Lipid bodies of O. umbellatum ovary epidermis are surrounded by a network of microtubules and assembled in lipotubuloids i.e. cytoplasm domains containing ribosomes, ER cisternae and vesicles as well as some mitochondria, microbodies, Golgi structures and autolytic vacuoles. Lipid bodies in statu nascendi grow from 0.04 up to about 0.1 µm. In maturity they are about 0.1-0.4 µm in diameter and maintain this dimension during epidermis development, accompanied by lipotubuloid enlargement resulting in the higher number of lipid bodies. Using the immunogold technique with anti-diacylglycerol acyltransferase 2 and anti-lipase antibodies it was shown that mature lipid bodies were labeled with gold grains near a phospholipid monolayer. Autoradiography with 3H-palmitic acid demonstrated that lipid body surface is the site of this precursor incorporation into lipids. Selective labeling of lipotubuloid lipid bodies with silver grains observed after 2-h incubation of the ovary disappeared after 6-h postincubation in the non-radioactive medium. It can be suggested that the size of mature lipid bodies does not change because of the dynamic balance between synthesis and degradation of lipids inside them. It was shown that lipotubuloid growth dynamics was closely correlated with the growth of ovary epidermis cells. Lipids of lipotubuloids are probably building block of cuticle.
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