Oogenesis in the common Japanese conger Conger myriaster   总被引：1，自引：0，他引：1  

TOMOKO  UTOH  NORIYUKI  HORIE  AKIHIRO  OKAMURA  YOSHIAKI  YAMADA  SATORU  TANAKA  NAOMI  MIKAWA  ATSUSHI  AKAZAWA  HIDEO P  OKA 《Fisheries Science》2003,69(1):181-188

ABSTRACT:    We investigated the process and characteristics of oogenesis in the common Japanese conger Conger myriaster . Young fish caught in November 1996 were reared for use in this experiment. Fish were sampled monthly from December 1997 to August 1998. Some were injected with human chorionic gonadotropin to stimulate ovarian maturation from May to August 1998. Oocytes from the chromatin nucleolus stage to the secondary yolk globule stage were obtained from non-hormone-treated fish; those of more advanced stages were obtained from hormone-treated ones. We divided oocyte development into eight stages from the chromatin nucleolus stage to the maturation stage. The yolk vesicle stage was not separated because yolk vesicles began to appear just after appearance of yolk globules. Oocyte, oil droplet, yolk globule and nucleus diameters all increased concomitant with oocyte development. Oil droplet and yolk globule diameters increased remarkably at the maturation stage. However, zona radiata thickness peaked at the secondary yolk globule stage, decreasing gradually thereafter. Increased gonadosomatic index was related to oocyte development as found in European and Japanese eels receiving hormone treatment to mature. The present study is the first report describing oogenesis characteristics in congrid eels. It indicates that oogenesis is almost identical to that of other anguillid eels.  相似文献   

Co‐expression and regulation of ovarian vitellogenins in the Pacific oyster Crassostrea gigas     

Raúl Llera‐Herrera  Celia Vázquez‐Boucard  Alejandra García‐Gasca  Arnaud Huvet 《Aquaculture Research》2014,45(3):448-459

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Oocyte recruitment and fecundity type in fishes: Refining terms to reflect underlying processes and drivers          下载免费PDF全文

Kostas Ganias  Susan Lowerre‐Barbieri 《Fish and Fisheries》2018,19(3):562-572

Only with new technology and the ability to simulate systems are we beginning to understand fish reproductive processes at the individual scale over time. Traditionally, oocyte recruitment and fecundity type in fishes have been based on a “snapshot” approach, that is a histological micrograph and/or oocyte size frequency distribution of a spawning capable female has been assumed to indicate oocyte recruitment processes over time. This has important implications as the asynchronous and group‐synchronous oocyte recruitment patterns are associated with indeterminate and determinate fecundity types, respectively, and thus affect estimates of reproductive potential and spawning biomass (if using egg production methods). However, a historic review of these terms revealed that they are not applied consistently, with the same oocyte recruitment pattern often assigned to both of these by different scientists. The intent of this study is to develop a conceptual model of oocyte recruitment processes over time, key drivers, and resulting “snapshots” to refine oocyte recruitment terms, definitions, and the methods needed to identify them.  相似文献   

粘虫卵子发生的组织化学研究——I、DNA、RNA、蛋白卵黄的动态     

孙少轩  牟吉元 《山东农业大学学报(自然科学版)》1986,(3)

用组织化学方法研究了粘虫卵子发生各时期中卵巢内核酸、卵黄蛋白的动态。滋养细胞与卵细胞的核均为多倍体,其DNA含量随生长而增加。卵核迁至卵的边缘后不久,DNA即解聚而表现为Feulgen阴性。滋养细胞的核及发育早期的卵细胞核内都有核仁排出。观察四个滋养细胞,其活动期间仅以RNA供应給卵,未见其他成分经细胞间桥进入卵内。蛋白、磷脂与解聚状态的DNA均在滋养细胞最后被卵吸收时方始入卵。蛋白卵黄粒为中性粘多糖,其前体来自卵包上皮,与蛋白卵黄的主要区别在于它为PAS阴性,且不含半胱氨酸或甲硫氨酸,故認为蛋白卵黄一部份原料由卵包细胞供应,另一部份由卵直接以胞飲方式自血淋巴中吸收。  相似文献   

