共查询到18条相似文献，搜索用时 468 毫秒
1.
为了揭示拟穴青蟹受精膜形成机制,采用透射电子显微镜研究了其受精膜形成过程中环形颗粒的形成与胞吐。结果显示,拟穴青蟹精子入卵后,发生皮层反应而形成受精膜。皮层反应包括致密颗粒首先胞吐以及环形颗粒的相继多轮胞吐。每轮环形颗粒的胞吐参与到受精膜的平缓期、增厚期和举起期3个阶段。环形颗粒的形成主要发生在受精膜的增厚期,受精卵的皮层和靠近皮层的内质中都在形成大量的环形颗粒,并且迅速移至皮层质膜附近发生爆发性胞吐,参与到受精膜的快速形成中。环形颗粒的形成与2种卵黄颗粒以及脂滴密切相关,在皮层中发现了线粒体参与其中,推测在拟穴青蟹受精卵的皮层和内质中可能存在环形颗粒合成的两套不同机制。研究表明,卵黄颗粒、脂滴及环形颗粒在拟穴青蟹受精膜形成过程中发挥重要作用。 相似文献
2.
单环刺螠受精过程的细胞学观察 总被引：1，自引：0，他引：1
利用组织学和荧光显微镜对单环刺螠(Urechis unicinctus)受精过程中精子入卵以及核相变化进行了观察.结果表明:单环刺螠成熟卵呈卵圆形,核相处于生发泡尚未破裂的第1次成熟分裂前期.在(21±1)℃时,精卵混合后约5 min,精子由卵偏向植物极一侧入卵,受精膜开举起,继而精核发生第1次膨胀.直至受精后约25 min,受精膜完全举起;受精后10～50 min,卵核相继完成二次成熟分裂,分别形成第一极体和第二极体;受精后50～70 min,精核卵核分别膨胀,形成雄原核和雌原核,进而相向迁移,最后在卵的中央联合形成合子核.受精后70～90 min,受精卵完成第1次卵裂,形成2个大小相等的卵裂球.单环刺螠受精全过程历时约70 min,略长于多数海洋无脊椎动物的受精持续时间.本研究旨在为今后单环刺螠人工育苗和新品种的培育提供基础资料. 相似文献
3.
采用透射电子显微镜研究了拟穴青蟹受精膜形成过程中线粒体的变化及其功能。结果显示,大量线粒体首先高度密集于即将发生胞吐的皮质中;随着胞吐的发生,线粒体也随之快速分散到皮层反应部位,线粒体通过分裂、出芽等方式而迅速增多,内质中的线粒体大量向皮质迁移,参与皮层反应;当受精膜开始举起时,线粒体多聚集在新质膜下,参与新质膜的修复和形成;受精膜完全举起后,皮质中的线粒体迅速减少。线粒体在形态、数量及分布等方面的变化,能够反映受精膜形成不同阶段生理活动的旺盛程度以及需能情况,并从细胞水平阐释受精膜形成机制。 相似文献
4.
兴国红鲤同草鱼杂交的受精细胞学研究 总被引：15，自引：0，他引：15
兴国红鲤与草鱼杂交虽属亚科间的远缘杂交,却符合鲤科鱼类一般的受精规律,精子由唯一的受精孔道进入卵内,单精入卵。受精的适当时间是在卵细胞第二次成熟分裂的中期。受精后7分钟形成精子星光。接着雄性原核、雌性原核先后形成,并逐渐靠拢;受精后40分钟两性原核结合(水温21℃);受精后45—50分钟出现新个体的第一次卵裂。说明草鱼精子对兴国红鲤成熟卵细胞不仅起激动作用,而且参与了遗传物质的组成。此系亚科间远缘杂交具有生活力的生物学基础。实验发现:在特定的条件下,同一批受精卵中,多倍体,单倍体,雌发育可能同时存在。本文还比较分析了常见的几种鲤科鱼类及其杂种受精的过程。 相似文献
5.
