Vitellogenin

Definition

A large phospholipoglycoprotein synthesized in response to juvenile hormone or ecdysteroids and secreted into the hemolymph by the fat body of insects (or hepatopancreas of crustaceans), then sequestered by developing oocytes via receptor-mediated endocytosis and processed into yolk proteins. It serves as the primary nutrient reserve for the embryo and is a standard molecular marker for reproductive status, endocrine disruption, and vitellogenesis in arthropod physiology and ecotoxicology.

Etymology

From Latin vitellus (yolk) + -genin (producing), referring to its role in yolk formation.

Example

In the mosquito Aedes aegypti, a blood meal triggers ecdysteroid release from the ovaries, stimulating massive vitellogenin synthesis by the fat body within 24 hours; this hemolymph vitellogenin is then endocytosed by primary follicles and cleaved into vitellin, the major yolk protein.

Synonyms

• Vg (gene/protein abbreviation)
• VIT (abbreviation in some literature)

Related Terms

• Vitellogenesis
• Vitellin
• Fat body
• Juvenile hormone
• ecdysteroid
• Oogenesis
• yolk protein
• endocrine disruption
• Hemolymph

Usage Notes

In insects, vitellogenin is female-specific under normal conditions, making it a sensitive biomarker for environmental estrogens or endocrine-active compounds that induce synthesis in males. The term distinguishes the circulating precursor (vitellogenin) from the stored yolk form (vitellin), though both derive from the same gene product. Concentrations are often quantified by ELISA or Western blot in studies of reproductive physiology, toxicology, and social insect behavior (e.g., vitellogenin titer correlates with worker fertility in honey bees).