野蚕黑卵蜂雌性内生殖器官的结构及其发育     

刘永华阎雄飞  叶恭银李鲜花 《昆虫天敌》2007,29(1):1-5

报道了野蚕黑卵蜂成虫雌性内生殖器官的结构及其发育的系统观察结果。雌性成虫内生殖器官包括一对卵巢、两条侧输卵管、中输卵管、受精囊和附腺。成虫期卵巢生长速度随日龄是先增大后减小,但卵子随日龄是增大后并不下降,而且卵子成熟量一直保持较高水平,显示该蜂具有较强的生殖力。成虫期内其它生殖器官一般随日龄的增长而增大,达到一定程度后基本保持稳定。  相似文献   

The effects of dietary supplements of polyunsaturated fatty acid on pearl oyster,Pinctada margaritifera L., gonad composition and reproductive output     

Fariborz Ehteshami  Annie Christianus  Hossein Rameshi  Sharr Azni Harmin  Che Roos Saad 《Aquaculture Research》2011,42(4):613-622

Black‐lip pearl oyster, Pinctada margaritifera broodstock was collected from the wild. Egg production, hatching rate and larval development were compared between oysters induced to spawn within 2 days after collection in the wild (T1), oysters fed a pure microalgae diet during 24 days before spawning (T2) and oysters fed the same microalgal diet in which 10% of the algae were replaced with 2 μm polyunsaturated fatty acid (PUFA)‐rich microspheres (T3). Administration of lipid microspheres resulted in larger sized eggs, a higher percentage of D‐larvae and larger sized 48‐h‐old larvae (P<0.05). The total and neutral lipid contents of the gonad increased after oysters were fed with microalgae only or with supplementary diet. The major neutral and polar fractions of saturated fatty acid (SFA) were 16C and 18C fatty acids, and not influenced by the diet (P>0.05). The gonads of oysters fed supplementary PUFA contained more docosahexaenoic acid (DHA) and less monounsaturated fatty acids. Higher level of DHA in gonads of T3 was associated with oogenesis and embryogenesis success. The n‐3/n‐6 ratio in the neutral lipid fraction provides a good indication of the spawning condition and predicting egg size and hatching rate.  相似文献   

中华鳖dazl基因克隆及在生殖细胞中的表达     

唐舟凯  张飘逸  储张杰  朱新平  李伟  吴栩灵  徐红艳 《水产学报》2019,43(2):400-409

为探索龟鳖类生殖细胞的发育分化机制,实验通过特异性引物克隆了中华鳖dazl基因的cDNA片段,长1 007 bp,其中包括5′端非编码区197 bp,3′端非编码区33 bp,开放阅读框777 bp,编码258个氨基酸。氨基酸序列比对显示其与西部锦龟Dazl同源性最高,达96%;与小鼠Dazl同源性达75%。荧光定量PCR分析结果显示,中华鳖dazl mRNA主要在精巢和卵巢中表达,在体细胞组织中仅检测到微量表达。冰冻切片原位杂交结果显示,中华鳖dazl mRNA在生殖细胞中特异表达,且在不同时期的生殖细胞中呈动态表达模式。在精巢中,中华鳖dazl mRNA在初级和次级精母细胞中表达最强,在精原干细胞中表达水平次之,在精子细胞中未检测到信号;在卵巢中,中华鳖dazl mRNA信号在初级卵母细胞胞质中均匀分布且在最早期的初级卵母细胞中信号最强,随着卵母细胞的增大,信号逐渐聚集并逐渐减弱。研究表明,dazl基因可能对中华鳖两性生殖细胞的发生具有重要的调控作用。  相似文献   

