When you suffer a heart attack, a part of your heart dies. Nerve cells in the heart's wall and a special class of cells that spontaneously expand and contract – keeping the heart beating in perfect synchronicity – are lost forever. Surgeons can't repair the affected area. It's as if when confronted with a road riddled with potholes, you abandon what's there and build a new road instead.

The trip to Mars just got a little more difficult now that French researchers have discovered that antibodies used to fight off disease might become seriously compromised during long-term space flight. In a new report published online in the FASEB Journal (http://www.fasebj.org), the scientists show that antibodies produced in space are less effective than those produced on terra firma. The reduced effectiveness of antibodies makes astronauts more susceptible to illness, while increasing the danger posed by bacteria and viruses likely to coexist with wayfaring astronauts.

Jaws made of bone are commonplace in the animal kingdom. However, how jaws developed in the course of evolution is still a mystery. Under the direction of paleontologist Nicolas Goudemand, a team of researchers from the University of Zurich and the European Synchrotron Radiation Facility set about solving this puzzle. Living and extinct jawless animals can yield clues as to the development of the jaw. The researchers studied fossilized conodonts – extinct, eel-shaped animals whose precise relationship with the actual vertebrates is still a matter of debate. For their project, which was funded by the Swiss National Science Foundation and just published in the American journal PNAS, the researchers analyzed new conodont fossils that date from around the biggest mass extinction event at the boundary between the Permian and Triassic periods.

Scientists at Penn State University have achieved a major milestone in the attempt to assemble, in a test tube, entire chromosomes from their component parts. The achievement reveals the process a cell uses to package the basic building blocks of an organism's entire genetic code -- its genome. The evidence provided by early research with the new procedure overturns three previous theories of the genome-packaging process and opens the door to a new era of genome-wide biochemistry research. A paper describing the team's achievement will be published in the journal Science on 20 May 2011.