哺乳动物卵子发生、激活与发育

近年来，应用于研究哺乳动物卵子和胚胎新的实验方法已有重大发展，为深入研究哺乳动物胚胎学提供了前所未有的重要手段。这些技术已用于原核和核的移植以至导入克隆基因，改变卵和胚台的遗传结构，用于实验重组着床前胚胎研究发育问题。近期的重大进展有如：用体细胞克隆的绵羊，父源和母源基因组在个体发育中的作用和第一与第二极体发育的全能性等，对这些过程的深入了解将为应用于家畜和人类提供发展遗传和生殖潜力的基础，本研究将论述哺乳动物卵子发生和胚胎发生的最新研究进展，包括：减数分列的启动。MⅡ期卵母细胞的激活，孤雌胚、雌核胚、雄核胚和重组胚的发育以及第一与第二极体染色体的遗传和生殖潜力。

Oogenesis,Activation and Development in Mammals

The experimental approaches applicable to the study of mammalian eggs and embryos have advanced in recent years to provide unprecedented opportunities for understanding mammalian embryology.Among these significant advances has been the ability to alter the genetic constitution of eggs by pronuclear and nuclear transfer as well as by the introduction of specific cloned genes into eggs and embryos.These techniques can be used in conjunction with the experimental reconstruction of preimplantation embryos to investigate more precisely a number of aspects of mammalian embryology.Recently,some intriguing aspects of development have been uncovered, such as the cloned sheep with somatic cell, role of paternal and maternal genomes in embryogenesis and the developmental totipotency of the first and the second polar body and so on.An understanding of this process will provide the basis for developing genetic and reproductive strategies that can be applied to domestic animals and to humans.The main research achievements on oogenesis and embryogenesis in mammals are described in this review,including the resumption of meiotic division;activation of MⅡ oocyte;development of parthenogenetic,gynogenetic,androgenetic and reconstituted embryos;and the genetic and reproductive potentials of chromosomes within the first and the second polar body.