拟目乌贼卵子发生与卵巢发育

为了丰富拟目乌贼(Sepia lycidas)生物学资料, 为人工育苗与养殖提供理论依据, 采用解剖学和组织学的方法, 对水泥池养殖条件下拟目乌贼卵子发生和卵巢发育进行了研究。结果表明: 经过6个月水泥池养殖, 平均体重为256.34 g, 最大体重达到457.08 g, 个别发育成熟, 绝大部分未达性成熟。卵子发生不同步, 根据细胞形态、细胞大小、滤泡细胞形态和卵黄形成情况可分为卵原细胞阶段(卵原细胞期)、原生质生长阶段(无滤泡期、单层滤泡期和双层滤泡期)、间质生长阶段(滤泡内折早期、滤泡内折中期和滤泡内折晚期)和营养质生长阶段(卵黄发生早期、卵黄发生晚期和成熟期), 共4个阶段10个时期。卵巢发育根据外观形态、性腺指数变化和切面上各期细胞所占的比例, 可分为形成前期、形成期、小生长期、大生长期、成熟前期和成熟期6个时期。拟目乌贼繁殖周期为一年。       

隆线溞孤雌溞生殖系统的组织学

隆线孤雌的生殖系统由一对卵巢、一对输卵管和一对雌性生殖孔组成。卵巢长管状 ,管壁由结缔组织膜和单层上皮细胞构成 ,末端渐细为一短小的输卵管 ,输卵管末端为雌性生殖孔。卵子的发生是由生发区细胞向卵巢内增殖分化 ,不同成熟度的生殖细胞在管腔内排列成生殖带。根据卵母细胞细胞核的大小及卵黄的累积情况等 ,将卵子的发生划分为三个时期 :卵原细胞、卵母细胞和成熟卵子 ,其中卵母细胞的发生又可细分为三个时期 :前期、中期和后期。后期的卵母细胞含较多的卵黄颗粒 ,最后成为成熟卵子 ,排入孵育囊内形成夏卵。隆线孤雌的卵巢发育要经历五个幼龄期 ,不同的龄期 ,卵巢的形态结构不同。至第五幼龄 ,卵巢已基本发育成熟 ,准备排卵进入第一成龄     

粗糙沼虾卵巢发育的组织学

利用组织切片技术,对粗糙沼虾的卵子发生和卵巢发育周期进行了组织学研究。根据细胞的大小、细胞核和核仁的大小形态及卵黄积累等情况,将卵子发生划分为4个时期,卵原细胞、卵黄合成期的卵母细胞、成熟前期和成熟期。卵黄合成期的卵母细胞又可细划分为3个时期。粗糙沼虾卵巢发育具有一定的规律性。根据卵巢的大小和颜色及每种雌性生殖细胞在卵巢中所占的比例,将卵巢发育划分为7个时期。并通过卵巢发育规律的探讨,对粗糙沼虾的人工养殖提出了合理的建议。     

南美白对虾卵子发生的组织学

采用组织学方法研究了南美白对虾的卵子发生过程,根据卵细胞大小、核仁形态、卵黄粒的有无、皮质棒的出现以及卵母细胞与滤泡细胞的关系,将南美白对虾的卵子发生划分为卵原细胞、卵黄发生前的卵母细胞和卵黄发生的卵母细胞三个时期,并描述了各期卵细胞的形态特征。     

隆线潘孤雌溞生殖系统的组织学

隆线溞孤雌溞的生殖系统由一对卵巢、一对输卵管和一对雌性生殖孔组成。卵巢长管状,管壁由结缔组织膜和单层上皮细胞构成,末端渐细为一短小的输卵管,输卵管末端为雌性生殖孔。卵子的发生是由生发区细胞向卵巢内增殖分化,不同成熟度的生殖细胞在管腔内排列成生殖带。根据卵母细胞细胞核的大小及卵黄的累积情况等,将卵子的发生划分为三个时期：卵原细胞、卵母细胞和成熟卵子,其中卵母细胞的发生又可细分为三个时期：前期、中期和后期。后期的卵母细胞含较多的卵黄颗粒,最后成为成熟卵子,排入孵育囊内形成夏卵。隆线溞孤雌溞的卵巢发育要经历五个幼龄期,不同的龄期,卵巢的形态结构不同。至第五幼龄,卵巢已基本发育成熟,准备排卵进入第一成龄。     

