science museum

Dividing up the body

An early animal embryo is divided up into blocks, each controlled by Hox genes. These blocks, called somites, later form the body and limb muscles, ribs and backbone. Hox genes make chemical signals, which affect cells in different parts of the embryo in different ways. Once it knows where it is, each cell in the embryo starts to form the correct body part.

The formation of somites in the four-week-old embryo.
The formation of somites in the four-week-old embryo.
The Embryonic Disk (www.ucl.ac.uk/innovations/embryonic)

Science Museum Home Page Who am I? Science Museum Home Page