Much of the present interest in vertebrate collagens stems from the important part which these extracellular, structural proteins play in developmental processes and tissue organization as well as from their complex gene structure. So far the only vertebrate collagen genes examined encode the constituent polypeptide (pro α) chains of type I procollagen, that is, the pro α2(I) genes from chicken1,2 and sheep3, and the pro α1(I) gene from mouse4. Recently, we have isolated several collagen-like genomic DNA clones from Drosophila melanogaster5. In addition to providing data on the evolutionary history of this gene family, studying Drosophila has distinct advantages for cytogenetic localization of genes and for defining the functional roles of individual collagens by the application of genetic techniques. Here we compare the hybridization patterns, cytogenetic localization and expression of two of the Drosophila clones, DCg1 and DCg2. Although they are cytogenetically unlinked, they share similar developmental RNA profiles.