Figure 1.
Scheme of the process followed to retrieve GO terms associated to Affymetrix probe sets. Cylinders are databases, boxes are entries, diamonds and circles are attached properties. Plain lines are direct links, whereas arrows indicate a fuzzy relation of inclusion in the direction of the arrow. See text for details of those databases. (a) Sources of GO terms. Source 0: NetAffx. Source 1: links from NetAffx to other databases annotated with GO terms. Sources 2 and 3 use inference from properties associated to linked entries. Source 2 consists of GO terms derived from SwissProt keywords (KW2GO mapping) and MeSH terms (categories A, C, D, and G) from MEDLINE (MeSH2GO mapping). Source 3 consists of GO terms derived from sources 0, 1, and 2, by a mapping between GO terms (GO2GO mapping). (b) General schema for the definition of a mapping. A fuzzy mapping is computed by analysis of co-occurrences of the values of a property "p" attached to a database d1 entry (left) and another property "q" attached to database dn entry (right) via any number of intermediate databases. (c) Mappings used in this work: KW2GO, MeSH2GO, and GO2GO. See Methods for details.