Villin expression in the visceral endoderm and in the gut anlage during early mouse embryogenesis.

Abstract

Villin is an evolutionarily well conserved, Ca2+ regulated actin‐binding protein, and a major structural component of the brush border of specialized absorptive cells. Using paraffin sections and an affinity purified polyclonal anti‐villin antibody, we have investigated the early expression of villin during mouse embryogenesis. Villin is first detectable at the early post‐implantation stage in visceral endodermal cells at the periphery of the egg cylinder. In this extra embryonic layer, the expression of villin increases and then persists until full term gestation. In the embryo, villin first appears in gut anlage during the axial rotation. Using the same methodology, villin expression is also demonstrated in differentiating embryoid bodies from a teratocarcinoma. Both in extra embryonic and embryonic extracts, villin expression is confirmed by immunoblot and Northern blot analysis which reveal, respectively, a single polypeptide of 93 kd and an mRNA of 3.4 kb in length, two well defined parameters for adult mouse villin gene expression. The results presented here show that paraffin sections allow very sensitive and highly resolutive detection of antigens in early embryogenesis. They provide a detailed developmental profile of villin expression and demonstrate the usefulness of villin as a marker for epithelial cells involved in absorptive processes.

Villin: A marker for development of the epithelial pyloric border

“…The answer to this question can have important implications with regard to the possible molecular mechanisms that act to set this distinct epithelial boundary. Our results extend earlier in situ and immunocytochemical studies that documented villin expression in the early gut tube and in kidney and gonad primordia (Maunoury et al, 1988(Maunoury et al, , 1992Ezzell et al, 1989). In addition, we observed ␤-galactosidase activity as well as endogenous villin protein expression in the developing auditory system, where it had not been previously documented.…”

“…Villin is an actin bundling protein that is found in many absorptive epithelia. Importantly for these studies, villin is expressed in the presumptive small intestinal epithelium several days before intestinal villi appear (Maunoury et al, 1988(Maunoury et al, , 1992Ezzell et al, 1989). During further tissue patterning and villus formation, villin is up-regulated.…”

Critical roles of type III phosphatidylinositol phosphate kinase in murine embryonic visceral endoderm and adult intestine

“…Our objective in this study was to disrupt PipkIII in intestinal epithelial cells (IECs), the cell type in adult mice that is most similar to embryonic VE cells in terms of polarized morphology and absorptive function. To this end, we crossed PipkIII flox/flox mice with transgenic mice expressing Cre under the control of the villin promoter (VilCre) (21,22) to generate VilCrePipkIII flox/+ mice. When VilCrePipkIII flox/+ mice were crossed to PipkIII flox/flox mice, VilCrePipkIII flox/flox mice were recovered at a lower than expected Mendelian frequency (Table S1).…”

“…When VilCrePipkIII flox/+ mice were crossed to PipkIII flox/flox mice, VilCrePipkIII flox/flox mice were recovered at a lower than expected Mendelian frequency (Table S1). Based on our observations of the PipkIII neo/neo embryos, we suspected that the lethality of the conditional mutant was due to VilCre-mediated disruption of PipkIII in VE cells during embryogenesis (21). To test this hypothesis, we crossed VilCre mice with Rosa26-floxed-stop-EYFP (R26R-EYFP) mice (23) and followed Cre-mediated excision of the floxed gene through detection of the reporter gene product EYFP.…”

Both BMP4 and serum have significant roles in differentiation of embryonic stem cells to primitive and definitive endoderm

“…In mouse embryo, Villin is first expressed in the primitive endoderm and then in the visceral endoderm. During development of definitive endoderm and in adults, Villin is expressed in the intestinal epithelium (Maunoury et al 1992(Maunoury et al , 1988. Plf gene, which is exclusively transcribed in the tro- phoblastic giant cells (Lee et al 1988), was also expressed in all the experimental groups (Fig.…”