Table 1. Evidence of trehalose synthetic pathways in Cryptosporidium and some other apicomplexans and alveolates as shown by the presence of genes encoding UDP-galactose/glucose pyrophosphorylase (UGGPase), Class II trehalose-6P synthase-trehalose phosphatase (T6PS-TPase) in their genomes.
| Trehalose metabolism | Mannitol cycle | |||||||
| Group | Genus | UGPase | UGGPase | T6PS-TPase | Trehalase | M1PDH | M1Pase | MannDH |
| (No. species with available genomes) | 2.7.7.9 | 2.7.7.64 | 2.4.1.15 3.1.3.12 | 3.2.1.28 | 1.1.1.17 | 3.1.3.22 | 1.1.1.255 | |
| Apicomplexan | Cryptosporidium (3) | - | + | + | - | - | - | - |
| Plasmodium (7) | - | + | - | - | - | - | - | |
| Theileria (2) | - | - | + | - | - | - | - | |
| Babesia (1) | - | - | + | - | - | - | - | |
| Toxoplasma (1) | - | + | + | - | - | - | - | |
| Eimeria (1) | - | + | + | + | + | + | + | |
| Dinoflagellate | Perkinsus (1) | - | + | + | + | - | - | - |
| Ciliate | Paramecium (1) | - | + | + | + | - | - | - |
| Tetrahymera (2) | - | + | + | - | - | - | - | |
| Mammal | Homo (1) | + | - | - | + | - | - | - |
Notes: Genes involved in the anti-stress related mannitol cycle were also minded for comparison. Plus and minus symbols indicate the presence and absence of specified genes in various apicomplexans, a dinoflagellate and two ciliates at genus level. Humans are listed to represent mammalian hosts for apicomplexan parasites.