Synthesis of a high-density lipoprotein in the developing blue crab (Callinectes sapidus)

An important lipoprotein in the hemolymph of crustaceans is LpI. It transports lipid to peripheral tissues and also has a role in crustacean immune recognition. We employed a monoclonal antibody specific for the LpI peptide to demonstrate by ELISA, western blot and immunohistochemistry the appearance of LpI during development of Callinectes sapidus, the blue crab. LpI was first found in stage 5 embryos and appeared to be synthesized by lateral basophilic cuboidal cells that demonstrated cytoplasmic immunoreactivity for LpI at their interface with the yolk mass. The embryonic cuboidal cells bore a strong cytologic resemblance to the hepatopancreas cells of later stages (zoea, megalopae, adults), which were also immunoreactive for LpI.