A Monoclonal Antibody That Reacts with the Ventro-Caudal Quadrant of Newly Formed Somites

In the late nineteenth century and continuing into the twentieth century, embryology textbooks frequently portrayed somites in a saggital plane showing a distinct morphological difference between the rostral and the caudal portions of the somite. These portrayals were most prominent in the chapter dealing with the development of the spinal cord, and the differences were associated with spinal nerves. It was not until the 1980s that these differences were examined in closer detail. One of the first instances of correlating molecular differences with nerve outgrowth was that of Stern, et al. (1986), who demonstrated a regional specification with relation to the binding of PNA (peanut agglutinin), which localized in the caudal region of the developing somites of chick embryos.