Down-regulation of the chicken alpha sub(5) beta sub(1) integrin fibronectin receptor during development

We have characterized the diversity of the chicken beta sub(1) integrin family and studied the expression of individual receptors during development. The diversity of the beta sub(1) integrin family was investigated by affinity purifying the beta sub(1) integrins from a variety of adult and embryonic tissues. These purifications reveal the relative levels of expression and also the differential expression of the alpha subunits in those tissues. Monoclonal antibodies were generated against the prominent "band 1" of the embryonic chicken integrins and used to characterize the expression of this alpha subunit in embryonic and adult tissues. This alpha subunit is shown to be the chicken homologue of human alpha sub(5) fibronectin receptor. The chicken alpha sub(5) beta sub(1) integrin is the most prominent beta sub(1) integrin in the embryo and is expressed on the majority of cell types through the day 17 stage.