Updates to the Drosophila Anatomy Ontology (DAO)
The Drosophila anatomy ontology (DAO) comprises an organised set of terms describing the wild-type anatomy of Drosophila (Costa et al., 2013). Recent work has focused on adding textual definitions and keeping the ontology up to date with the published literature, resulting in the DAO now containing over 8500 terms, with 76% of these having a textual definition and attribution. Particular emphasis has been made on improving the neuroanatomy, reflecting the progress in this field in recent years: the DAO now includes around 2000 distinct neurons, over 200 lineage clones (including fruitless ones), and the descriptions and nomenclature for the neuropil regions in the adult brain from the BrainName group (Ito et al., 2014).
DAO terms are used in FlyBase to describe phenotypes and expression patterns as shown, for example, on the Gene and Allele Report pages. You can also search for DAO terms directly using our ontology browser, TermLink, by selecting the ‘FlyBase Anatomy (FBbt)’ hierarchy and entering a term of interest. This query retrieves a Term Report that includes the definition of the term, a view of where that term fits within the DAO, and an overview of the number of Gene, Allele, and Insertion records annotated with that term, which are in turn linked to the relevant hit lists. For example, you can see the term report page for the wing disc here.
Extensive work on the DAO in the last 4 years has focused on adding textual definitions and keeping it up to date with the published literature, adding new terms and updating others. This work has produced a rich ontology with 76% of over 8500 terms now having a textual definition and references, in contrast to 25% of over 6500 classes in 2010. We have also added more synonyms to terms, making it easier for users to find a term when different terminologies are used in a specific field.
A particular emphasis of recent work has been the neuroanatomy. This field has grown massively in the last few years thanks to technical advances, enabling researchers to identify and characterize the function of individual neurons. We, in collaboration with the Virtual Fly Brain project, have focused on capturing this information. Currently, 41% of the DAO comprises terms that are part of the nervous system, including around 2000 distinct neurons, over 200 lineage clones (including fruitless ones) as well as neuropils. Regarding the latter, we have already incorporated the recent paper by the BrainName group (Ito et al., 2014) that sets a standard nomenclature for the neuropil regions in the adult brain.
In the future, we will continue to review the existing DAO, working towards defining 100% of terms, and to keep the DAO up to date with newly published anatomical data.