EARLY EMBRYONIC EXPRESSION OF A 60-KD GLYCOPROTEIN IN THE DEVELOPING NERVOUS-SYSTEM OF THE LOBSTER

To investigate the developmental processes that generate the crustacea n nervous system, we used a monoclonal antibody that recognises an ant igen that is expressed in the developing embryonic nervous system of t he lobster, Homarus gammarus. Expression of this antigen commences ear ly in embryogenesis, occurs in all parts of the embryonic central and peripheral nervous systems, and continues into adulthood. Initial expr ession in the central nervous system correlates with the onset of neur onal process outgrowth. Light microscopic analysis shows that the anti gen is found surrounding the cell bodies and processes of all neurons. Biochemical analysis indicates that the antigen is a glycoprotein wit h an apparent molecular weight of 60 kD. Due to the early embryonic on set of its expression, this antigen is a useful cellular label for vis ualisation of pattern formation in the developing nervous system; this is documented in detail for the developing stomatogastric nervous sys tem. The fact that the 60-kD antigen is expressed early in embryogenes is throughout the nervous system suggests that it might play an import ant role in the development of the lobster nervous system. (C) 1994 Wi ley-Liss, Inc.