棉铃虫卵巢形态与卵子发生过程观察

害虫发生高峰期、 发生量的准确预测和田间防治适期的确定与种群雌虫卵巢结构及卵子发生过程密切相关。为了明确棉铃虫Helicoverpa armigera卵巢结构及卵子发生过程, 本研究利用光学体视显微镜和透射电子显微镜, 对棉铃虫成虫卵巢管和卵子的超微结构进行了研究, 并确定了发育级别划分标准。结果表明: 根据卵巢的形状、 卵的产生过程、 卵黄沉积情况等将棉铃虫卵巢发育程度分为6个级别, 即发育初期(0级)、 卵黄沉积前期(Ⅰ级)、 卵黄沉积期(Ⅱ级)、 成熟待产期(Ⅲ级)、 产卵盛期(Ⅳ级)和产卵末期(Ⅴ级)。根据卵子发生过程中滋养细胞、 卵母细胞的变化, 将卵子发生期分为3个阶段： 卵黄发生前期、 卵黄发生期和卵黄成熟期。本研究首次对棉铃虫的卵子发生进行电子显微观察, 并完善了棉铃虫卵巢发育的分级标准, 为进一步研究棉铃虫的生殖发育机理提供了理论参考, 对田间棉铃虫种群发生期和发生量的预测预报也有重要的实践参考价值。     

刘氏蝎蛉卵巢管结构和卵子发生（英文）

卵巢管结构及卵子发生过程在探讨昆虫系统发育关系中有重要意义, 深入研究长翅目昆虫卵巢管结构及卵子发生可为确定其在全变态类昆虫中的系统发育地位提供依据。本文利用光学显微镜和扫描、透射电子显微镜技术研究了刘氏蝎蛉Panorpa liui Hua卵巢管超微结构及卵子发生过程。结果表明：蝎蛉卵巢由12根多滋式卵巢小管组成, 每个卵巢小管分为端丝、生殖区和生长区。根据滋养细胞、卵母细胞及滤泡细胞的变化, 卵子发生过程可分为5个阶段：卵黄发生前早期、卵黄发生前中期、卵黄发生前后期、卵黄发生期及卵壳形成期。在卵黄发生期, 滋养细胞为卵母细胞提供养分后逐渐消亡, 而此时的卵母细胞可通过滤泡之间的细胞间隙从血淋巴中获取营养。在卵壳形成期间, 3种不同类型的滤泡细胞参与形成不同区域的卵壳, 从而形成不同花饰的卵壳表面。据此推测, 与其他目的滋养细胞数目相比, 每个卵室中2次有丝分裂形成3个滋养细胞可能是比较原始的特征, 表明长翅目昆虫可能是全变态类群中近基部的分支。     

黄胫小车蝗卵子发生及卵母细胞凋亡的显微观察

对黄胫小车蝗(Oedaleus infernalis)卵子发生过程和卵母细胞凋亡进行显微观察。结果表明,黄胫小车蝗卵子发生可明显分为3个时期10个阶段,即卵黄发生前期、卵黄发生期和卵壳形成期。第1阶段,卵母细胞位于卵原区,经历减数第一次分裂;第2阶段,卵母细胞核内染色体解体成网状,滤泡细胞稀疏地排列在卵母细胞周围;第3阶段,滤泡细胞扁平状,在卵母细胞周围排成一层;第4阶段,滤泡细胞呈立方形排在卵母细胞周围;第5阶段,滤泡细胞呈长柱形排在卵母细胞周围,滤泡细胞之间、滤泡细胞与卵母细胞之间出现空隙;第6阶段,卵母细胞边缘开始出现卵黄颗粒;第7阶段,卵母细胞中沉积大量卵黄,胚泡破裂;第8阶段,滤泡细胞分泌卵黄膜包围卵黄物质;第9阶段,滤泡细胞分泌卵壳;第10阶段,卵壳分泌结束,卵子发育成熟。卵母细胞发育过程中的凋亡发生在卵黄发生前期,主要表现为滤泡细胞向卵母细胞内折叠,胞质呈团块状等特征。     

