We present the design of an object-oriented database system for reverse genetics applications. Such a database will encapsulate not only the data in the genetic and physical maps, but also the methods used to create the maps as well as methods to link them to other databases, such as GenBank, PIR, and MedLine. The purpose of this database is to provide the fungal genetics community with an electronic tool for identifying the biochemical function of any DNA fragment in the database--electronic reverse genetics. Such a tool for reverse genetics will enable researchers to identify the biochemical functions associated with genes encoding proteins in fungal development pathways, purine metabolism, the heat shock response, and molecular chromosome mechanics and evolution. Our initial goal is to apply the database for the genome mapping of the filamentous fungi, Aspergillus nidulans and Neurospora crassa, at the University of Georgia and the University of Leeds in England.