外源性促性腺激素诱导日本鳗鲡卵子发生和卵巢发育成熟的机制     

宋海霞  方琼珊  翁幼竹  王涵生  方永强 《水产学报》2010,34(7):999-1010

用兔抗促黄体素生成素受体(LHR)或称绒毛膜促性腺激素受体(CGR)、雌激素受体(ER)和孕激素受体(PR)的抗体对LHR,ER和PR进行免疫组织化学定位。目的在于揭示外源性促性腺激素(鲤鱼脑垂体提取物,CPE和人绒毛膜促性腺激素,hCG)诱发日本鳗鲡卵子发生和卵母细胞成熟的内分泌机制。结果表明,注射激素前后卵巢发育和卵子发生出现了十分显著的变化。卵巢组织学切片观察显示激素处理前鳗鲡卵巢发育处于卵黄发生早期,卵母细胞平均直径(220±0.01)μm。第一次注射这两种激素后10d,实验组卵母细胞中卵黄核分散在核的周围,核仁数量显著增加,多达18～20个左右,而对照组8～10个。第3和4次激素处理后,卵母细胞发育进入卵黄发生早-中期至中期,卵黄颗粒数量增加。第6和7次激素处理后,卵母细胞进入卵黄发生中后期到成熟期,卵母细胞胞质中充满卵黄颗粒,胞径和核径增加,分别为(570±1.39)μm和(128±1.19)μm,而对照组没有变化。其次,免疫组织化学染色结果显示LHR、ER和PR均定位在鳗鲡卵巢中卵母细胞胞质、核膜、核质、卵被膜和体细胞上。这里值得指出的是,从第3次和第4次激素处理后,这三种受体的定位各有特点,L...  相似文献   

Effects of accelerated photoperiod regimes on the reproductive cycle of the female rainbow trout: II Seasonal variations of plasma gonadotropins (GTH I and GTH II) levels correlated with ovarian follicle growth and egg size     

E. Bon  B. Breton  M.S. Govoroun  F. Le Menn 《Fish physiology and biochemistry》1999,20(2):143-154

Female rainbow trout were exposed over their second reproductive cycle to a simulated natural photoperiod (control group) and to two accelerated photoperiod regimes (S9 and S6 groups). Early spawning was achieved in both accelerated groups, coupled, however, with a reduction of mean egg size. To investigate this reduction of egg size, circulating levels of GTHs and two indices of ovarian growth (gonadosomatic index and follicle diameter) were regularly measured in association with histological studies of structural changes in ovarian follicles. Regardless of the photoperiod regime, the seasonal profile of plasma GTH I levels appeared to be multiphasic. The successive transient elevations in GTH I levels appeared to be connected with the initiation of ovarian growth and vitellogenesis and also, with the synchronization of the late stages of maturation and ovulation. In contrast, the seasonal profile of plasma GTH II levels was monophasic, with a single peak at ovulation, confirming that GTH II is not associated with ovarian growth but promotes gamete maturation and release. Our results demonstrate that the reduction of egg size cannot be due to a deficient secretion of GTH I in plasma, since GTH I levels were much higher during vitellogenesis in both accelerated groups, but rather to an alteration of ovarian follicle growth during the late stages of vitellogenesis. Finally, the early and middle stages of ovarian growth appeared to be photosensitive periods, whereas the late stages were less so, and appeared to be controlled rather by an endogenous biological clock synchronized by the photoperiod.  相似文献   

鲫鱼卵子发生──Ⅱ一些细胞器的变化和放射带的形成   总被引：3，自引：0，他引：3  

严云勤  郑晓民 《东北农业大学学报》1995,26(3):273-279

在卵原细胞和早期的Ⅰ期卵母细胞中，没有内质网和线粒体．在Ⅱ期和Ⅲ期的卵母细胞中，线粒体和内质网逐渐增多，线粒体常被一层粗面内质网包绕着．在成熟卵子中，线粒体和内质网多分散在卵皮质部分．线粒体有多种形态结构．高尔基复合体经历了从少到多，再到少的变化过程．另外，鲫鱼的卵母细胞中还有丰富的环形片层．放射带是由卵母细胞和滤泡细胞伸出突起并向其中分泌物质而形成．  相似文献