Same Musicians: Brand New Tune

A small ensemble of musicians can produce an infinite number of melodies, harmonies, and rhythms. So, too, do a handful of workhorse-signaling pathways that interact to build multiple structures that comprise the vertebrate body. In fact, cross talk between two of those pathways—those governed by proteins known as Notch and BMP (bone morphogenetic protein) receptors—occurs over and over in processes as diverse as forming a tooth, sculpting a heart valve, and building a brain.

A new study by Investigator Ting Xie, PhD, and his team reveals yet another duet played by Notch and BMP signals, this time with Notch calling the tune. Using mouse genetics, the researchers demonstrated how one Notch family protein, Notch2, shapes an eye structure known as the ciliary body (CB), most likely by ensuring that BMP signals remain loud and clear.

In vertebrates, the CB encircles the lens and performs two tasks essential for normal vision. First, it contains a tiny muscle that reshapes the lens when you change focus, or “accommodate.” And it also secretes aqueous humor into the front compartment of the eye where it helps maintain correct eye pressure. Understanding CB construction is critical, as excessive pressure is one risk factor for glaucoma.

The study was published in the May 15, 2013, issue of the Proceedings of the National Academy of Sciences.