~(60)Coγ射线对柑桔大实蝇Dacus citri雌虫生殖细胞的影响     

张维  李元英 《核农学报》1990,4(2):115-119

本文研究了柑桔大实蝇的卵子发生及(60)~Coγ射线对卵子发生的影响。作者将大实蝇的卵子发生划分为8个阶段。经观察,蛹期的卵子发生处于原囊时期,此期对辐射较敏感。用6、9、12、15krad辐照处理羽化前2天的蛹,都能导致雌虫不育,使大部份卵母细胞的发育停于第4—5阶段,不能发育为正常的卵。  相似文献   

Energy acquisition and allocation to egg production in relation to fish reproductive strategies          下载免费PDF全文

Richard S McBride  Stylianos Somarakis  Gary R Fitzhugh  Anu Albert  Nathalia A Yaragina  Mark J Wuenschel  Alexandre Alonso‐Fernández  Gualtiero Basilone 《Fish and Fisheries》2015,16(1):23-57

Oogenesis in fishes follows a universal plan; yet, due to differences in the synchrony and rate of egg development, spawning frequency varies from daily to once in a lifetime. Some species spawn and feed in separate areas, during different seasons, by storing energy and drawing on it later for reproduction (i.e. capital breeding). Other species spawn using energy acquired locally, throughout a prolonged spawning season, allocating energy directly to reproduction (i.e. income breeding). Capital breeders tend to ovulate all at once and are more likely to be distributed at boreal latitudes. Income breeding allows small fish to overcome allometric constraints on egg production. Income breeders can recover more quickly when good‐feeding conditions are re‐established, which is a benefit to adults regarding bet‐hedging spawning strategies. Many species exhibit mixed capital‐ and income‐breeding patterns. An individual's position along this capital–income continuum may shift with ontogeny or in relation to environmental conditions, so breeding patterns are a conditional reproductive strategy. Poor‐feeding environments can lead to delayed maturation, skipped spawning, fewer spawning events per season or fewer eggs produced per event. In a few cases, variations in feeding environments appear to affect recruitment variability. These flexible processes of energy acquisition and allocation allow females to prioritize their own condition over their propagules' condition at any given spawning opportunity, thereby investing energy cautiously to maximize lifetime reproductive value. These findings have implications for temporal and spatial sampling designs, for measurement and interpretation of fecundity, and for interpreting fishery and ecosystem assessments.  相似文献   

孔雀鱼雌性生殖器官组织结构及卵子发生的研究     

王晓艳  王莎莎  赵玉超  刘永  孙帆  郭恩棉 《南方水产》2014,(1):16-20

应用光镜技术研究了孔雀鱼（Poecilia reticulata）雌性生殖器官组织结构和卵子发生的特点,以期为孔雀鱼的良种繁育工作提供基础资料。结果表明,孔雀鱼雌性生殖器官由卵巢、卵子输送管和泄殖孔构成。卵子发生过程经历了6个时相：第Ⅰ时相主要为卵原细胞;第Ⅱ时相是处于小生长期的初级卵母细胞,形成生长环、卵黄核和单层扁平滤泡细胞膜;第Ⅲ时相是进入大生长期的初级卵母细胞,卵黄开始积累,形成2层滤泡细胞膜和2层卵包膜;第Ⅳ时相为发育晚期的初级卵母细胞,细胞发生了极化,卵包膜发育完善;第Ⅴ时相发育成熟,卵黄颗粒凝结呈块状,卵黄泡主要分布于细胞膜内缘,滤泡细胞膜萎缩;第Ⅵ时相是闭锁卵泡,被滤泡细胞消化和吸收转变为卵巢内结缔组织。  相似文献   

The observed oogenesis impairment in greater amberjack Seriola dumerili (Risso, 1810) reared in captivity is not related to an insufficient liver transcription or oocyte uptake of vitellogenin          下载免费PDF全文

Chrysovalentinos Pousis  Constantinos C Mylonas  Caterina De Virgilio  Gemma Gadaleta  Nicoletta Santamaria  Letizia Passantino  Rosa Zupa  Maria Papadaki  Ioannis Fakriadis  Rosalia Ferreri  Aldo Corriero 《Aquaculture Research》2018,49(1):243-252

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养殖金乌贼卵子发生和卵巢发育的组织学观察   总被引：1，自引：1，他引：0  

尹亚南  刘长琳  胡鹏  张金勇  柳淑芳  庄志猛  薛同明 《中国水产科学》2018,25(3):503-511

为了深入了解金乌贼(Sepia esculenta Hoyle)的生殖生理特性,本研究采用解剖学方法及组织切片技术,观察和描述了金乌贼卵巢形态和卵子各个时相结构特征及其变化规律。研究结果表明,金乌贼卵子发生过程的主要特征表现为,卵子成熟之前滤泡细胞一直存在且伴随着其结构变化,滤泡细胞解体与卵黄物质出现同步发生,卵黄物质从无到有再到大量积累直至充满整个卵母细胞,细胞核则随着滤泡细胞内折逐渐发生偏移直至最后消失。研究还发现金乌贼卵巢内卵子发生不同步且形态差异显著,未成熟的卵子粘连在卵巢基质上,依次环布于卵巢基质周围,越靠近中心,卵母细胞发育程度越低;成熟后的卵子游离在卵巢腔中,经过输卵管排出体外。根据卵巢内卵子的大小和形态、滤泡细胞形态及卵黄形成情况,将金乌贼卵子发生分为增殖期(卵原细胞期)、小生长期(无滤泡期,单层滤泡期,双层滤泡期)、大生长期(滤泡内折期,卵黄形成早期,卵黄形成晚期)、成熟期、退化吸收期共5个时期9个时相。卵巢发育分期则是以卵子时相为基础,根据卵巢的外观形态、性腺系数以及切面上优势卵子的时相,把卵巢分为Ⅰ~Ⅵ共6个时期。金乌贼卵巢发育和卵子发生的动态观察与描述,对丰富头足类繁殖生物学理论及提升人工繁殖技术都具有重要意义。  相似文献   

