GO Tutorial: Build Your Own Ontology II

Exercise I Take Home Messages

Exercise II

Making Relationships

Download the example file and load it into DAG-Edit.

The example file contains a set of GO terms from the cellular component ontology.

GO uses two relationships:

Add is-a and part-of relationships to the terms to create a mini ontology.

To change the relationship type, click on the term and select Change relationship type to from the Edit menu and select the appropriate type. You can give a term multiple parents by shift-dragging one term on top of another term. Remember that any relationships you make must be true for the parent term and all of its ancestors.

For this exercise, assume that part-of means that the child is always (necessarily) part of the parent.

Can you see any extra relationships that could be added if part-of meant the child is sometimes but not always a part of the parent?