Newborn babies may seem tiny, but even they are giants compared to how they started. It’s sometimes hard to believe that every single one of us began life as a tiny ball of cells less than a hair’s width across. The two mouse embryos pictured are made up of just a few dozen cells (nuclei and membranes stained blue and green, respectively). But they contain all the necessary instructions to make a baby mouse. Every day the cells divide and the embryos grow into something a little more complex. Scientists have taken this detailed snapshot of their growth using fluorescent probes and a powerful microscope. The red specks on the right hand embryo show the locations of a protein called VCL. Lots of cell proteins and signals can be mapped in this way, which can help us understand more about how embryos grow.
Written by Emma Stoye
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.
BPoD is also available in Catalan at www.bpod.cat with translations by the University of Valencia.