Uptake and incorporation of sialic acid by the tick Ixodes ricinus

We describe the detection of sialylated N-linked glycans in partially fed Ixodes ricinus tick females using matrix-assisted laser desorption/ionization time-of-flight/time-of-flight mass spectrometry. Sialylated glycans were detected in salivary glands as well as in tick guts and we propose the host origin of these structures. In addition, we mapped the transport of sialylated structures from the blood meal through the gut to the salivary glands using electron microscopy. Specific localization of sialylated glycans to basement membranes of salivary glands was observed. Finally, the influence of the sample preparation methods for electron microscopy on ultrastructure and immunogold labeling was evaluated.

Highlights► Sialylated N-glycans were identified in fed females Ixodes ricinus. ► Composition of the sialylated N-glycans was confirmed by MS/MS analyses. ► N-glycolylneuraminic acid was immunolocalized in gut and salivary glands. ► We propose the host origin of sialylated N-glycans.