FIG. 1.—

Core carbon metabolic pathways believed to form the backbone of energy metabolism in microsporidia. Enzymes are in red and metabolites in black. All the enzymes shown are present in the genomes of Encephalitozoon cuniculi, Antonospora locustae, Nosema ceranae, and Octosporea bayeri, with the single exception of lactonase (in gray) which has not been identified. In contrast, only two enzymes in any of these pathways are present in Enterocytozoon bieneusi (shown in red on black).