Abstract
Purpose:
To determine the expression patterns of angiogenic factors during anterior eye development. The anterior eye is composed of highly vascularized tissue which surrounds the avascular cornea. We hypothesize that angiogenic factors are expressed in patterns that suggest their potential role during pericorneal vasculogenesis and corneal development.
Methods:
Reverse Transcription PCR (RT-PCR) and RNA in situ hybridization were used to identify spatiotemporal expression patterns of proangiogenic and antiangiogenic factors during anterior eye development and vascularization of embryonic day (E)3, E5, and E7 chick embryos.
Results:
Our data show that secreted proangiogenic and antiangiogenic factors are expressed in developing tissues of the anterior eye including the lens, optic cup, and presumptive iris. Assayed factors represent several gene families known to affect angiogenesis, such as, VEGF, FGF, PDGF, sFlt1, semaphorins, and netrins. Most of these genes are broadly expressed by E3 and then become localized to specific regions of developing tissues in the anterior eye by E7. Receptors for angiogenic factors were localized to angioblasts and forming ocular blood vessels.
Conclusions:
The expression patterns of the proangiogenic and antiangiogenic factors suggest their potential roles in vascular patterning of the developing anterior eye. Our results provide insight into the mechanisms regulating the development of ocular blood vessels and formation of corneal avascularity.
Keywords: 480 cornea: basic science •
436 blood supply