University College London team captures stunning images that reveal the early steps of heart development, opening doors to better understanding birth defects.
For the first time ever, researchers have recorded time-lapse images that show how the heart begins to form in a mouse embryo. This new footage shows heart cells coming together and forming a heart-like shape just days after the embryo starts growing. The work was done by scientists at University College London (UCL) and offers new hope for understanding how the heart develops and what might go wrong in babies born with heart defects.
“This is the closest and longest we’ve ever observed heart development in a mammal,” said Dr. Kenzo Ivanovitch from the Great Ormond Street Institute of Child Health at UCL. His research team managed to grow mouse embryos in the lab for several days. During this time, they used special imaging tools to track how the heart begins to form in detail.
How Scientists Filmed the Beating Heart Before It Forms
The team used a method called light-sheet microscopy, which helps capture high-quality 3D images without harming the growing embryo. This allowed them to see cells move and interact inside the developing embryo without interruption.
The researchers followed the embryos through a stage called gastrulation. This is the early phase where cells in the embryo start to form the basic layers and axes of the body. Soon after this, heart cells known as cardiomyocytes began forming a small tube. Over time, this tube grows and folds into the full shape of a heart with chambers and walls.
To make this process visible, the scientists used fluorescent markers that made heart cells glow in different colors. Over 40 hours, they took an image every two minutes. The final time-lapse footage shows the cells dividing, moving, and gradually forming a tiny, beating heart.
Cells Move with Purpose, Not Chaos
One of the most surprising discoveries was that the cells did not move randomly. Instead, they followed precise paths. These paths depended on what part of the heart the cells would become—like the upper chambers (atria) or the lower chambers (ventricles).
“We found that heart cell fate and movement are organized much earlier than anyone thought,” said Dr. Ivanovitch. “It turns out what looked like random motion is actually very structured. Cells know where to go and what they will become.”
This finding is very important. It suggests that problems with heart formation may begin earlier than expected. Understanding this could help doctors find new ways to prevent or treat congenital heart defects, which affect about 1 in every 100 babies around the world.
A Step Toward Growing Hearts in the Lab
The research could also help scientists who are working on regenerative medicine. That’s the field where researchers try to grow new tissues or organs to replace damaged ones. If we understand how the heart forms in embryos, it may be possible to grow heart tissue in the lab in the future.
Dr. Ivanovitch’s team hopes their work will lead to new studies that use similar imaging methods. By watching how cells move and change in real time, researchers can learn more about how the body builds organs—and how things might go wrong.
More Than Just Mouse Hearts
While this study used mouse embryos, the basic steps of heart development are very similar in humans. Scientists often use mice in early research because they share many biological traits with people. This means the results could one day help improve human health.
The team says the next step is to study how different genes control these early movements. Some genetic mutations might interfere with the order and timing of the cells’ movement. Finding those mutations could help identify the causes of some heart defects before a baby is born.
A Window Into Life’s First Steps
This time-lapse is more than just a scientific achievement. It offers a window into life’s earliest moments. Watching cells come together to build a beating heart is both beautiful and important. It shows just how much happens inside the body before birth—and how fragile that process can be.
The full study was published in the EMBO Journal, a peer-reviewed scientific publication. This journal is known for publishing important discoveries in biology.
This breakthrough offers a fresh way to understand the human heart—how it forms, what can go wrong, and how we might one day fix or even grow one from scratch. With more research, this knowledge could help save the lives of thousands of children born with heart problems each year.