Non-muscle Myosin II-A Is Required for the Polarization of Developing Enteroendocrine Cells in Zebrafish Embryos

Abstract: Abstract The epithelium of the gastrointestinal tract comprises multiple cell types， including the enteroendocrine cells， which constitute 1% of the total epithelial cell population. Intestinal enteroendocrine cells are not clustered together but spread as single cell throughout the intestinal tract. The deep internal position of the developing digestive system has made morphological analysis of this organ relatively difficult， particularly at early stages of development. Up to date， the regulation of enteroendocrine cells polarization remains poorly understood. In Tg (nkx2.2a:mEGFP) line， the regulatory elements of the nkx2.2a gene drive strong GFP expression in enteroendocrine cells. Additionally， zebrafish embryos are transparent. Therefore， this line appears to be a good model for study of intestinal enteroendocrine cell development. Here we found that 48~72 h past fertilization (hpf) is an important stage for enteroendocrine cells formation， and 60~72 hpf is an important stage for its polarization. Non-muscle Myosin II-A (NM II-A) gene myh9a and myh9b were expressed in intestinal epithelium during a time window encompassing enteroendocrine cells polarization. Blocking the function of NM II-A by blebbistatin impaired polarization of enteroendocrine cells at a dose-dependent manner. This result suggests that NM II-A is required for the polarization of developing enteroendocrine cells in zebrafish embryos

CSTR: 32200.14.cjcb.2015.03.0003