An unconventional route for modifying pharmaceutically relevant molecules swaps an atom of carbon for one of nitrogen. The resulting derivatives might open up avenues of research in medicinal-chemistry campaigns.

Echinoderms such as starfish are unusual for their five-fold body symmetry. Maps of gene-expression patterns show how this body plan was acquired, and that the genes specifying head structures do the heavy lifting.

The neural pathways involved in syncope, or fainting, are not well understood. Studies in mice have identified a defined subset of vagal sensory neurons that connect the heart and brain. Stimulation of these neurons causes reduced heart rate, blood pressure, breathing and neuronal activity in the brain, resulting in syncope.

Many human diseases lack accurate mouse models because it is technically difficult to create extensively genetically humanized mice. A technique that allows large stretches of DNA to be rapidly rewritten in mouse embryonic stem cells can be used to produce improved animal models.