Abstract:

【Objective】 By comparing the mitochondrial ultrastructure among the normal goat embryos, cloned intraspecies goat embryos (reconstructed by goat enucleated oocytes and boer goat ear skin fibroblast) and cloned bovine-goat interspecies embryos (reconstructed by bovine enucleated oocytes and boer goat ear skin fibroblast), the cause of poor development of cloned interspecies embryos was found at subcellsular level. The result would give a new thinking from different angles to study cloned interspecies embryos. 【Method】 The mitochondrial ultrastructure of normal goat embryos, cloned intraspecies goat embryos and cloned bovine-goat interspecies embryos were detected by transmission electron microscope at pronucleus, 2-cell, 4-cell, 8-cell and morulae stages. 【Result】 The mitochondria of nomal embryos and cloned intraspecies embryos were cap-like and developed from high electron density and less cristaes to low electron density and rich cristaes with the development of embryo. However, a kind of abnormal-shaped mitochondria of multi-filiation was appeared in the cloned bovine-goat interspecies embryos. These mitochondria could form the normal and rich cristaes, which means they become matured. 【Conclusion】 These results showed that the crosstalking between nuclear and cytoplasm could not be regulated effectively, which means that the bovine ooplasm can not reprogamme the goat somatic cell nuclear, and conversely, the goat somatic cell nuclear can not instruct the mitochondria in bovine oocyte efficiently.

Key words: bovine')">bovine, goat, interspecies clon, ultrastructure, mitochondria