Antisense attenuation of nestin accumulation causes neural tube deformation in rat embryo cultures

ABSTRACT The roles of nestin in neural tube development were studied using immunostaining and antisense experiments in rat embryos. Nestin was detected in the neural tube of embryos of day 10.5 of gestation (E10.5), while no nestin staining was observed in E9.5 embryos in which the neural plate comprised 3 to 4 layers of neuroepithelial cells. As embryos developed, the neural tube became comprised of multiple cell layers and staining was observed in filamentous structures spanning from the ventricular surface to the pial surface of the neural tube. Nestin accumulation was suppressed in the neural tube of embryos treated with nestin antisense oligodeoxynucleotide (ODN). The treated embryos showed two types of neural tube deformation. One type was a thin neural tube which had 3 to 4 layers of neuroepithelial cells and the other was a local distribution of neuroepithelial cells near the basement membrane. While neuroepithelial cells in the neural tube were fewer in embryos treated with nestin antisense ODN than in controls, the percentage of Islet‐1‐positive neurons relative to the neuroepithelial cells was not different between the treated and control embryos. These results suggested that nestin plays roles in the proliferation of neural tube cells and in the formation and the maintenance of multiple cell layers in the neural tube but not in suppression of development of Islet‐1‐positive neurons.