雌核生殖

Using the methods of classical shape size measuring and chromosome analysis, we studied the morphological characters and Karyotype of Cobitis sinensis in Xiangjiang River. We also investigated the evolution line and Karyotype polymorphism of the C . sinensis by the methods of cytological classification and cytocatalytic. Our results suggest that the formation of chromosome polymorphism was concerned with heterologous hybridization and some of C . sinensis may perpetuate in a clonal manner by natural gynogenesis.

本文以湘江流域的中华花鳅为研究对象，运用经典的形态测量观察方法、染色体制片技术对中华花鳅的形态生态特征、染色体组型进行了初步研究：运用细胞分类和进化方法对中华花鳅的核型演化和核型多态现象的形成进行了分析，提出：其核型多态的形成牵涉到鳅科鱼类的异源杂交，某些中华花鳅可能是行雌核发育生殖的。

Parthenogenesis in which the egg is activated by sperm ,but without fusion of the egg and sperm nuclei.

雌核生殖一种单性生殖，精子激活卵子，但是卵子和精子核没有融合

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.

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。

The effect of food concentration on characteristics in life history of Brachionus urceus, such as the duration of principal development stage, net reproductive rate and mixis rate in all the offspring, was studied by the method of clonal culture.

方法］采用单个体培养法，研究了不同浓度的蛋白核小球藻对壶状臂尾轮虫主要发育阶段历时、净生殖率以及全部后代的混交雌体百分率等生活史特征的影响。

Generally, two hybridization events have happened in the generation of gynogenetic crucian carp: the first one occurred about 6, 000 years ago when maternal ancestor of C. a. gibelio hybridized with males of C. a. auratus (ancestor of C. a. colored variety) and a diploid hybrid was produced; the second one happened over 10, 000 years ago, when the diploid hybrid was backcrossed with one of its parental population, by which the current triploid gynogenetic crucian carp emerged.

初步推断出东北雌核生殖银鲫是通过鲫鱼种群间的两次杂交产生的，第一次杂交是母本的银鲫同源种群与父本的彩鲫同源种群杂交，形成二倍体杂种；第二次杂交是二倍体杂种与两个祖先鲫鱼种群之一回交，形成了今天的三倍体杂种银鲫。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失