摘要
为了解小鼠胚着床前细胞中线粒体的分布和超微结构的变化规律，观察了２细胞胚、４细胞胚、８细胞胚、桑椹胚、早期囊胚和晚期囊胚。２细胞期和桑椹胚期，线粒体绕胞核密集，在挤紧的８细胞胚中，线粒体在细胞接触面处的胞质边缘密集。囊胚期，滋养层细胞的线粒体在胞核周围较宽的区域中分布。囊胚经罗丹明１２３染色后，在荧光显微镜下显现为颗粒状。挤紧的８细胞胚，经秋水仙素（１０ｍｇ／Ｌ）处理后，线粒体在胞质中变为弥散分布。电镜下可见从受精卵至４细胞期，线粒体呈球形、无嵴、中央有低电子密度区。８细胞期，线粒体呈球形或圆形，内部出现嵴。桑椹期至囊胚期，线粒体变长，呈杆状。
The ultrastructure and distribution patterns of mitochondria in blastomeres are successively changing during preimplantation development of mouse embryo, and present specific features at various stages. In the development of early preimplantation embryo there are three major translocations of mitochondria in cytoplasm of blastomere. The first translocation is between 1 cell and 2 cell stages, which results in perinuclear concentration of mitochondria.The second is at 8 cell stage, during compaction of embryo the distribution patterns of mitochondria are from even dispersion to aggregate in the margin area of cytoplasm along the surfaces of opposite blastomeres. The third is at morula stage, in which mitochondria reaggregate in a broader region around nucleus. At blastula stage the mitochondria of trophoblast still reveal a perinuclear arrangement in a broader area of cytoplasm, and they are viewed as clear granules under fluorescence microscope. According to the phenomena of mitochondrial dispersion throughout the blastomeres cytoplasm of compacted 8 cell embryo which was exposed to colchicine, we suggest that the microtubules probably play a key role in maintenance of the distribution patterns of mitochondria in blastomeres. Ultrastructures indicate that at different stages of embryo, the appearance of mitochondria has different features. In the 1 to 4 cell embryos mitochondra are spheroidal in shape with a low electron density area in the center, and there are no cristae in it. In the blastomeres of 8 cell embryos the mitochondrion has a ovoid shape and contains a few cristae.The majority of the mitochondria of morula and blastula are elongated in structures with transverse cristae within them.Thus, the transmission electron microscopic and fluorescence microscopic observations demonstrated that during development of preimplantation embryos the mitochondria develop from a simple spherical appearance to more mature form which would be convenient to provide increasing amounts of ATP for further developmental eve
出处
《解剖学报》
CAS
CSCD
北大核心
1998年第3期303-306,I017,共5页
Acta Anatomica Sinica
基金
山东省科学技术委员会资助
关键词
线粒体
着床前胚
小鼠
胚胎发育
超微结构
Mitochondrion
Preimplantation embryo
Mouse △School of Life Science, Shandong University, Ji'nan 250100,China
