opiate drugs such as morphine. Many patients grow tolerant of opiates, requiring higher doses over time, and the drugs often cause side effects such as nausea, constipation and drug dependency. “It’s important to try to devel...

Animals engineered with pinpoint accuracy More accurate genetic modification has created allergen-free cow's milk and pigs that could serve as a model for atherosclerosis.  Amy Maxmen 02 October 2012 A cow in New Zealand has been genetically modified to produce hypoallergenic milk. AGRESEARCH Article tools print email rights & permissions share/bookmark Two genetically engineered farm animals reported today illustrate how far from Frankenstein’s stitched-together monster animal biotechnology has come. One of those animals, a cow, secretes milk that lacks an allergy-inducing protein because researchers accurately blocked its production using the technique of RNA interference 1 . And in pigs, scientists have used an enzyme called a TALEN 2  to scramble a gene that would normally help remove cholesterol. RNA interference (RNAi) and TALENs are more accurate at targeting the gene in question than are earlier genetic engineering techniques...

Custom gene editing rewrites zebrafish DNA Artificial-enzyme method could make model organisms more useful in study of diseases. Nicky Guttridge 23 September 2012 Article tools print email rights & permissions share/bookmark The zebrafish is a major player in the study of vertebrate biology and human disease. Its transparent, externally fertilized eggs, short reproductive cycle and fast growth mean that its embryonic development can be studied closely while the animal is alive, and the fish is a useful model for studying gene behaviour and function. Now, researchers led by Stephen Ekker, a molecular biologist at the Mayo Clinic in Rochester, Minnesota, have for the first time made custom changes to parts of the zebrafish ( Danio rerio ) genome, using artificial enzymes to cut portions of DNA out of targeted positions in a gene sequence, and replace them with synthetic DNA. The work is published today in Nature 1 . Zebrafish are common model organ...

In massive genome analysis ENCODE data suggests 'gene' redefinition Most   people understand genes to  be   specific  segments of DNA that determine traits or diseases that  are inherited. Textbooks suggest that gene are copied (“transcribed”) into RNA molecules, which are then used as templates for making protein – the highly diverse set of molecules that act as building  blocks and engines of our cells.  The truth, it now appears, is not so simple. As part of a huge collaborative effort called ENCODE (Encyclopedia of DNA Elements),  a research team led by Cold Spring Harbor Laboratory (CSHL) Professor Thomas Gingeras, Ph.D.,  today publishes a genome-wide analysis of RNA messages, called transcripts, produced within human  cells. Their analysis – one component of a massive release of research results by ENCODE teams from 32  institutes in 5 countries, with 30 p...