Medical Research Council - London Institute of Medical Sciences

Now in our 10th year of bringing you beautiful imagery from biomedical science every day

On the Clock

Greater understanding of the genes controlling segmentation in embryonic development

22 January 2021

On the Clock

Insects like beetles have a body made up of different segments. Although you may not realise, human bodies – and those of other mammals – are also segmented, although in a less obvious way. During development in the womb, our spinal column is built from repeated segments known as somites, which are laid down in strict order from top to bottom. Using mouse embryos as a model for humans, researchers have been exploring how this clockwork somite pattern is created. The image on the left is a normal mouse embryo around 8 days after fertilisation. The activity levels of a gene called Hes7 highlighted in different colours from blue (low) through green and yellow (medium) to red (high), with the resulting stripes determining where the somites will grow. The embryo on the right has an alteration in a gene called Fgf4, disrupting the developmental clock and causing serious defects within the body.

Written by Kat Arney

Search The Archive

Submit An Image

What is BPoD?

BPoD stands for Biomedical Picture of the Day. Managed by the MRC London Institute of Medical Sciences the website aims to engage everyone, young and old, in the wonders of biomedicine. Images are kindly provided for inclusion on this website through the generosity of scientists across the globe.

Read More

BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.