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Evolution writ small

A unique experiment at Rice University that forces bacteria into a head-to-head competition for evolutionary dominance has yielded new insights about the way Darwinian selection plays out at the molecular level. An exacting new analysis of the exper…

Gene mutations in breast tissue may make cancer detection more difficult

Until now, researchers thought that breast cancer nearly always began when cells in the epithelium went haywire. But new research suggests that genetic mutations can ? and do ? occur initially in a deeper layer of breast tissue, called the stroma. This presents a serious concern for physicians, who believed that breast tumors spread from epithelial tissue. “Genetic alterations in carcinomas, including breast cancers, have always been attributed to epithelial cells,” said Charis Eng, Klotz professor and director of the Clinical Cancer Genetics Program at Ohio State University. She co-authored a new study that looks at genetic mutations in breast tissue.

‘Twin Sister’ mechanism prevents formation of genetic mutations

Twenty thousand hits per day — that’s the average dose of damage sustained by the genes within each cell of our body. How are innumerable mutations avoided? In a new study, researchers have proved the existence of a vital repair mechanism used by cells to correct this damage and showed that it’s responsible for about 85% of what are termed “last-resort” repairs. Genes can be damaged by a variety of factors, such as ultraviolet light, cigarette smoke, or certain types of viruses. Such damage, if left unrepaired, can cause mutations, which can lead to disease. The “first resort” for genetic repair is most often a mechanism that works on an “all or nothing” basis: when unable to precisely correct the damage, it stops in its tracks, leading to what can be an even more harmful effect ? the death of the cell. Fortunately, nature has provided cells with two alternative, last-resort repair systems that can take command when the first rescue mechanism fails.