藏北3种裸鲤同工酶的电泳分析及物种分化的探讨

对藏北高原３种裸鲤的乳酸脱氢酶（ＬＤＨ）、苹果酸脱氢酶（ＭＤＨ）和脂酶（ＥＳＴ）进行电泳分析的结果表明,３种裸鲤酶谱均表现出种间的差别,而且在同一种群个体之间也存在着明显的分化,但无性别差异。３种裸鲤被检测的３种同工酶均有沉默基因表达的现象,重复基因ＬＤＨ－Ａ^2、ＬＤＨ－Ｂ^2、s-MDH-A^2和m-MDH-B^2也在部分个体中表达。遗传距离分析表明,色林错裸鲤（Ｇ.selincuoensis)与错鄂裸鲤（Ｇ．cuoensis)之间较之于与纳木错裸鲤（Ｇ．namensis)有更近的亲缘关系。与其他四倍体鱼类相比,裸鲤鱼类同工酶在重复基因和沉默基因上都有较高的表达频率,这种情况说明裸鲤鱼类目前可能还外于多倍化后进化的早期过程并早于胭脂鱼类所处的相应时期,这与裂腹鱼类起源较晚以及青藏高原业已存在的恶劣环境条件直接相关。     

青海湖裸鲤性腺发育的组织学研究

采用石蜡组织切片法,对青海湖裸鲤的性腺发育进行组织学研究,系统地描述了各期卵巢和精巢的形态结构、特征及变化。结果表明:(1)青海湖裸鲤性腺的发育可分为六个时期,卵母细胞从第3时相发育到第4时相基本同步。第Ⅳ期末卵巢,第4时相卵母细胞的卵径大小比较整齐,卵径平均值为2.3mm,第4时相卵母细胞占切面上卵数的85%以上,占切片面积的96%以上,第2、3时相卵母细胞已很少;(2)产后卵巢的组织结构逐步由第Ⅵ期回复到第Ⅱ期,再由第Ⅱ期到第Ⅲ期向第Ⅳ期过渡;(3)性成熟个体有68.12%的雌鱼和83.9%的雄鱼以第Ⅳ期性腺越冬,另有21.01%的雌鱼和10.7%的雄鱼以第Ⅲ期性腺越冬,还有10.87%的雌鱼和5.4%的雄鱼以第Ⅱ期性腺越冬。根据青海湖裸鲤各季节性腺发育情况,作者认为青海湖裸鲤已达到性成熟的个体并不是每年都参与繁殖活动,存在生殖间断性。这反映了青海湖裸鲤的繁殖习性对高原寒冷多变气候的适应性。还对卵黄核和核仁在卵黄形成中的作用以及青海湖裸鲤的产卵类型和生殖间断性进行了讨论。     

短盖巨脂鲤卵巢发育组织学研究

通过对短盖巨脂鲤各个生长时期卵巢组织学研究以及成熟卵超微结构观察,获得短盖巨脂鲤生长发育过程中卵巢发育规律;同时对卵母细胞核仁排出物与核质关系及在卵黄形成中的作用等问题作了初步探讨;并根据卵巢的卵母细胞组成确定了其产卵类型。     

西藏南部的裸鲤属(Gymnocypris)鱼类

作者等1961年5—10月在中国科学院综合考察委员会的领导下,在西藏南部地区的江孜、日喀则两专区的部分水域中进行了鱼类采集,并于1962年在北京进行了鱼类的种类鉴定及资料整理。本文仅报告该地区的裸鲤属(Gymnocypris)鱼类,共9种。其中新种和新亚种共5个:高体裸鲤(新种)Gymnocypris molicorporus sp.nov.;秉氏裸鲤(新种)Gymnocypris pingi sp.nov.;驼背裸鲤(新种)Gymnocypris gibberis sp.nov.;朱氏裸鲤(新种)Gymnocypris chui sp.nov.;宽口秉氏裸鲤(新亚种)Gymnocypris pingi orisolatus     

埃塞俄比亚塔纳湖鲤科鱼类体内亚美尼亚许氏绦虫Khawia armeniaca (Cholodkovsky, 1915) Shulman, 1958 (绦虫纲: 鲤蠢目) 的形态鉴定

