Purpose:
The purpose of this study was to investigate the presence and the distribution of Cx43 in the developing early human corneal epithelium.
Methods:
Five embryos and eight fetuses (ranged from 10-111 mm crown-rump length (CRL) corresponding to 6th-14th ovulation weeks) were obtained from spontaneous and legal abortions according to the Helsinki Declaration II. By use of an immunohistochemical method Cx43 was identified.
Results:
In week 6, shortly after the lens has detached from the ectoderm, Cx43 is strongly expressed in the ectoderm covering the eye anlage, the early corneal epithelium. In week 7, Cx43 is well expressed in the early corneal epithelium, but in the early conjunctival fornix the expression decreases. In the 14th week, where the limbal and corneal anatomy resemble the post natal anatomy, Cx43 is predominantly expressed in the corneal epithelium and in the conjunctiva, but is absent in the limbal epithelium.
Conclusions:
Previously, Wolosin et al. investigated Cx43 in the developing rat eye and found a characteristic pattern of expression: An early high expression in the detaching lens ectoderm and the following early corneal ectoderm and later expression in the early corneal epithelium and in the conjunctiva but lack of expression in the limbal epithelium. We confirm the dynamic pattern of expression in the developing human eye. This observation indicates the early differentiation of the corneal ectoderm and supports the notion that limbus contains undifferentiated cells and is a stem cell niche.
Keywords: cornea: epithelium • development • differentiation