Ventrally emigrating neural tube cells differentiate into heart muscle

A population of ventrally emigrating neural tube cells has been shown to mi grate along the vagus nerve and contribute to the development of the gastro intestinal tract. Since the vagus also goes to the heart, we sought to dete rmine if these cells migrated into the heart. Neural tube cells were tagged with replication-deficient retroviral vectors containing the LacZ gene, to permanently label their progeny, The virus was microinjected into the lume n of the caudal hindbrain of chick embryos on day 2, Embryos were later pro cessed for the detection of LacZ positive cells, Labeled cells were initial ly confined to the neural tube, Later, they migrated in association with th e vagus nerve into the heart, where they were located in the myocardium. La beled cells were identified as cardiac muscle cells of non-neural crest ori gin, with specific markers. It is concluded that some cardiac muscle cells differentiate from the neural tube cells. (C) 1999 Academic Press.