Glycosphingolipid glycan diversity. The arthroseries glycosphingolipids (GSLs) are built by extension from a mactosylceramide core (Manβ1-4Glcβ-ceramide). Neutral arthroseries glycans are frequently modified by the addition of phosphoethanolamine (EthNP; orange ovals) on N-acetylglucosamine residues, forming a zwitterionic structure. Acidic charge is imparted by the addition of glucuronic acid to nonreducing terminal galactose residues on neutral or zwitterionic cores. (Light gray box) Species-specific core diversity is evident in the alternative extension of the arthroseries triaosylceramide by galactose rather than N-acetylgalactosamine in Drosophila. (Dark gray boxes) Other arthropods supplement their arthroseries GSLs by distinctive modifications. Moth cells (Sf9) extend the mactosylceramide core with galactose and then N-acetylgalactosamine. In two dipteran species, the larvae of the greenbottle fly (Lucilia caesar) and the pupae of the blowfly (Calliphora vicina), but not in embryos of Drosophila, the arthroseries tetraosylceramide is extended with galactose, capped with glucuronic acid, and modified with EthNP.