福寿螺卵巢发育与卵子发生的组织学研究   总被引：1，自引：1，他引：0  

赵永超  严志会  吴帆  郑宏涛  李海云  章家恩 《华南农业大学学报》2016,37(3):95-99

【目的】研究福寿螺Pomacea canaliculate卵巢发育各期的主要典型特征。【方法】采用组织切片和苏木精-伊红(H.E)染色法,对入侵生物福寿螺的卵巢发育过程、卵母细胞发育各期的显微形态进行了观察和研究。【结果】根据福寿螺卵巢发育的组织学特征,将其发育过程分为5个时期:增殖期、生长期、成熟期、排放期和休止期。在卵巢发育过程中,卵母细胞发生一系列形态结构变化,最终发育为成熟的卵子。福寿螺卵子的形成依次经过卵原细胞期、卵黄合成前期、卵黄合成后期和成熟期。【结论】研究探明了福寿螺的卵巢为管状分支型腺体,卵原细胞经历了5个发育时期形成了成熟的卵子,并分析了福寿螺强大生殖力的原因。  相似文献   

香螺卵母细胞营养方式的研究     

高岩  侯林  周革 《安徽农学通报》2008,14(11):36-38

利用电子显微镜观察香螺卵子的发生情况,在香螺卵子发生过程中,靠近卵母细胞的滤泡细胞生命非常旺盛.滤泡细胞的内质网非常发达,呈环状,中心有脂滴产生.滤泡细胞和卵母细胞之间的膜有小泡产生.卵母细胞内部的内质网不发达;线粒体的嵴退化,内部有脂滴产生,因此推断香螺卵母细胞的营养方式为自体合成和异体合成两种.  相似文献   

Histological characterization of the maturation stages of the ovarian follicles of the goldfish Carassius auratus (Linnaeus, 1758)     

Maria Leonor Ferrão  Maria João Rocha  Eduardo Rocha 《Anatomia, histologia, embryologia》2020,49(6):749-762

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Identification of chorion genes and RNA interference-mediated functional characterization of chorion-1 in Plutella xylostella          下载免费PDF全文

DONG Shi-jie  LIU Bo  ZOU Ming-min  LIU Li-li  CAO Min-hui  HUANG Meng-qi  LIU Yan  Liette VASSEUR  YOU Min-sheng  PENG Lu 《农业科学学报》2022,21(11):3278-3292

Choriogenesis is the last step of insect oogenesis, a process by which the chorion polypeptides are produced by the follicular cells and deposited on the surface of oocytes in order to provide a highly specialized protective barrier to the embryo. The essential features of chorion genes have yet to be clearly understood in the diamondback moth, Plutellaxylostella, a worldwide Lepidoptera pest attacking cruciferous crops and wild plants. In this study, complete sequences for 15 putative chorion genes were identified, and grouped into A and B classes. Phylogenetic analysis revealed that both classes were highly conserved and within each, branches are also species-specific. Chorion genes from each class were located in pairs on scaffolds of the P. xylostella genome, some of which shared the common promoter regulatory region. All chorion genes were highly specifically expressed in the P. xylostella adult females, mostly in the ovary with full yolk, which is a crucial period to build the shells of the eggs. RNAi-based knockdown of chorion-1, which is located on the Px_scaffold 6 alone, although had no effect on yolk deposition, resulted in smaller eggs and sharply reduced hatchability. Additionally, inhibition of PxCho-1 expression caused a less dense arrangement of the columnar layers, reduced exochorion roughness and shorter microvilli. Our study provides the foundation for exploring molecular mechanisms of female reproduction in P. xylostella, and for making use of chorion genes as the potential genetic-based molecular target to better control this economically important pest.  相似文献   

Cytological abnormalities in the ovaries of triploid yellowtail flounder,Limanda ferruginea (Storer)     

A.?J.?ManningEmail author  M.?P.?M.?Burton 《Fish physiology and biochemistry》2003,29(4):269-273

Abnormal oocytes were detected in the ovaries of triploid yellowtail flounder of three years of age. Triploidy in these females had been induced artificially by hydrostatic pressure shock. Binucleate oocytes were found in the ovaries of six different triploid females. These cells were always small and in a primary growth stage. Cytoplasmic vacuoles, presumed to be due to nucleoplasmic extrusion, was another abnormal feature observed in two primary growth oocytes, each seen in a separate female. The appearance of binucleate oocytes in triploid females, not previously noted in diploid yellowtail flounder, is proposed to be an ephemeral phenomenon associated with the triploid condition.  相似文献