Planar cell polarity and morphogenesis. (360G-Wellcome-096645_Z_11_Z)

Animal development is an everyday miracle that many take for granted. In the last 100 years great progress has been made in understanding one key question: How do cells know where they are in the body information they need to make the right part of the body in the right place (eye, nose, heart). But there is another aspect of animal design which is just as important but remains mysterious. If a some cells make a finger, they need to build it in the right alignment, to attach it to the hand corr ectly and point it in the right direction. To do this each cell needs to know its orientation within the whole; a property known as planar cell polarity. Planar polarity is most obvious in oriented structures, such as the whorls of hair on a baby's head. However it is probably even more important inside the body; for example in orienting nerve outgrowth so as to wire the nervous system correctly. Our project is to understand the mechanism of planar polarity. We use the fruitfly because the mecha nisms are universal, the same genes being used in flies and in us, and because the fruitfly is excellent for genetic experiments.