在埃塞俄比亚境内塔纳湖中发现了1种寄生于鲤科鱼类: 间魮(Labeobarbus intermedius)和Labeobarbus tsanensis体内的许氏绦虫, 经形态学鉴定其为亚美尼亚许氏绦虫Khawia armeniaca (Cholodkovsky, 1915)(绦虫纲: 鲤蠢目)。该绦虫鉴别特征为头节呈半球状, 边缘光滑, 无皱褶; 睾丸分布区域从虫体中部至阴茎囊之前; 卵巢前卵黄腺分布于虫体中后部至阴茎囊前部区域, 少数排列在阴茎囊之后; 子宫起始于阴茎囊后方弯曲环绕直至卵巢后部区域, 有少许卵黄腺排列在子宫和卵巢的两侧。此外, K. armeniaca卵巢呈滤泡状或蝴蝶状, 雌雄生殖孔分离但彼此距离很近, 开口于体表并形成同一生殖腔, 且雄性生殖孔位于雌性生殖孔前方。卵巢后卵黄腺数目少于100个, 分布于虫体末端, 卵黄腺距离卵巢后翼较远, 部分样品内卵黄腺接近卵巢后翼。     

花斑裸鲤胚胎/仔鱼型血红蛋白基因家族成员鉴定与时序表达研究

为了探讨花斑裸鲤(Gymnocypris eckloni)血红蛋白时序转换 利用花斑裸鲤全基因组数据鉴定胚胎/仔鱼型血红蛋白基因家族成员, 并通过整胚原位杂交方法, 检测花斑裸鲤胚胎/仔鱼型血红蛋白基因在胚胎发育不同阶段的表达及定位。结果表明, 花斑裸鲤基因组中共鉴定到5个胚胎/仔鱼型血红蛋白基因, 分别为hbae1、hbae4、hbae5、hbbe1和hbbe3, 与斑马鱼(Danio rerio)相比, 花斑裸鲤基因组缺少hbae3和 hbbe2 基因, 暗示第四轮全基因组复制事件后所经历的小规模基因删除事件在花斑裸鲤特异性血红蛋白基因形成中发挥了重要作用。整胚原位杂交结果显示, hbae1基因在胚胎发育的120h至432h内持续表达, hbbe1基因在96h开始表达持续至432h, hbbe3基因杂交信号出现在胚胎发育120h至384h内, 在胚胎发育全过程中未能观察到hbae4和hbae5基因的杂交信号。杂交信号主要位于胚胎正中轴、后部侧向中胚层、背主动脉腹侧区、尾部造血区及卵黄。正义探针作为阴性对照, 在胚胎发育阶段均无任何杂交信号。花斑裸鲤具有与其他鱼类不同的胚胎/仔鱼型血红蛋白基因家族成员及血红蛋白转换表达特征; hbae1、hbbe1和hbbe3基因在花斑裸鲤早期胚胎发育过程中发挥重要作用, 而hbae4和hbae5基因的生物学功能可能有所弱化。     

青海湖裸鲤类胰岛素生长因子IGF-Ⅱ的原核表达

青海湖裸鲤(Gymnocypris przewalskii)俗称湟鱼,属鲤科裂腹鱼亚科裸鲤属,是我国最大内陆咸水湖青海湖中唯一的经济鱼类,其生长极其缓慢,平均每生长到500g需要近10年[1]。青海湖裸鲤具有明显的生殖洄游,每年     

