Vitellogenin

Part of speech: noun

Definitions

1. A phospholipoglycoprotein synthesized in the liver of egg-laying animals that is transported to the ovary and forms the main protein of yolk
2. A protein made in the liver of females that is carried into developing eggs, where it is processed into the nutrient-rich yolk proteins
3. The precursor protein, produced by the liver under estrogen control, that supplies the building blocks for yolk in developing oocytes

Etymology: Vitellogenin is a compound name built from two Latin-derived parts: "vitellus," meaning yolk (a diminutive of "vitulus," calf, which itself gave the root sense of something young and fleshy), and the Greek-derived suffix "-gen," meaning producing or giving rise to. Together they describe a substance that generates yolk. The name is a modern scientific coinage, formed from classical roots in the same way as many biochemical terms of the twentieth century, so no ancient writer ever used it. The "-gen" element is the one most readers will recognise from words like "oxygen" and "antigen," where it means something that produces or forms the thing named. Biochemists chose it because the protein's role is to build the yolk that feeds a developing embryo, which is exactly what the name says. The "vitello-" stem is the same root that appears in the older English adjective "vitelline," used of yolk.