All embryonic cells thus far examined bear both calcium independent and calcium dependent adhesive systems. The calcium dependent systems are mediated by a family of molecules referred to generically as calCAMs. Dr. Lilien has shown that the calCAMs are divisible into at least two structural types on the basis of their two dimensional peptide maps. One group of calCAMs have peptide maps with over 60% of the spots being similar to N- cadherin related molecules. The second type is represented by L- CAM and shares only 20% of its peptides with the first group. Embryonic chick liver has both a cadherin related molecule, CRM- L and L-CAM. Dr. Lilien proposes to further compare the structure of CRM-L with N-cadherin and L-CAM. To accomplish this he will use molecular genetic techniques isolating cDNA clones of the cadherin related molecules in liver. He will screen liver cDNA libraries with antibodies recognizing all cadherins and oligonucleotide probes based on the known sequences of L-CAM and N-cadherin. Additionally he will attempt to prepare antibodies which are specific to CRM-L. To generate these he will use synthetic peptides chosen from sequence information for immunization of rabbits. These antibodies along with monoclonals will be screened immunohistochemically and ultimately analyzed for their effect on liver cell adhesion. %%% The development of the organs in an embryo involves movements of cells and groups of cells relative to each other. These movements require that cells make and break adhesions with neighboring cells. This proposal is an investigation of a class of molecules potentially important for adhesive interactions between cells.
