A paradox in biology is that our hearts begin to beat before they're fully formed. This video shows young heart cells as they start to beat out the rhythm that will last a lifetime. Scientists captured this activity in real-time at around ten hours after fertilisation, by using advanced microscope techniques. They labelled individual cells in the embryos of mice, then tracked each cell’s growth and movements. This showed that early heart cells cluster in two groups. Cells in the first group are quick to begin beating, while those in the second help the first cells to move into place along a tube-shaped structure (shown here). Once there, both groups beat in unison. The tube pumps blood and will ultimately develop into the heart’s four chambers. It’s the alternating roles of the two groups of cells that allows the heart to function before it is fully developed.
Written by Deborah Oakley
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.