Method for improving developmental capacity of sheep mature oocytes after vitrification

Abstract

The invention relates to a method for improving the developmental capacity of sheep mature oocytes after vitrification refrigeration, belonging to the technical field of biology. The method comprises the steps of micro-injection fertilization of sheep mature oocytes and activation of fertilized eggs, wherein the activation of the fertilized eggs adopts a direct current pulse-chemical activation-direct current pulse mode, and experiments prove that the embryonic developmental capacity of the vitrified sheep mature oocytes subject to is greatly improved after the vitrified sheep mature oocytes is subject to intracytoplasmic sperm injection and is activated by the activation method of the invention. Compared with the conventional external fertilization method, the cleavage rate and the blastocyst rate are respectively increased to 13.7% and 6.8%. At the same time, by comparing the chromosome ploidy of embryos subject to different treatments, the result indicates that the proportion of normal-ploidy embryos (71.5%) obtained by the ECE method is apparently higher than that (45.4%) obtained by the common chemical activation method and no obvious difference exists compared with the external fertilization groups.

Description

technical field [0001] The invention relates to the field of animal embryo biotechnology, in particular to a method for improving the development of sheep oocytes, which the application calls Electric-Chemical-Electric, ECE method. Background technique [0002] Oocyte cryopreservation is not only of great significance for the preservation of endangered species, but also provides a large number of available materials for basic research. In recent years, the preservation of oocytes by vitrification has achieved better results than the traditional slow freezing method. Many reports have preserved oocytes from different animals using vitrification, and healthy offspring have also been obtained in some reports. However, the success rate of vitrification of sheep oocytes is still low at present. Compared with fresh oocytes, the developmental ability of oocytes after vitrification is very low. It has been reported that the vitrification process can cause multiple damages to anima...

AI Technical Summary

Problems solved by technology

These changes seriously hinder the normal fertilization process, so that the sperm cannot enter the oocyte for fertilization. The use of microinjection can increase the rate of sperm entering the oocyte, but the development ability of the oocyte after vitrification is very low, and additional treatment is required. The normal development of oocytes can only be initiated by stimulation. At present, chemical activation methods are mostly used for the activation of oocytes. However, after chemical activation, it is easy to activate parthenogenetic embryos and cannot form normal diploid embryos.

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