Figure 1. Presence of trehalose synthetic pathway in the apicomplexans as determined from available genome sequences.

Within the pathway, UDP-glucose/galatose pyrophosphorylase (UGGPase) is present in almost all apicomplexans with the exception for piroplasmids (e.g., Theileria and Babesia) [marked as Api(-Piro)], while trehalose-6P synthase and trehalose phosphatase (TPase) are fused as a bifunctional protein that is present in all apicomplexans with the exception for Plasmodium species [marked as Api(-Plasmo)]. Trehalase may only be present in the intestinal coccidia (Eimeria). For comparison, the mannitol cycle present only in the intestinal coccidia (represented by Eimeria tenella) is also illustrated.