青海湖裸鲤CYP17a2基因的克隆及表达分析

CYP17a2基因是细胞色素CYP17(cytochrome P450,CYP)超家族成员之一,在卵巢发育过程中,可以与CYP17a1共同作用控制卵子的发育和成熟。研究和掌握青海湖裸鲤(Gymnocypris przewalskii)卵巢发育的基本规律,可为该鱼种的人工增殖放流及其资源保护和恢复提供技术支撑。本研究采用普通PCR和RACE方法克隆得到了青海湖裸鲤CYP17a2基因全长c DNA序列,并分析了其生物信息学意义,通过实时荧光定量PCR确定了CYP17a2基因在青海湖雌性裸鲤各组织中的表达分布特征。该基因的c DNA序列全长为1 871 bp,共编码390个氨基酸,所编码的氨基酸序列与斑马鱼和鲤鱼的同源性最高,分别为69%和64%。该基因在卵巢、卵巢膜、脑、肌肉、肝胰脏中均有表达,以在卵巢中表达量最高(p0.01)。本研究结果将为进一步开展CYP17a2基因在青海湖裸鲤卵巢发育的分子调节机理的研究中提供基础数据。     

青海湖裸鲤生活史类型的研究

用模糊聚类法定量研究了青海湖裸鲤的生活史类型,以平衡产量模式进行了验证,并用世代生物量法探讨了其合理捕捞强度与捕捞年龄.结果表明：青海湖裸鲤属比较典型的k-选择类型鱼类;青海湖裸鲤平衡产量曲线与达氏鳇的平衡产量曲线非常相似;青海湖裸鲤的临界年龄为15.67龄,整个世代生物量在11～16龄达到最大;建议对青海湖裸鲤进行捕捞的最小捕捞年龄为12龄,捕捞强度不超过0.1.     

色林错裸鲤的生长

对藏北高原色林错湖泊中色林错裸鲤（Gymnocypris selincuoensis)的生长方程、生长拐点以及生长指标等生长特征进行了分析。结果表明von Bertalanffy生长方程、Gompertz方程和三次多项式方程都可以反映色林错裸鲤的生长过程,但Gompertz方程能够很好地描述12龄之前的生长特征,而von Bertalanffy生长方程更适合描述18龄以后的生长特征。这种情况反映了色林错裸鲤具有洄游性鱼类更换生活环境的生活史特征。雄性体长的von Bertalanffy生长方程为：Lt=484.1906[1-e^-0.06839(t-0.06028)],雄性为Lt=485.3285[1-e^-0.0710(t-0.5679)]。体长和体重关系为W＝0.00023L^-5.5303(♂）和W＝0.00046L^2.4072(♀）。生长拐点为12.9龄（♀）和14．2龄（♂）。与其它裂腹鱼类相比,色林错裸鲤的生长过程尤为缓慢,这与其生存的环境条件更为恶劣直接相关。     

Fine Structure of the Ovarian Development in the Orb-web Spider, Nephila clavata

ABSTRACT Fine structural changes of the ovary and cellular composition of oocyte with respect to ovarian development in the orb-web spider, Nephila clavata were examined by scanning and transmission electron microscopy. Unlike the other arthropods, the ovary of this spider has only two kinds of cells-follicle cells and oocytes. During the ovarian maturation, each oocyte bulges into the body cavity and attaches to surface of the elongated ovarian epithelium through its peculiar short stalk attachments. In the cytoplasm of the developing oocyte two main types of yolk granules, electron-dense proteid yolk and electron-lucent lipid yolk granules, are compactly aggregated with numerous glycogen particles. The cytoplasm of the developing oocyte contains a lot of ribosomes, poorly developed rough endoplasmic reticulum, mitochondria and lipid droplets. These cell organelles, however, gradually degenerate by the later stage of vitellogenesis. During the active vitellogenesis stage, the proteid yolk is very rapidly formed and the oocyte increases in size. However, the micropinocytosis invagination or pinocytotic vesicles can scarcely be recognized, although the microvilli can be found in some space between the oocyte and ovarian epithelium. During the vitellogenesis, the lipid droplets in the cytoplasm of oocytes increase in number, and become abundant in the peripheral cytoplasm close to the stalks. On completion of the yolk formation the vitelline membrane, which is composed of an inner homogeneous electron-lucent component and an outer layer of electron-dense component is formed around the oocyte.     

