Pregnancy-Associated Changes of IgG and Serum N-Glycosylation in Camel (Camelus dromedarius)

The dromedary camel (Camelus dromedarius) is an agriculturally important species of high economic value but of low reproductive efficiency. Serum and IgG N-glycosylation are affected by physiological and pathogenic changes and might therefore be a useful diagnostic tool in camel livestock management. This study presents the first comprehensive annotation of the N-glycome from dromedary camel serum as well as their single-domain and conventional antibodies and its subsequent application for camel pregnancy diagnostics. N-glycans were released by PNGaseF, labeled with 2-aminobenzamide (2-AB), and analyzed by hydrophilic interaction liquid chromatography with fluorescent detection (HILIC-UPLC-FLD), enzymatic sequencing and mass spectrometry (MS). The use of a high-throughput robotic platform for sample preparation allowed the rapid generation of glycomics data from pregnant (n = 8) and nonpregnant (n = 8) camels of the Majaheem and Wadha breed. IgG N-glycans dominate the glycan profile of camel serum and present a mixture of core-fucosylated and noncore-fucosylated N-glycans which can contain N-glycolylneuraminic and N-acetylneuraminic acid. Significant pregnancy-associated but breed-independent increases in galactosylation, core-fucosylation, sialylation, and decreases in serum O-acetylation were observed. The monitoring of IgG and serum N-glycosylation presents an attractive complementary test for camel pregnancy diagnostics and presents an interesting tool for biomarker discovery in camel health and breeding.