DIGITtally-a new tool for streamlining and simplifying Drosophila melanogaster meta-analysis

Drosophila melanogaster has one of the deepest research bases within the life sciences, with a wealth of high-quality tissue- and cell type-specific transcriptomic data available. However, integrating large datasets derived from disparate sources is not trivial. We have designed a broadly applicable solution to this problem in the form of the Drosophila Interesting Genes in Individual Tissues-tally (DIGITtally) system. It is freely available online at www.digittally.org. DIGITtally is customizable and hypothesis-free, allowing meta-analysis across the Drosophila research space along with analysis of conservation in other species, querying 10 data sources for seven indicators of tissue-specific activity. We have applied DIGITtally to a pertinent question within entomology-that is, whether a specific pattern of gene expression underlies the transporting activity of epithelial tissues (an 'epitheliome'). By using DIGITtally to survey gene expression throughout the tissues comprising the D. melanogaster alimentary canal (salivary gland, midgut, Malpighian tubules, and hindgut), we have verified the existence of a specific 'epithelial' vacuolar-type ATPase configuration.