University of California-San Francisco researchers said the gene, known as Notch, controls whether blood vessels differentiate into arteries or veins during embryonic development, They found Notch is also linked to a vascular disorder in the brain that causes stroke.

The scientists said their findings from an animal model study are the first to provide information on both the progression and regression of a particular disorder known as brain arteriovenous malformation. The disorder causes arteries and veins to be directly connected, rather than through capillaries. That produces vessels prone to hemorrhagic rupture, bleeding and stroke.

The team identified Notch as a potential cause of BAVM because of its role in directing embryonic blood vessel formation.

"The activated Notch gene caused BAVM in all of the mice, making it an unprecedented, potent molecular lesion in the induction of the pathology," said Associate Professor Rong Wang. "Furthermore, we found that repression of the gene in already-ill mice led to their recovery."

The findings appeared in the Proceedings of the National Academy of Sciences.