To further investigate glypican involvement in ethanol response, mutant alleles of the Drosophila glypican genes dally and dlp were investigated to determine whether they alter Drosophila ethanol response. The six mammalian glypican genes have two homologs in the Drosophila genome. Evolutionarily, dally is thought to be orthologous to the human glypican gene paralogs GPC3 and GPC5, whereas dlp is orthologous to the other four human glypican paralogs (Filmus et al. 2008). We tested both genes in Drosophila, reasoning that homologous gene function as measured by something as complex as behavior may not precisely track with the predicted evolutionary lineage of a gene.