采用人工授精,组织学、超微结构技术等方法对胭脂鱼(Myxocyprinus asiaticus)受精卵进行细胞学观察。结果表明:胭脂鱼卵子动物极卵壳仅有一受精孔,属单精受精。精孔器为深凹陷,短孔道型。在17～18℃水温条件下,受精后3 s精子开始穿过精孔管,受精后5 s进入卵子;受精后10 s形成精子星光;受精后15 min,卵子处于第二次减数分裂后期;受精后20 min,第二极体形成;受精后90 min,雌雄原核融合;受精后140 min,受精卵进入第一次有丝分裂中期;受精后180 min,第一次有丝分裂结束,二细胞形成。研究发现:成熟卵子精孔器内无精孔细胞及其他物质,和其他大多数硬骨鱼相似,精孔管内径2.42μm,而精子头部直径与其接近;同时精孔器前庭内壁有许多嵴突,孔洞顺螺旋排列,这些结构特点提示其是造成胭脂鱼单精受精的原因之一。本研究旨在为胭脂鱼人工繁殖技术的研究及其保护管理提供基础资料。 相似文献
6.
7.
通过显微镜及连续切片技术,研究了美洲鲥(Alosa sapidissima)胚胎发育过程中的形态学及组织学特征.结果显示,在孵化温度为(21.0±0.5)℃的条件下,美洲鲥受精卵经过71 h 15 min大量孵化出膜,其胚胎发育阶段主要分为6个时期.受精卵第1-5次卵裂均为经裂,第6次卵裂(64细胞期),纬裂出现,胚盘被分为外部的包被层和内部的深层细胞两部分.受精6 h 2 min,内外卵黄合胞体层形成.受精7h 40 min,囊胚腔出现.受精10 h 39 min,胚盘下包30％,胚盾形成;受精14 h 50 min,下包50％,三胚层形成;受精17 h 33 min,下包75％,神经板形成;受精21 h 13 min,下包90％,脑原基、视囊、脊索原基和体节出现;受精24h 15 min,完全下包,神经胚、听囊、前脑、中脑及后脑出现.受精24 h 55 min,克氏囊形成.受精35 h 44 min,心脏和消化管出现;42h50 min肾小管形成;47 h 35 min克氏囊消失;60 h 15 min角膜出现.70h 15 min,仔鱼大量出膜,初孵仔鱼具有一个大而均质的卵黄囊,上面布有明显的色素.美洲鲥胚胎发生发育的特征与大多数报道的硬骨鱼类类似,但在分化发育的时序上具有较大的差异. 相似文献
8.
锯缘青蟹卵膜变化与卵子附着研究 总被引：13，自引：1，他引：12
利用光镜和电镜观察了锯缘青蟹成熟卵及其受精后卵膜变化和卵子附着特征。锯缘青蟹成熟卵子卵膜有三层即外层、内层和质膜。卵子产出后,无论受精与否,外层和内层卵黄膜形成壳膜,与卵子附着有关。刚产出的卵子卵膜具有溶胶性和延展性,卵子与刚毛表面之间或卵子之间接触便粘在一起,由于刚毛摆动和卵子的重力作用,形成卵柄或卵索。卵子受精后,发生皮层反应形成受精膜。由壳膜和受精膜构成的孵化膜为初级卵膜,保护胚胎发育,直至 相似文献
9.
刺参受精及早期胚胎发育过程的细胞学观察 总被引：1，自引：1，他引：0
采用HOECHST 33258染色荧光显微方法,对刺参成熟未受精卵以及受精过程中精子入卵、极体排放、雌雄原核的形成与结合、早期卵裂以及多精入卵等细胞学进行了研究。结果显示,刚产出的刺参成熟未受精卵呈圆形,核相处于第一次成熟分裂中期;在水温22~23 ℃、盐度29条件下进行受精,受精后12 min,完成第一次成熟分裂,释放第一极体;受精后20 min,大部分受精卵完成第二次成熟分裂,放出第二极体。受精后35 min,雌、雄原核开始在卵中央发生染色体联合;受精后80 min,部分受精卵完成第一次卵裂,受精后100 min,部分受精卵完成第二次卵裂。刺参在受精过程中存在极少数的多精入卵现象。 相似文献
10.
