Distribution of Gene Ontology categories of ESTs from shrimp. Frequency of GO classes for EST groups 1, 2, 3 (orange bars, pink bars, green bars) from 4 Penaeus species are shown in 3 organized categories (from top to bottom): biological processes (blue labels), cellular components (red labels), and molecular function (black labels). Within each category, the first level ontology classes are shown by (increasing) frequency of EST counts. Classification of GO are based on those assigned to best-matched fruit fly or nematode proteins by FlyBase or WormBase. The red arrow points to a class found exclusively in group 2 ESTs.