Bves is expressed in the epithelial components of the retina, lens, and cornea.

PURPOSE: To demonstrate the expression pattern and subcellular localization of Bves/Pop1a protein, a newly identified cell adhesion molecule, during eye development and corneal regeneration. METHODS: Staged embryonic and adult eyes were assayed using fluorescence immunohistochemistry to detect the Bves protein. A human corneal epithelial (HCE) cell line was used as a model to examine Bves localization during corneal growth and regeneration, with and without antisense morpholino treatment. RESULTS: The data detail the expression and localization of Bves protein before, during, and after differentiation of the eye. In these analyses, Bves was localized to an apical-lateral position in the initial epithelial primordia of the eye. Later, Bves became localized to specific cell types and subcellular domains in the retina, lens, and cornea, indicating changes in Bves expression in the differentiated eye. Finally, an in vitro model of corneal wound healing showed that Bves staining was missing at the epithelial surface during cellular migration across the wound, but it reappeared at points of cell contact during the reinitiation of epithelial continuity. When epithelial sheets were treated with Bves antisense morpholinos to inhibit Bves function, disruption of epithelial integrity was observed. After injury, similar treatment resulted in an acceleration of cell movement at the wound surface but regeneration of an intact epithelium was ultimately impeded. CONCLUSIONS: Taken together, these studies suggest that Bves is expressed in epithelial elements of the developing eye and may have a role in corneal epithelial growth and regeneration.

Xbves is a regulator of epithelial movement during early Xenopus laevis development.

Bves/pop1a is a unique, highly conserved integral membrane protein expressed in embryonic epithelia and striated muscle. Although studies have proposed a role in epithelial morphogenesis, the function of Bves/pop1a in development is completely unknown. Here we show that Xenopus laevis Bves (Xbves) RNA and protein are expressed in epithelia of the early embryo. Transfection of Xbves into nonadherent mouse L cells confers cell/cell adhesion. Global inhibition of Xbves function by morpholino injection into two-cell embryos arrests development at gastrulation by deregulating the epithelial movements of epiboly and involution. Clonal inhibition of Xbves activity within the A1 blastomere and its derivatives completely randomizes movement of its progeny within otherwise normally differentiating embryos. These data demonstrate that Bves/pop1a proteins play a critical role in epithelial morphogenesis and, specifically, in the cell movements essential for epithelial rearrangements that occur during X. laevis development.