Human breasts grown on mice

Biomedical researchers have found a way to grow human breast tissue on the chests of mice-complete with milk ducts. The purpose is to gain a better understanding of cancer. Scientists normally use genetically engineered mice to study the disease, but mouse cancer is slightly different from our own, so this method should give researchers a more accurate picture of what goes on in the development of breast cancer. Previous work on breast cancer in mice only involved the grafting of one type of breast cell, but this study is the first time biologists have been able to graft both main types of human breast cells into mice-epithelial cells, which line the milk ducts, and support cells called fibroblasts.

-Zoe Cormier
Source: Nature

Mars once wet and salty

NASA reported on Tuesday that the rover Opportunity may be exploring an area that was once covered in salt water. Rippled patterns in the rocks near the rover indicate that the rocks were shaped by the currents of water and not simply by wind. This is the first time scientists have found clear evidence of water on the surface of Mars as opposed to below ground level. The water was probably at least five centimeters deep, and flowed about a speed of 10 to 50 centimetres per second. Chemical deposits in the area suggest that the water was salty like the primordial seas on earth, lending further support to the idea that the planet once harboured life.

-ZC
Source: NASA

Small jaws for big brains

A hot new theory in human biology suggests that our ancestors were able to evolve massive brains because their jaws shrunk. Researchers found that a certain muscle protein is much smaller in humans than in other primates, resulting in relatively weak muscles. It would seem that a genetic mutation resulting in weaker jaw muscles worked in our favour, so to speak, by forcing the jaws to shrink and thus freeing up skull space and allowing the brain to expand threefold. Moreover, the gene for this muscle protein appeared at about the same time that we did, lending support to the controversial theory.

-ZC
Source: Science