Formation of primordial yolk granules in the avian oocyte

Summary Electron and light microscopical investigations of early oocytes (between 1.0 mm and 5.0 mm in diameter) from the ovary of 28–30 week-old chickens, suggested the formation of primordial yolk granules from cytoplasmic vesicles. These vesicles formed an aggregation which was observed to be surrounded by membranes, giving the aggregate a multivesicular body-like appearance. At a later stage the vesicles inside the membrane disintegrated and the multivesicular bodies acquired the appearance of primordial yolk granules. The contribution of other structures to the formation of yolk granules is discussed.For constructive criticism I am very grateful to Dr. Hadar Emanuelsson, Institute of Zoophysiology, Lund. The excellent technical assistance of Miss Inger Antonsson and Mrs. Annagreta Petersen is gratefully acknowledgedThis work was supported by Kungliga Fysiografiska Sällskapet, Lund     

Fine structure of the developing oocytes in adultArgas (Persicargas) arboreus (Ixodoidea: Argasidae)

The structure of the developing oocytes in the ovary of unfed and fed femaleArgas (Persicargas) arboreus is described as seen by scanning (SEM) and transmission (TEM) electron microscopy. The unfed female ovary contains small oocytes protruding onto the surface and its epithelium consists of interstitial cells, oogonia and young oocytes. Feeding initiates oocyte growth through the previtellogenic and vitellogenic phases of development. These phases can be observed by SEM in the same ovary.The surface of isolated, growing oocytes is covered by microvilli which closely contact the basal lamina investing the ovarian epithelium and contains a shallow, circular area with cytoplasmic projections and a deep pit, or micropyle, at the epithelium side. In more advanced oocytes the shell is deposited between microvilli and later completely covers the surface.Transmission EM of growing oocytes in the previtellogenic phase reveals nuclear and nucleolar activity in the emission of dense granules passing into the cytoplasm and the formation of surface microvilli. The cell cytoplasm is rich in free ribosomes and polysomes and contains several dictyosomes associated with dense vesicles and mitochondria which undergo morphogenic changes as growth proceeds. Membrane-limited multivesiculate bodies, probably originating from modified mitochondria, dictyosomes and ribosomal aggregates, are also observed. Rough endoplasmic reticulum is in the form of annulate lamellae. During vitellogenesis, proteinaceous yolk bodies are formed by both endogenous and exogenous sources. The former is involved in the formation of multivesicular bodies which become primary yolk bodies, whereas the latter process involves internalization from the haemolymph through micropinocytosis in pits, vesicles and reservoirs. These fuse with the primary yolk bodies forming large yolk spheres. Glycogen and lipid inclusions are found in the cytoplasm between the yolk spheres.     

凡纳滨对虾卵母细胞卵黄发生的超微结构

利用电镜研究凡纳滨对虾卵母细胞卵黄发生的全过程。结果表明 :凡纳滨对虾卵黄的发生是双源性的。卵黄发生早、中期是内源性卵黄大量合成的阶段 ,卵黄发生中、后期则以外源性卵黄的合成为主。内源性卵黄主要由内质网、线粒体、核糖体、溶酶体、高尔基器等多种胞器活跃参与形成。其中数量众多的囊泡状粗面内质网是形成内源性卵黄粒的最主要的细胞器 ;部分线粒体参与卵黄粒的合成并自身最终演变为卵黄粒 ;丰富的游离核糖体合成了大量致密的蛋白质颗粒并在卵质中直接聚集融合成无膜的卵黄粒 ;溶酶体通过吞噬、消化内含物来形成卵黄粒和脂滴 ,且方式多样 ;高尔基器不直接参与形成卵黄粒。外源性卵黄主要通过卵质膜的微吞饮活动从卵周隙或卵泡细胞中摄取外源物质来形成     

Oogenesis in the leech Glossiphonia heteroclita (Annelida, Hirudinea, Glossiphoniidae) II. Vitellogenesis, follicle cell structure and egg shell formation

