Genetic metabolic complementation establishes a requirement for GDP-fucose in .

To survive in its sand fly vector, the trypanosomatid protozoan parasite first attaches to the midgut to avoid excretion, but eventually it must detach for transmission by the next bite. In strain Friedlin, this is controlled by modifications of the stage-specific adhesin lipophosphoglycan (LPG). During differentiation to infective metacyclics, d-arabinopyranose (d-Ara) caps the LPG side-chain galactose residues, blocking interaction with the midgut lectin PpGalec, thereby leading to parasite detachment and transmission.