缠绕蚊蝎蛉雌性生殖系统构造及卵子发生

雌性生殖系统构造及卵子发生过程在探讨昆虫系统发育关系中具有重要意义。本文利用半薄切片法解剖观察了缠绕蚊蝎蛉Terrobittacus implicatus (HuangHua,2006)雌性生殖系统的构造及卵子发生过程。结果表明,缠绕蚊蝎蛉雌虫的卵巢由7根多滋式卵巢管组成,各个卵巢管的大小和长度不同。每个卵巢管可分为端丝、生殖区(原卵区)、生长区(卵黄区)和卵巢管柄4个部分。生长区由5到6个线形排列的卵室组成,每个卵室中有1个卵母细胞和3个滋养细胞。卵子发生可以分为3个时期,即卵黄发生前期、卵黄发生期、以及卵壳形成期。在卵子发生的整个过程中,卵母细胞、滋养细胞及滤泡细胞的形态均有明显变化。     

秀丽白虾卵母细胞不同发育阶段滤泡细胞的超微结构

用透射电镜技术观察了秀丽白虾(Exopalaemon modestus)不同发育阶段卵巢滤泡细胞的超微结构及其与卵母细胞的联系。随着卵母细胞的发育进程,滤泡细胞经历了发育和退化过程。在卵黄大量发生期,卵母细胞被多层滤泡细胞包绕,血窦伸入层间;滤泡细胞内含有丰富的内质网、高尔基体、线粒体、核糖体及原始卵黄颗粒。在卵子成熟期,滤泡细胞由内向外依次解体,血窦萎缩。这些形态变化支持滤泡细胞具有吸收血液营养、合成并向卵母细胞输送原始卵黄物质的功能的观点。与锯缘青蟹、长毛对虾和中华绒螯蟹的滤泡细胞的作用方式稍有不同。     

Oogenesis and oocytes

The morphological features of polychaete ovarian morphology and oogenesis are reviewed. Some basic information on ovarian structure and/or oogenesis is known for slightly more than half of recognized polychaete families although comprehensive studies of oogenesis have been conducted on 0.1 of described species. Relative to other major metazoan groups, ovarian morphology is highly variable in the Polychaeta. While some species appear to lack a defined ovary, most have paired organs that are segmentally repeated to varying degrees depending on the family. Ovaries vary widely in their location but are most frequently associated with the coelomic peritoneum, parapodial connective tissue, or elements of the circulatory system. The structural complexity of the ovary is correlated with the type of oogenesis expressed by the species. In some polychaetes, extraovarian oogenesis occurs in which previtellogenic oocytes are released into the coelom from a simple ovary where differentiation occurs in a solitary fashion or in association with nurse cells or follicle cells. In other species, intraovarian oogenesis occurs in which oocytes undergo vitellogenesis within the ovary, often in association with follicle cells that may provide nutrition. Vitellogenesis probably includes both autosynthetic and heterosynthetic processes; autosynthesis involves the manufacture of yolk bodies via the proteosynthetic organelles of the oocyte whereas heterosynthesis involves the extraovarian production of female-specific yolk proteins that are incorporated into the oocyte through a receptor-mediated process of endocytosis. Variation in the speed of egg production varies widely and appears to be correlated with the vitellogenic mechanism employed. Mature ova display a wide range of egg envelope morphologies that often show some intrafamilial similarities.     

