[Analysis of a novel delta gene during the formation of cortical layers]

The preplate is composed of earliest-generated neurons, including Cajal-Retzius cells and prospected subplate neurons which together play a critical role in the formation of cortical layers. Additionally, Notch and Delta have been identified as key components that mediate the lateral specification and fate of numerous cells during development. Here, we demonstrate that a divergent type of Delta (D113) is expressed transiently and specifically in a set of earliest generated neurons in the neural tube. Moreover, in developing cerebrum, D113 is specifically and transiently expressed in prospected subplate neurons. Thus, our results suggest that D113 mediates the specification of cell fate in the earliest stage of neurogenesis including the neurons that compose preplate, leading to the mechanism of genesis of cortical layers.