Vitellogenesis

Yolk proteins, such as Lipovitellin and Phosvitin, provides maturing oocytes with the metabolic energy required for development.

Once Vitellogenins are released into the blood stream where they are then transported to the growing oocyte where they lead to yolk protein production.

Yolk is a lipoprotein composed of proteins, phospholipids and neutral fats along with a small amount of glycogen.

Through circulation it is transported to the follicle cells that surround the maturing ovum, and is deposited in the form of yolk platelets and granules in the ooplasm.

The mitochondria and Golgi complex are said to bring about the conversion of the soluble form of yolk into insoluble granules or platelets.