fate maps: technical notes on the dynamic display

The dynamic fate maps allow you to see which cells in later stage embryos are derived from 16 and 32-cell stage blastomeres. 16-cell blastomeres and their descendants appear in orange when your cursor is passed over them, while 32-cell descendants will appear in blue. This effect is achieved by using javascripts, a simple script that instructs your browser to swap images when the mouse cursor passes over a particular area. For this to work your browser must be able to use javascripts, as later versions of Netscape and Explorer can.

In order for this effect to work quickly, i.e. you do not need to wait for the later stage coloured images to download, the server will download all of the images when you first open the page. Even after the page looks like it has loaded you will see that all of the "swapable" images are still downloading if you look in the bottom left corner of your browser. While these are still downloading only the parts that have already transferred will work. With a fast computer it will take less than 4 seconds for the entire page to download.

Why do only some derivatives of the blastomeres of the 32-cell stage embryo show up in blue on later stages?

This is because of the two dimensional nature of the illustrations. The drawings of the 16 and 32 cell stages show whole embryos (approximately spherical, some cells are closer to you than others), while the images of stage 8 and 10.5 embryos are sections. Only the blastomeres that contribute to the cells in the plane of section shown will appear. For example, the derivatives of 32 C2 will be above or below the plane of section illustrated. We will be working on 3D visualization methods in the future.

To learn about the late derivatives of a blastomere, click on it, and you will be linked to a page dedicated to that particular cells descendants. 16-cell stage is finished, 32-cell in progress...