曼氏无针乌贼的卵子发生及卵巢发育

采用组织学方法对人工养殖曼氏无针乌贼(Sepiella maindroni)卵子发生、卵巢发育周期进行组织学、细胞学观察。根据细胞大小、胞核形态及卵母细胞与滤泡细胞的关系,将曼氏无针乌贼卵子发生划分为卵原细胞期、卵母细胞期、成熟期和退化吸收期4个阶段,并阐述了各期卵母细胞的组织学特征。曼氏无针乌贼卵子发生过程具有种的特异性,大约孵化出膜12 d的乌贼可见有卵原细胞,此后进入增殖期。卵母细胞属于典型的滤泡型,发育过程中同时存在同步性与异同步性;卵母细胞无初级卵膜,只有次级卵膜和三级卵膜,次级卵膜由滤泡细胞分泌,三级卵膜由输卵管腺、缠卵腺以及墨囊分泌物共同构成。通过对卵巢的外观形态和组织学观察,将曼氏无针乌贼卵巢发育划分为6个时期。     

福寿螺卵巢发育与卵子发生的组织学研究

【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。     

香螺卵母细胞营养方式的研究

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.     

养殖金乌贼卵子发生和卵巢发育的组织学观察

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。     

Identification of chorion genes and RNA interference-mediated functional characterization of chorion-1 in Plutella xylostella

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.     

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

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.     

圆口铜鱼卵巢发育及卵子发生的初步研究

对采于长江木洞江段和金沙江攀枝花江段的165尾圆口铜鱼进行了常规解剖,显微结构观察,结果表明：卵巢发育可分为Ⅰ～Ⅴ期。Ⅰ期卵巢较细,呈线状,以卵原细胞为主。Ⅱ期卵巢体积增加,呈“V”形;第2时相卵母细胞进入小生长期,产卵板明显;细胞质中出现卵黄核和生长环,周围有零散滤泡细胞。Ⅲ期卵巢因血管分布呈微红色,第3时相卵母细胞进入大生长期,核仁外排明显;液泡、卵黄颗粒及放射带出现,形成单层扁平滤泡层。Ⅳ期卵巢呈囊状,血管分布丰富,可见卵粒;第4时相卵母细胞,液泡逐渐退化,卵黄颗粒充满细胞质,滤泡层分化为2层。     

孔雀鱼雌性生殖器官组织结构及卵子发生的研究

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。