By the end of previtellogenesis, the oocytes of Glossiphonia heteroclita gradually protrude into the ovary cavity. As a result they lose contact with the ovary cord (which begins to degenerate) and float freely within the hemocoelomic fluid. The oocyte's ooplasm is rich in numerous well-developed Golgi complexes showing high secretory activity, normal and transforming mitochondria, cisternae of rER and vast amounts of ribosomes. The transforming mitochondria become small lipid droplets as vitellogenesis progresses. The oolemma forms microvilli, numerous coated pits and vesicles occur at the base of the microvilli, and the first yolk spheres appear in the peripheral ooplasm. A mixed mechanism of vitellogenesis is suggested. The eggs are covered by a thin vitelline envelope with microvilli projecting through it. The envelope is formed by the oocyte. The vitelline envelope is produced by exocytosis of vesicles containing two kinds of material, one of which is electron-dense and seems not to participate in envelope formation. The cortical ooplasm of fully grown oocytes contains many cytoskeletal elements (F-actin) and numerous membrane-bound vesicles filled with stratified content. Those vesicles probably are cortical granules. The follicle cells surrounding growing oocytes have the following features: (1) they do not lie on a basal lamina; (2) their plasma membrane folds deeply, forming invaginations which eventually seem to form channels throughout their cytoplasm; (3) the plasma membrane facing the ovary lumen is lined with a layer of dense material; and (4) the plasma membrane facing the oocyte forms thin projections which intermingle with the oocyte microvilli. In late oogenesis, the follicle cells detach from the oocytes and degenerate in the ovary lumen.     

Chicken oocyte growth: receptor-mediated yolk deposition

During the rapid final stage of growth, chicken oocytes take up massive amounts of plasma components and convert them to yolk. The oocyte expresses a receptor that binds both major yolk lipoprotein precursors, vitellogenin (VTG) and very low density lipoprotein (VLDL). In the present study, in vivo transport tracing methodology, isolation of coated vesicles, ligand- and immuno-blotting, and ultrastructural immunocytochemistry were used for the analysis of receptor-mediated yolk formation. The VTG/VLDL receptor was identified in coated profiles in the oocyte periphery, in isolated coated vesicles, and within vesicular compartments both outside and inside membrane-bounded yolk storage organelles (yolk spheres). VLDL particles colocalized with the receptor, as demonstrated by ultrastructural visualization of VLDL-gold following intravenous administration, as well as by immunocytochemical analysis with antibodies to VLDL. Lipoprotein particles were shown to reach the oocyte surface by passage across the basement membrane, which possibly plays an active and selective role in yolk precursor accessibility to the oocyte surface, and through gaps between the follicular granulosa cells. Following delivery of ligands from the plasma membrane into yolk spheres, proteolytic processing of VTG and VLDL by cathepsin D appears to correlate with segregation of receptors and ligands which enter disparate sub-compartments within the yolk spheres. In small, quiescent oocytes, the VTG/VLDL receptor was localized to the central portion of the cell. At onset of the rapid growth phase, it appears that this pre-existing pool of receptors redistributes to the peripheral region, thereby initiating yolk formation. Such a redistribution mechanism would obliterate the need for de novo synthesis of receptors when the oocyte's energy expenditure is to be utilized for plasma membrane synthesis, establishment and maintenance of intracellular topography and yolk formation, and preparation for ovulation.     

Ultrastructural investigations of the ovary and oogenesis in the pycnogonids Cilunculus armatus and Ammothella biunguiculata (Pycnogonida, Ammotheidae)

Abstract. Ovarian ultrastructure and oogenesis in two pycnogonid species, Cilunculus armatus and Ammothella biunguiculata , were investigated. The ovary is morphologically and functionally divided into trunk and pedal parts. The former represents the germarium and contains very young germ cells in a pachytene or postpachytene phase, whereas the latter houses developing previtellogenic and vitellogenic oocytes and represents the vitellarium. Intercellular bridges were occasionally found between young (trunk) germ cells. This indicates that in pycnogonids, as in other animal groups, at the onset of oogenesis clusters of germ cells are generated. As nurse cells are absent in the ovaries of investigated species, the clusters must secondarily split into individual oocytes. In the vitellarium, the oocytes are located outside the ovary. Each oocyte is connected to the ovarian tissue by a stalk composed of several somatic cells. The stalk cells directly associated with the oocyte are equipped with irregular projections that reach the oocyte plasma membrane. This observation suggests that the stalk cells may play a nutritive role. The ooplasm of vitellogenic oocytes comprises mitochondria, free ribosomes, stacks of annulate lamellae, active Golgi complexes, and vesicles derived from these complexes. Within the latter, numerous electron-dense bodies are present. We suggest that these bodies contribute to yolk formation.     

