卵原细胞

Oogonium develops into early oocyte in the ovary, and then the oocyte leaves the ovary for the coelomic fluid in the form of single cell or cell mass followed by the rapid separation of the group of oocytes into individual ones. Oocyte enters into the nephridium after its maturation. The rupture of germinal vesicle marks the oocyte maturation. Oocyte in the coelom does not have follicle membrane and vitelline membrane is formed and developed by the oocyte itself. Smaller oocyte (0μm in diameter) is round, and larger ones (≥60μm in diameter) is ovate. The short and long diameters of a morphologically mature oocyte are about 115—120μm and 140—145μm respectively, and the vitelline membrane is 7—9μm thick.

卵原细胞在卵巢中发育至早期卵母细胞时期单个或成团脱离卵巢入体腔液中，卵母细胞团细胞很快分离为单个细胞；卵母细胞在体腔液中发育成熟后进入肾管；生发泡破裂是卵母细胞成熟的标志；体腔中卵母细胞无滤泡膜，卵黄膜的形成与发育靠卵母细胞本身；卵径小于60μm的卵母细胞呈圆形，卵径大于60μm 的卵母细胞为卵圆形，形态上成熟的卵母细胞短径约115—120μm、长径约140—145μm、卵黄膜厚7—9μm。

At the small growth stage, three kinds of the sex steroid receptors usually were localized in the cytoplasm or nuclear membrane of oogonia and early primary oocyte, and localized in the cytoplasm and nucleoplasm of oocytes at the large growth stage and mature stage.

在小生长期，3种受体通常定位在卵原细胞和早期初级卵母细胞的胞质或核膜；在大生长期和成熟期，则定位在胞质和核质。

The results show that, with the maturity of the gonad, the undifferentiated germ cell divided and differentiated to smaller oogonium or spermatogonia, and the oogonium or spermatogonia transformed to oocyte and sperm undergoing a series of maturation process.

摘 要 通过观察栉江珧的未分化生殖细胞，精原细胞和卵原细胞，精母细胞和卵母细胞，精子和卵子的形态结构与分布状况及核仁在卵成熟过程中的变化，对栉江珧生殖细胞发生及成熟过程的有关问题进行了探讨。

According to the size and shape of oocyte, the morphology of nucleolus, the growth of yolk and the structure of follicle, oogenesis of H. d. supertexta can be divided into three stages as follows: oogonium, previtellogenic oocyte and vitellogenic oocyte. The ovary wall is composed of tunica adventitia and germinal epithelium which will produce oogonia and follicle cells. The follicle is the structure unit of ovary.

根据卵细胞的大小、形状，核仁的形态，卵黄颗粒的积累情况，滤泡的结构等，将九孔鲍卵子的发生分为卵原细胞、卵黄发生前的卵母细胞和卵黄发生期的卵母细胞3个时期；卵巢壁由外膜及内生殖上皮构成，生殖上皮分化产生卵原细胞和滤泡细胞；卵巢的结构单位是滤泡。

The oogenesis of P. esculenta can be divided into the following phases in morphological characteristics of oogonium and oocyte development: the proliferative phase of oogonium (0μm in diameter), the initial growth phase of oocyte (10—20μm in diameter), the grand growth phase-Ⅰof oocyte (20—60μm in diameter), the grand growth phase-II of oocyte (60μm×70μm to 120μm×145μm in size), the mature phase of oocyte, and the declining phase, showing a dynamic changes in oogenesis of P. esculenta .

以卵原细胞与卵母细胞发育的形态学特征为依据，将可口革囊星虫的卵子发生过程划分为：卵原细胞增殖期(卵径0μm)、卵母细胞小生长期(卵径10—20μm)、卵母细胞大生长期Ⅰ(卵径20—60μm)、卵母细胞大生长期Ⅱ[大小为(60μm×70μm)—(120μm×145μm)]、卵母细胞成熟期及退化期6 个阶段，反映了可口革囊星虫卵子发生过程的动态变化。

The females incubated at 33 , their ovarium has powerful cortex, the germinal epithlium produce oocyte, its medulla degenerate into ovarian cavity. During sexual differentiation, mitochondria and smooth endoplasmic reticulum in cells of ovary increase in quantity, they disintegrate after sexual differentiation. There are a lot of big grana in cells of ovary before sexual differentiation, in the course of sexual differentiation the quantity of the big grana decrease, while small grana increase and peakafter sexual differentiation. The males incubation at 26 , cortices of their testes degenerate into a thin albuginea. Medulla are formed by testicular cords in which scatter spermatogonium.

