Cloning and partial characterization of the xanthine dehydrogenase gene of Calliphora vicina, a distant relative of Drosophila melanogaster.

In vitro enzymatic assays have shown that an enzyme with typical xanthine dehydrogenase (XDH) activities and electrophoretic mobility slightly different from that of Drosophila XDH is present in Calliphora tissues. A Calliphora genomic sequence has been isolated by low-stringency hybridization to the Drosophila rosy gene (XDH), and partially sequenced. This sequence has been shown to be unique, polymorphic, and it maps on chromosome I. Sequence comparisons provide compelling evidence that it belongs to the XDH gene of Calliphora. Interspecies transformation experiments, aimed at investigating functional as well as structural divergence of the XDH genes of Calliphora and Drosophila, are now possible.