Vitellogenin (Vg), the precursor of egg-yolk proteins in all oviparous organisms, shares a similar domain structure combination. In most cases, Vg contains the Vitellogenin_N domain, the domain of unknown function (DUF) 1943, and the von Willebrand factor type D domain (VWD), which are present in different forms of Vg from both vertebrates and invertebrates… (More)