中华蚱蜢卵子发生中花生凝集素受体的初步鉴定和发育表达

The distributions of PNA binding glycoconjugates in the plasma membrane of Acrida cinerea Thunberg germ cells were detected using biotin labeled PNA, for better understanding of the formation and changes of glycoconjugates during oogenesis. The ultrastructure of vitellogenesis also was observed by electron microscopy for detection of the origin and track of vitelline material. In the ovary, PNA receptors appeared in the oocyte cytoplasm of the second phases of oogenesis; positive granules gradually increased from the third phase to the fourth, and they exhibited a maximum expression before the vitellogennic stage in the cytoplasm of the oocyte. From the vitellogennic to chorionation stage, positive granules gradually declined. Binding sites on follicle cells were changed with their morphological variation in every stage of oogenesis. The vitelline of A. cinerea formed within the oocyte by degrees. The results suggest that PNA receptors and yolk materials are synthesized by the oocytc at an early period. With the development of the oocyte, some exogeous materials from two sources act as PNA receptors and others take part in vitelline synthesis. One is blood lymph that offers some useful materials to the oocyte directly through follicle cell gaps; the other are follicle cells that produce and transmit some materials to oocyte to support vitellogenesis. In addition, PNA receptors secreted by follicle cells participate in the formation of yolk membrane [ Acta Zoologica Sinica 5 l （5） ： 932 - 939, 2005 ].     

Oogenesis in the leech Glossiphonia heteroclita (Annelida, Hirudinea, Glossiphonidae). I. Ovary structure and previtellogenic growth of oocytes

Glossiphonia heteroclita has paired ovaries whose shape and dimensions change as oogenesis proceeds: during early previtellogenesis they are small and club-shaped, whereas during vitellogenesis they broaden and elongate considerably. During early oogenesis (previtellogenesis), each ovary is composed of an outer envelope (ovisac) that surrounds the ovary cavity and is filled with hemocoelomic fluid, in which a single and very convoluted ovary cord is bathed. The ovary cord consists of germline cells, including nurse cells and young oocytes surrounded by a layer of elongated follicle cells. Additionally, follicle cells with long cytoplasmic projections occur inside the ovary cord, where they separate germ cells from each other. The ovary cord contains thousands of nurse cells. Each nurse cell has one intercellular bridge, connecting it to a central anucleate cytoplasmic mass, the cytophore (rachis); it in turn is connected by one intercellular bridge with each growing oocyte. Numerous mitochondria, RER cisternae, ribosomes, and Golgi complexes are transported from the nurse cells, via the intercellular bridge and cytophore, to the growing oocytes. Oogenesis in G. heteroclita is synchronous with all oocytes in the ovary in the same stage of oogenesis. The youngest observed oocytes are slightly larger than nurse cells, and usually occupy the periphery of the ovary cord. As previtellogenesis proceeds, the oocytes gather a vast amount of cell organelles and become more voluminous. As a result, in late previtellogenesis the oocytes gradually protrude into the ovary cavity. Simultaneously with oocyte growth, the follicle cells differentiate into two subpopulations. The morphology of the follicle cells surrounding the nurse cells and penetrating the ovary cord does not change, whereas those enveloping the growing oocytes become more voluminous. Their plasma membrane invaginates deeply, forming numerous broad vesicles that eventually seem to form channels or conducts through which the hemocoelomic fluid can easily access the growing oocytes.     

鳗鲡繁殖生物学研究 Ⅲ.鳗鲡性腺发育组织学和细胞学研究

鳗鲡精巢发育可划分为6个时期,即精原细胞前增殖期,精原细胞后增殖期,精母细胞生长、成熟期,精子开始出现期,精子完全成熟期和精子退化吸收期。卵细胞的发育可划分为6个时相,即卵原细胞时相,卵母细胞单层滤泡时相,卵母细胞出现脂肪泡时相,卵母细胞卵黄充满时相,卵母细胞核极化时相和卵母细胞退化时相。以卵细胞发育6个时相在卵巢中组成的差异,也可把卵巢划分为相应的6个时期。对鳗鲡性腺发育的分期,卵黄积累方式,产卵类型等问题进行了讨论。       

