Phylogenetic Tree

Vitellogenin

Vitellogenin (VTG or less popularly known as VG) (from Latin vitellus, yolk, and genero, I produce) is a precursor of egg yolk that transports protein and some lipid from the liver through the blood to the growing oocytes where it becomes part of the yolk. Vitellogenin is the precursor of the lipoproteins and phosphoproteins that make up most of the protein content of yolk. It belongs to a family of several lipid transport proteins.

--From Wikipedia