Some aspects of the reproductive biology of perch Perca fluviatilis L. A histological description of the reproductive cycle

Histological changes in the perch ovary during development are described and related to changes in gonad weight and to a macroscopic scale of maturity stages after Kesteven (1960). A single organ formed by the fusion of two primordial ovaries, a central internal oviduct, and an extremely thick chorion surrounding oocytes are characteristic features of the perch ovary. Resting oocytes can be differentiated from developing oocytes which are larger and possess a granulosa layer which permits formation of the chorion and yolk acquisition. In the maturing ovary, oocyte diameter increases rapidly and the chorion, which possesses four layers, the tunica propria, two middle zones forming a fine network, and the zona radiata, also expands. The spent ovary is disorganized with follicles and tunica wall contracted, and a number of residual oocytes may be apparent. There was no evidence of pre-ovulatory degeneration although autolysis of a small number of residual oocytes was observed. The gonadosomatic index was highest for males in September and at a maximum in females immediately prior to spawning. After spawning the index fell rapidly with lowest values recorded in June and July. Variations in the gonadosomatic index are related to developmental stages in females.     

Yolk formation in an annelid (Ophryotrocha puerilis, polychaeta)

The polychaete Ophryotrocha does not show a distinct breeding season. Egg masses are produced throughout the year (continuous breeder sensu Olive and Clark, 1978). A female specimen may contain up to three different generations of oocytes with oocyte growth and maturation in each batch being well synchronized. Oogenesis takes about 18 days from proliferation of the oogonia to mature eggs. In each segment pairs of sister cells interconnected by cytoplasmic bridges are located in outpocketings of the ventral mesentery which form the gonad wall. Presumptive oocytes and nurse cells are not easily distinguished at that time. Vitellogenesis is initiated while both oocytes and nurse cells are still in the ovary. Mitochondria, multivesicular bodies (transformed mitochondria ?), dense bodies, preformed yolk bodies of smaller size and lipid droplets are probably passed through the cytoplasmic bridge from the nurse cell to the oocyte. Yolk formation includes different mechanisms and materials of different origin. Autosynthetic yolk formation predominates during the first intraovarial growth phase. After detachment of oocyte-nurse cell-complexes from the gonad pinocytotic activity of nurse cells and particularly oocytes, increases considerably. The existence of coated vesicles suggests that external sources of yolk precursors contribute to yolk formation. Prior to oocyte maturation the remnants of the nurse cell are incorporated by oocytes.     

Selective transport and packaging of the major yolk protein in the sea urchin

The major yolk protein of sea urchins is an iron-binding, transferrin-like molecule that is made in the adult gut. Its final destination though is the developing oocytes that are embedded in somatic accessory cells and encompassed by two epithelial layers of the ovary. In this study, we address the dynamics of yolk transport, endocytosis, and packaging during the vitellogenic phase of oogenesis in the sea urchin by use of fluorescently labeled major yolk protein (MYP). Incorporation of MYP into the accessory cells of the ovary and its packaging into yolk platelets of developing oocytes is visualized in isolated oocytes, ovary explants, and in whole animals. When MYP is introduced into the coelom of adult females, it is first accumulated by the somatic cells of the ovarian capsule and is then transported to the oocytes and packaged into yolk platelets. This phenomenon is specific for MYP and accurately reflects the endogenous MYP packaging. We find that oocytes cultured in isolation are endocytically active and capable of selectively packaging MYP into yolk platelets. Furthermore, oocytes that packaged exogenous MYP are capable of in vitro maturation, fertilization, and early development, enabling an in vivo documentation of MYP utilization and yolk platelet dynamics. These results demonstrate that the endocytic uptake of yolk proteins in sea urchins does not require a signal from their surrounding epithelial cells and can occur autonomous of the ovary. In addition, these results demonstrate that the entire population of yolk platelets is competent to receive new yolk protein input, suggesting that they are all made simultaneously during oogenesis.