| Embryo production in vitro is a large and complex technique system, and it can't succeed without the key oocyte cultivation in vitro. At present the study of Wapiti (Cervus elaphus) embryo engineering technique is only on the start-up stage, so there are many blank fields nobody set food in. Our studies on oocytes ultrastructure, in which experimental materials came from Wapiti (Cervus elaphus), was just one of the blanks. Before collecting the oocytes by aspiration and deeply-cut the deer had been dealt with FSH for superovulation. The condition of wapiti maturation and fertilization in vitro was 38.5°C, 5% carbon dioxide and saturated humidity. It was studied by use of light microscope and transmission electron microscope, the shape, size and ultrastructure of wapiti oocytes and the organelles in them, which were selected from different developing stages.The results of this research are as followings:1.Under the light microscope we had observed that the diameter of mature oocyte became shorter than the immature one. The diameters of these two kinds of oocytes were 172.997±17.271μm and 161.311±5.721μm respectively.2.Under the transmission electron microscope we had figured out the diametric length of mitochondria, lipid droplets and vesicle in different kind of wapiti oocyte. The mitochondria longer and shorter diameters of immature oocyte were 0.60±0.11μm and 0.49±0.12μm, the mature one's were 0.77±0.13μm and 0.66±0.11μm, and the fertilized one's were 0.59±0.05μm and 0.46±0.05μm. The lipid droplets diameters of immature, mature and fertilized oocyte were 1.55±0.08μm, 1.02±0.46μm and 1.27±0.43μm. The vesicle longer and shorter diameters of immature oocyte were 0.87±0.35μm and 0.65±0.30μm, the mature one's were 1.30+0.45μm and 1.04±0.41μm, and the fertilized one's were 0.69±0.08μm and 0.60±0.09μm.3. Before the oocytes were cultivated in vitro, the cumulus cells surrounded them tightly, the long and thin microvilli were on their surface and deep in the zona pellucida, and there were a lot of organelles in the area of cortex and the center of the cells.4.After the oocytes were maturated in vitro, the link between cumulus cells and oocytes became loose, the microvilli lying on the oocytes surface turned short and thick, the cortical granules were distributed in layers in the cortex area, but the organelles were distributed wellin cytoplasm.5.After the oocytes were fertilized in vitro, the microvilli on their surface were erected, the first polar body had no nucleus, the second polar body had, and in cytoplasm of the oocytes there were abundant organelles that were mainly distributed in the center of the cells.6.The regular distributing pattern of the organelles was that with the wapiti oocyte maturation, Golgi complex, mitochondria, cortical granules and so on were more and more, and they did moving gradually from the center of cell to the cortical areas until they were distributed in all the cytoplasm at last.7. The sizes of all kinds of organelles in an oocyte were bigger and bigger with the oocyte's mature growth, but after the oocyte was fertilized they became smaller and smaller with the zygote's growth.All the results from this research can be used as a scientific reference to upbuild and perfect the wapiti oocyte in vitro cultivation system and improve the efficiency of wapiti oocyte maturation and fertilization in vitro. |
PDF Full Text Request