Human heart beats using nearly billion-year-old molecular mechanism

We humans have been around for about 2.5 million years, but the beating of our hearts is controlled by something much older than Homo sapiens.

It is an ancient molecular pathway that, according to Huck Institutes faculty researcher Tim Jegla, may be on the order of 700 million to a billion years old.

The Jegla Lab studies the evolution of the nervous and muscular systems, using model organisms such as the cnidarian Nematostella vectensis—also known as the starlet sea anemone—to investigate conserved traits and the molecular pathways and genes that underpin them.

According to Jegla, the starlet sea anemone is in essence an animal that's as evolutionarily far away from humans as possible while still sharing the same neuromuscular signaling systems. Comparisons of humans and cnidarians reveal that only the fundamentally important mechanisms are conserved—such as those required to make a neuron or, in this case, a neuromuscular signal.

In a study recently published in Proceedings of the National Academy of Sciences, the Jegla Lab identified in the Nematostella sea anemone the same gene family (Erg) that is responsible for the slow-wave contractions of the human heart. After cloning the genes for further investigation, the researchers found that the ion channel it encodes has retained its function relatively unchanged since the time of humans' and cnidarians' divergence from their common ancestor almost a billion years ago.