Genetics & Molecular Biology
Polymorphisms are variations in genes which can result in changes in the way a particular gene functions and thus may be associated with susceptibility to common diseases.
In a new study in Psychological Science, psychologist Tina B. Lonsdorf and her colleagues from the Karolinska Institutet in Sweden and the University of Greifswald in Germany examined the effect of specific polymorphisms on how fear is learned and how that fear is subsequently overcome.
You might think that predicting eye color is easy because we all learned in high school about recessive genes and eye color is a great example of those. But it isn't easy. In fact, human eye color, which is determined by the extent and type of pigmentation on the eye's iris, is what geneticists call a 'complex trait, meaning that several genes control which color the eyes will ultimately have. Over the past decades a number of such 'eye-color genes' have been identified, and people with different eye color, will have a different DNA sequence at certain points in these genes.
Researchers have discovered that a long-defunct gene was resurrected during the course of human evolution. This is believed to be the first evidence of a doomed gene – infection-fighting human IRGM – making a comeback in the human/great ape lineage.
The truncated IRGM gene is one of only two genes of its type remaining in humans. The genes are Immune-Related GTPases, a kind of gene that helps mammals resist germs like tuberculosis and salmonella that try to invade cells. Unlike humans, most other mammals have several genes of this type. Mice, for example, have 21 Immune-Related GTPases. Medical interest in this gene ignited recently, when scientists associated specific IRGM mutations with the risk of Crohn's disease, an inflammatory digestive disorder.
Recently, The Frogger and I were watching X-Men: The Last Stand
(aka X-Men 3: Mutants Doing Ridiculous Wire-Work Stunts
), which should get you thinking about what mutant powers you would like to have. Unfortunately, I'd already thought this through in some detail (control of gravity, take a minute to think through the relativistic implications and tremble Homo sapiens
). So, I had time to ponder grander thoughts, like how the hell do they get those mutant powers? Actua
A female moth selects a mate based on the scent of his pheromones. An analysis of the pheromones used by the European Corn Borer (ECB, Ostrinia nubilalis) shows that females can discern a male's ancestry, age and possibly reproductive fitness from the chemical cocktail he exudes.
Jean-Marc Lassance and Christer Löfstedt from Lund University, Sweden, studied the influence of pheromones on mating preferences and carried out an analysis of the composition of the scent and genetic makeup of the animals involved. In addition, they compared the odor bouquet used by males with the scent used by females to attract potential mates.
Women can take pride that they are more efficient than men in many ways, including one that is not so great; storing fat.
It's a paradox women have discussed for generations – their apparent ability to store fat more efficiently than men, despite eating proportionally fewer calories. While it has long been suspected that female sex hormones are responsible, a University of New South Wales (UNSW) research review has for the first time drawn a link between one hormone – estrogen – and its impact on fat storage for childbearing.
Teams of scientists from Australia and the United States have used yeast and mammalian cells to discover a connection between genetic and environmental causes of Parkinson's disease.
Yeasts are single cell organisms, used widely in biological research because their structure resembles that of cells found in animals and humans. Yeasts share many genes, or their functional equivalents, with humans and offer the ability to screen or test thousands of genes and analysing their effects.
A system of opposing genetic forces determines why mammals develop a single row of teeth, while sharks sport several, according to a study published today in the journal Science. When completely understood, the genetic program described in the study may help guide efforts to re-grow missing teeth and prevent cleft palate, one of the most common birth defects.
A major mystery about the origins of life may be resolved if a new hypothesis holds up, says a study published in Nature. Two Université de Montréal scientists have proposed a new idea for how a 'universal molecular machine', the ribosome, might have managed to self-assemble as a critical step in the genesis of all life on Earth.
Plants are obviously essential to our survival and that of most other animals on earth but it is easy to overlook how they have become discretely embedded into our everyday lives; plants provide us with food, medicines, and raw materials used by our industries.
Despite their importance, very few of us could name more than a tiny fraction of the plants that surround us and while most of us could easily between a buttercup and a dandelion (provided both are in flower), only a hand full of experts could identify all 1600 native plants in the UK - and nobody is able to name all of the 250,000 or so plant species recorded world-wide.