Body

The life cycles of many viruses include a self-assembly stage in which a powerful molecular motor must pack the DNA genome into the virus's preformed shell (the capsid). How it manages this intricate feat has been subject to debate, but we know that the DNA passes into the capsid shell through a channel formed by a structure called the connector. Scientists have speculated that rotation of the connector complex might feed the DNA into the capsid as it turns.

How does the heart attain its characteristic shape? Shape may be sculpted by cell movement, cell division, or changes in cell size and shape, all of which can be influenced by the local environment. The heart appears as a simple tube early in development; later, the tube walls bulge outward to form the cardiac chambers.

The current battle between the makers of anti-wrinkle products – widely compared with the Coke and Pepsi struggle for superiority – is receiving an injection of scientific understanding with the release of a new study from the University of Michigan Health System.

North American marine turtles are at risk if global warming occurs at predicted levels, according to scientists from the University of Exeter. An increase in temperatures of just one degree Celsius could completely eliminate the birth of male turtles from some beaches. A rise of three degrees Celsius would lead to extreme levels of infant mortality and declines in nesting beaches across the USA.Marine turtle. Credit: Copyright Lucy Hawkes, MTRG

By first probing the way primitive yeast make cholesterol, a team of scientists has discovered a long-sought protein whose human counterpart controls cholesterol production and potentially drug metabolism.

The collaborative study by investigators at Johns Hopkins University School of Medicine, Vanderbilt University, Indiana University and Eli Lilly Co., was published in the February issue of Cell Metabolism.

The harmful environmental effects of livestock production are becoming increasingly serious at all levels—local, regional, national and global—and urgently need to be addressed, according to researchers from Stanford University, the United Nations Food and Agriculture Organization (FAO) and other organizations. The researchers, representing five countries, will present their findings on Feb.

Everyone hopes that one day stem cell-based regenerative medicine will help repair diseased tissue. Before then, it may be necessary to decipher the epigenetic signals that give stem cells their unique ability to self-renew and transform them into different cell types.

The hype over epigenetic research is because it opens up the possibility of reprograming cells. By manipulating epigenetic marks, cells can be transformed into other cell types without changing their DNA. It is simply a question of adding or removing the chemical tags involved.

There is an urgent reason to study stem cells: stem cells are at the heart of some, if not all, cancers. Mounting evidence implicates a clutch of rogue stem cells brandishing ‘epigenetic’ marks as the main culprits in cancer. Wiping out tumours for good, some biologists believe, depends on uprooting these wayward stem cells.

Three years ago Mark Kay, MD, PhD, published the first results showing that a biological phenomenon called RNA interference could be an effective gene therapy technique. Since then he has used RNAi gene therapy to effectively shut down the viruses that cause hepatitis and HIV in mice.

When cells become cancerous, they also become 100 times more likely to genetically mutate than regular cells, researchers have found. The findings may explain why cells in a tumor have so many genetic mutations, but could also be bad news for cancer treatments that target a particular gene controlling cancer malignancy.