Opposing effects of Notch-signaling in maintaining the proliferative state of follicle cells in the telotrophic ovary of the beetle Tribolium

ABSTRACT: INTRODUCTION: Establishment of distinct follicle cell fates at the early stages of Drosophila oogenesis is crucial for achieving proper morphology of individual egg chambers. In Drosophila oogenesis, Notch-signaling controls proliferation and differentiation of follicular cells, which eventually results in the polarization of the anterior-posterior axis of the oocyte. Here we analyzed the functions of Tribolium Notch-signaling factors during telotrophic oogenesis, which differs fundamentally from the polytrophic ovary of Drosophila. RESULTS: We found Notch-signaling to be required for maintaining the mitotic cycle of somatic follicle cells. Upon Delta RNAi, follicle cells enter endocycle prematurely, which affects egg-chamber formation and patterning. Interestingly, our results indicate that Delta RNAi phenotypes are not solely due to the premature termination of cell proliferation. Therefore, we monitored the terminal /stalk cell precursor lineage by molecular markers. We observed that upon Delta RNAi terminal and stalk cell populations were absent, suggesting that Notch-signaling is also required for the specification of follicle cell populations, including terminal and stalk precursor cells. CONCLUSIONS: We demonstrate that with respect to mitotic cycle/endocycle switch Notch-signaling in Tribolium and Drosophila has opposing effects. While in Drosophila a Delta-signal brings about the follicle cells to leave mitosis, Notch-signaling in Tribolium is necessary to retain telotrophic egg-chambers in an "immature" state. In most instances, Notch-signaling is involved in maintaining undifferentiated (or preventing specialized) cell fates. Hence, the role of Notch in Tribolium may reflect the ancestral function of Notch-signaling in insect oogenesis. The functions of Notch-signaling in patterning the follicle cell epithelium suggest that Tribolium oogenesis may - analogous to Drosophila - involve the stepwise determination of different follicle cell populations. Moreover, our results imply that Notch-signaling may contribute at least to some aspects of oocyte polarization and AP axis also in telotrophic oogenesis.     

Gap junctions in ovarian follicles of Drosophila melanogaster: inhibition and promotion of dye-coupling between oocyte and follicle cells

The analysis of chimeras has shown that communication between germ-line and soma cells plays an important role during Drosophila oogenesis. We have therefore investigated the intercellular exchange of the fluorescent tracer molecule, Lucifer yellow, pressure-injected into the oocyte of vitellogenic follicles of Drosophila. The dye reached the nurse cells via cytoplasmic bridges and entered, via gap junctions, the somatic follicle cells covering the oocyte. The percentage of follicles showing dye-coupling between oocyte and follicle cells was found to increase with the developmental stage up to stage 11, but depended also on the status of oogenesis, i.e., the stage-spectrum, in the respective ovary. During late stage 10B and stage 11, dye-coupling was restricted to the follicle cells covering the anterior pole of the oocyte. No dye-coupling was observed from stage 12 onwards. During prolonged incubation in vitro, the dye was found to move from the follicle cells back into the oocyte; this process was suppressable with dinitrophenol. Dyecoupling was inhibited when prolonged in vitro incubation preceded the dye-injection. Moreover, dye-coupling was inhibited with acidic pH, low [K⁺], high intracellular [Ca²⁺], octanol, dinitrophenol, and NaN₃, but not with retinoic acid, basic pH, or high extracellular [Ca²⁺]. Dyecoupling was stimulated with a juvenile hormone analogue and with 20-hydroxyecdysone. Thus, gap junctions between oocyte and follicle cells may play an important role in intercellular communication during oogenesis. We discuss the significance of our findings with regard to the electrophysiological properties of the follicles, and to the coordinated activities of the different cell types during follicle development and during the establishment of polarity in the follicle.