Another important project in the lab relates to measurements of time. Almost all the gene expression data which exists about limb development has been recorded from ex-vivo analysis. However, the spatial patterns of certain genes (eg. Sox9) are extremely dynamic – apparently changing hour-by-hour. Knowing the age of a given limb bud should therefore be very important when comparing results, but the field has not had a convenient but accurate method for determining the stage of a limb.

Our lab has therefore created a new staging system which is based on morphometric measurements from the profile of the limb bud. It can determine the stage of a limb to within 2 hours, and we have turned this method into a web-based java application that will soon be openly available to to the whole limb community. Researchers with jpg images of their limb buds can log-on to our web-site and determine an accurate age of the specimen within a few minutes.