33℃下孵化的小龟卵巢皮质发达，由原始生殖细胞产生卵原细胞，髓质退化成为卵巢腔，分化时卵巢细胞的超微结构显示线粒体和内质网的数量大大增加，它们在分化结束后解体，分化前细胞内有较多的大颗粒，在分化中大颗粒减少，小颗粒增多，在分化后小颗粒达到最多。26℃下孵化的小龟精巢皮质退化成为一层薄的白膜，髓质有许多睾丸管构成，管腔内有散落排列的精原细胞。

The results indicated: 1 .There is obvious difference between the gonads of precocious and unprecocious fish: in female, the ovaries of unprecocious fish stay in 141 stage, and are mainly consisted of oogonias and early oocytes; the ovaries of precocious fish have developed into IIIAV stage, most of the oocytes are in the large growth stage.

性早熟与未早熟大黄鱼性腺的发育有显著不同：未早熟鱼卵巢停留在Ⅰ～Ⅱ期，卵巢内主要由卵原细胞和早期卵母细胞所组成；性早熟大黄鱼卵巢已发育至Ⅲ～Ⅳ，卵巢内大多数卵母细胞处于大生长期中期或后期。

The results were as follows: nanos 1 mRNA uniformly dispersed throughout the cytoplasm of oocytes at all stages. Strong expression of nanos1 mRNA was observed in oogonia and stageⅠ、Ⅱ oocytes, but the signal became weaker in later stage oocytes.

结果表明：在斑马鱼卵子发生中，nanos1 mRNA均匀分布于卵原细胞和各时期卵母细胞的胞质中；在卵原细胞和Ⅰ、Ⅱ期卵母细胞中，nanos1 mRNA的杂交信号十分强烈，而较晚期卵母细胞中信号明显减弱。

The results showed that immunopositive substance existed in the ovary and testis of different stages. At the early developmental stage of ovary, the cytoplasm and nucleolar membrane of oogonia and early primary oocyte showed immunopositive reaction with strong or medium intensity to 17 b -estradiol, testosterone and progesterone antibodies.

在卵巢发育早期，卵原细胞和卵母细胞的胞质和核仁膜对雌二醇、睾酮和孕酮抗体显示强或中等强度免疫阳性反应；在大生长期和成熟期，卵母细胞胞质和核仁膜对睾酮和孕酮抗体的免疫阳性反应明显减弱，而对雌二醇则显著增强。

Also, the intensity of immuno-positive reactions to them enhance with the development of the gonads.

免疫组织化学法也显示卵原细胞、卵母细胞、精原细胞、精母细胞和精子细胞存在睾酮和17β-雌二醇的免疫阳性物质，而且睾酮和17β-雌二醇的免疫反应强度也是随着性腺发育成熟而增强。

It has been put forward that there exists single Ball point and double Ball points on the symmetrical connecting-rod curves of equilateral mechanisms.

从鲍尔点的形成原理出发，分析对称连杆曲线上鲍尔点的产生条件，提出等边机构的对称连杆曲线上有单鲍尔点和双鲍尔点。

The factory affiliated to the Group primarily manufactures multiple-purpose pincers, baking kits, knives, scissors, kitchenware, gardening tools and beauty care kits as well as other hardware tools, the annual production value of which reaches US$ 30 million dollars.

集团所属工厂主要生产多用钳、烤具、刀具、剪刀、厨具、花园工具、美容套等五金产品，年生产总值3000万美元，产品价廉物美、选料上乘、质量保证，深受国内外客户的青睐