1. In the present work, the origin and cytochemistry of both the types of yolk (fatty and compound) in the oogenesis of
Locusta migratoria are discussed.
2. The fatty yolk globules (
L3 bodies), consisting of triglycerides only, are derived from the Golgi bodies (
L1 bodies), consisting of phospholipids only, through an intermediate stage, the duplex Golgi bodies (
L2 bodies) which contain phospholipids in their cortices and triglycerides in their medullae. In this process the thick cortex of duplex Golgi bodies becomes greatly attenuated.
3. The compound yolk globules have their origin from the fine circumnuclear carbohydrate granules of the early oocyte which arrange themselves at the cortical ooplasm in the late stages of oogenesis, where they grow and form the compound yolk globules.
4. The protein moiety of the compound yolk is formed under the influence of nucleolar RNA which plays an important role in protein synthesis.
5. Cytochemically, the compound yolk consists of carbohydrates (1:2 glycol groups) and acidic proteins; it is devoid of mucopolysaccharides and glycogens.
6. The mitochondria, throughout oogenesis, remain in the form of small granules and do not take part in yolk synthesis.
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