CHD refers to a range of issues, including anomalous coronary artery, where the coronary arteries are malformed.

 CHD refers to a range of issues, including anomalous coronary artery, where the coronary arteries are malformed.

 These arteries supply the heart with oxygenated blood, so if they are not properly developed then it can cause sudden and dangerous complications. But not all species have this problem. There are animals including fish and amphibians whose hearts don't have or need coronary arteries. So why do we and where did they come from?

To help answer these questions, researchers in Japan compared the development of blood vessels in the hearts of mice, Japanese quails, newts, zebrafish, sharks and frogs. The work is published in the journal eLife.

The team used a combination of techniques, including MRI, micro-CT scans, sectioning (analyzing thin slices of the hearts under a microscope) and 3D reconstruction, to create detailed images. By comparing these images, they could see the difference in how the blood vessels (vascular system) develop in the hearts of amniotes, i.e., mammals, birds and reptiles, and non-amniotes, i.e., fish, sharks and amphibians, from embryos to adults.