Abstract: Vitellogenin（Vg）is the precursor of vitellin,providing essential nutrients and energy for the developing embryo in many oviparous animals. As an important nutrient protein in eggs,Vg’s structure and modification are very conserved in different animals. The mature Vgs contain an N-terminal domain（Vitellogenin_N,VitN）,a middle-region domain of unknown function（DUF）,a von Willebrand factor type D（vWD）C-terminal domain,and a conserved polyserine tracks. During the vitellogenesis stage and under the induction of hermones,Vg is abundantly expressed in the liver of vertebrate animals or the fat body of insects. After modification and proteolytic cleavage,the Vg subunits are assembled in tissues,secreted into the hemolymph and taken up by oocytes via receptor-mediated endocytosis. In the ovaries,the Vg subunits are further processed into mature york proteins. In addition to the classic nutrient transport,Vg exerts multiple non-nutritinal function during its transport. When Vg interacts with the viral capsid protein,the virus might be transported into the insect ovary via the uptake of Vg by developing oocytes. In hemolymph,Vg is able to play roles in immune responses,either as a pattern recognition molecule to recognize bacteria,or as an opsonin to enhance macrophage phagocytosis. Moreover,Vg has also been reported to be expressed by non-females and works in behavior regulation of insects. Here,we will review the main research progresses in Vg’s systhesis,processing,modification and its non-nutritional functions,including the functions in females and non-females. In order to provide the following Vg function.

Key words: vitellogenin, non-nutritional function, non-female expression, immunity