CAMBRIDGE, MA -- DNA is made from four nucleosides, each known by its own letter -- A, G, C, and T. However, since the structure of DNA was deciphered in 1953, scientists have discovered several other variants that are often added to the DNA sequences to replace one of the usual four letters.

These variants, which may be modified versions of the traditional nucleosides, often help cells to control which genes are turned on and off, and are referred to as "epigenetic marks" in the DNA. In bacteria, they can also protect DNA from invasion by other organisms such as viruses.

reaggregation of marine sponges' cells helped the scientists to come closer to understanding of the origin and early evolution of multicellular animals.The work was published in Journal of Experimental Zoology Part A: Ecological Genetics and Physiology.

Andrey Lavrov and Igor Kosevich, MSU biologists, researched the ability of the cells of marine sponges (Porifera) to reaggregation - a process, during which the artificially separated sponge cells reaggregate and build multicellular aggregates of varying types.

Unlike illicit trade in drugs, guns or pornography, illicit trade in rare wildlife doesn't have to hide on the 'darknet' because people can find whatever rare species they want in the open marketplace.

The so-called darknet is not required for trade in species such as rhino or elephant, because laws protecting wildlife trade online are so poorly enforced, research by the University of Kent suggests.

In an article entitled Assessing the extent and nature of wildlife trade on the darknet, published in Conservation Biology, the lack of darknet markets was compared to the burgeoning trade on the open web, which researchers say indicates a lack of successful enforcement there.

The modern plagues of obesity, physical inactivity and processed food have been definitively established as modern causes of colon cancer. Researchers have also associated a mutation of the Adenomatous polyposis coli (APC) gene with the deadly disease. But which came first? Is colon cancer a lethal product of modernity? Or is this an open-and-shut case of DNA gone awry?

A new Tel Aviv University discovery suggests that a genetic predisposition to colorectal cancer preceded the advent of modernization -- and, in a bizarre twist, they discovered this evidence in an 18th-century Hungarian mummy.

Have you ever cut into a potato to find a dark spot or hollow part? Early research shows that these defects are likely the result of calcium deficiencies in the potato -- and that tuber calcium is genetically linked to tuber quality.

Neither consumers at grocery stores nor the companies that make potato chips and fries want these low calcium defects. In addition to the cosmetic issues, these potatoes are more likely to rot.

Most farmed varieties of potatoes have naturally low levels of calcium. So researchers at the USDA-ARS and University of Wisconsin-Madison, including Shelley Jansky, John Bamberg, and Jiwan Palta looked to wild potatoes. Their purpose: to breed new potato cultivars with high calcium levels.

Health officials, drug companies, governments and the public are scrambling to understand and combat the Zika virus. The virus was first identified almost 70 years ago, but little is known about it. And now, officials suspect it could be related to a rise in microcephaly cases in affected countries. An article in Chemical & Engineering News (C&EN), the weekly newsmagazine of the American Chemical Society, details the scientific challenges ahead.