DEVELOPMENT AND ROLES OF COLLAGENOUS MATRICES IN THE EMBRYONIC AVIAN CORNEA

Corneal development requires the production, assembly and sometimes re placement of a number of collagenous matrices. The embryonic chick cor nea is well-characterized and offers certain advantages for studying t he assembly and roles of these matrices. We will first describe the ma trices to be examined. These include the corneal stroma proper, first formed as the primary stroma and subsequently as the secondary (mature ) stroma; Bowman's Membrane; Descemet's Membrane, and the hemidesmosom e of the epithelial cell attachment complex. We will then describe the characteristics of the collagen types involved. including: the fibril lar collagens (types I, II and V), the fibril-associated collagens (ty pes IX, XII and XIV). and the transmembrane collagen of the hemidesmos ome (type XVII). Then, in each subsequent section we will examine in d etail the structure, assembly and development of each collagenous matr ix, and how each specific collagen and/or combination of collagens are thought to provide the matrices with their unique properties. The wor k and views presented here are largely from our own laboratories. Thus , this article is not meant to be a comprehensive review of the litera ture. For pertinent references by others, when possible, we will cite recent reviews. (C) 1998 Elsevier Science Ltd. All rights reserved.