Glycocoding as an information management system in embryonic development

The past 5 years have seen a burgeoning in the amount of data emerging from laboratories studying the early stages of embryogenesis. Much of this data implicates various aspects of glycobiology in the initiation and regulation of these processes. The level of analytical detail coming from these investigations has surpassed our ability to fully understand its overall significance within the context of the interactive/dynamic developmental process. This review proposes a pause in this seemingly endless quest for more detail so that we may take stock of our goals and objectives. The proposed goals include a mechanistic understanding of the process(es) involved in information managed at various 'transition points' during early embryogenesis, and an understanding of the mechanism(s) by which the spatial/temporal regulation of early development are managed. The 'transitions' which occur during cell to cell cluster, cell cluster to early organ architecture, and early organ architecture to functional organ development are fundamental and mirror the evolutionary process of biological information management. All of these 'transitions' involve increasing complexity, the development of hierarchies of information management systems (integrated bidirectionally), and spatial/temporal regulation which relies on historical events to map future structure and function. This review focuses on a relatively small number of studies which highlight these aspects of early development. A mechanism which involves glycocoding, an extension of the Roseman Hypothesis, and its direct use as an information management system is proposed and some supporting experimental evidence is presented. This extension of an existing hypothesis is related to several recent investigations, and is designed to broaden the experimental design of future studies so that these important process issues can be addressed.