《渔业科学进展》2017,(5)
通过显微镜及连续切片技术,研究了美洲鲥(Alosa sapidissima)胚胎发育过程中的形态学及组织学特征。结果显示,在孵化温度为(21.0±0.5)℃的条件下,美洲鲥受精卵经过71 h 15 min大量孵化出膜,其胚胎发育阶段主要分为6个时期。受精卵第1–5次卵裂均为经裂,第6次卵裂(64细胞期),纬裂出现,胚盘被分为外部的包被层和内部的深层细胞两部分。受精6 h 2 min,内外卵黄合胞体层形成。受精7 h 40 min,囊胚腔出现。受精10 h 39 min,胚盘下包30%,胚盾形成;受精14 h 50 min,下包50%,三胚层形成;受精17 h 33 min,下包75%,神经板形成;受精21 h 13 min,下包90%,脑原基、视囊、脊索原基和体节出现;受精24 h 15 min,完全下包,神经胚、听囊、前脑、中脑及后脑出现。受精24 h 55 min,克氏囊形成。受精35 h 44 min,心脏和消化管出现;42 h50 min肾小管形成;47 h 35 min克氏囊消失;60 h 15 min角膜出现。70 h 15 min,仔鱼大量出膜,初孵仔鱼具有一个大而均质的卵黄囊,上面布有明显的色素。美洲鲥胚胎发生发育的特征与大多数报道的硬骨鱼类类似,但在分化发育的时序上具有较大的差异。 相似文献
11.
Triploid induction in Australian greenlip abalone, Haliotis laevigata (Donovan), was conducted by blocking the formation of the second polar body using cytochalasin B (CB). Twenty minutes after fertilization, the zygotes of greenlip abalone were treated with four CB concentrations (0, 0.25, 0.5 and 0.75 mg L−1) for 10, 15 and 20 min. The ploidy of resultant larvae was determined using flow cytometry at 72-h post fertilization. Our study showed that fertilization, hatching, survival and induced triploidy of abalone larvae were significantly affected by the CB concentration and treatment duration. The effective range of CB concentration for triploid induction on greenlip abalone was 0.5–0.75 mg L−1 with an induction duration of 10–15 min. The results indicate that the most effective treatment combination for triploid induction in greenlip abalone is 0.5 mg CB L−1 for 15 min starting at 20-min post fertilization. 相似文献
12.
Marcelo Pimenta de Amorim Bruno Vilaça Campos Gomes Yuri Simões Martins Yoshimi Sato Elizete Rizzo & Nilo Bazzoli 《Aquaculture Research》2009,40(2):172-180
The silver catfish, Rhamdia quelen , is endemic to North, Central and South America with high aquaculture potential and wide acceptance in the market. Breeder fish were subjected to induced reproduction through hypophysation using a crude common carp pituitary extract. Egg characteristics, oocyte surface ultrastructure and histology of larval ontogenesis until whole yolk resorption were described for the first time for this species. Oocytes and semen were obtained by manual extrusion, and fertilization was conducted using the dry method. After fertilization, eggs were kept in incubators at 24 °C. The embryonic development was monitored using a stereomicroscope every 10 min until hatching. To analyse the larval development, larvae samples were collected from incubators daily until the fifth day, fixed in Bouin's fluid and subjected to routine histological techniques. The oocyte extrusion occurred 8 h after the second hormone dose at 26 °C. The oocytes were spherical, non-adhesive and yellow, with a diameter of 1471.75±47.63 μm. Scanning electron microscopy revealed a thin jelly coat covering the zona radiata in the animal pole around the micropyle. The blastopore closure occurred within 8 h after fertilization, and the fertilization rate was 79.9±5.2% at 24 °C. Embryonic development was completed within 25 h 30 min after fertilization. The complete resorption of the yolk and the formation of the digestive system organs and the mouth opening occurred on the fifth day, indicating a need for exogenous feeding. The results of this study provide information important for improvement in R. quelen culture and management. 相似文献
13.
The Biofloc Technology System (BFT) is characterized by stimulating the development of a microbial community that acts mainly in the maintenance of water quality but also promotes other benefits such as increased productivity, biosafety and serves as a supplementary source of food for reared animals. Two main groups of bacteria are involved in nitrogen removal in this system: heterotrophic bacteria and autotrophic nitrifying bacteria, present in the aggregates. Different fertilization techniques can be used for the formation and maintenance of bioflocs, depending on which group of bacteria the predominance is preferred. This study aimed to analyze the effect of different organic fertilization techniques on the bioflocs establishment, amount of water used, the production of suspended solids and the growth performance of Litopenaeus vannamei reared in the BFT System. Shrimp juveniles were stocked in 150-liter tanks at a stocking density of 300 shrimps/m³. Three treatments (in triplicate) were tested using different fertilization techniques: 1) without supplementary organic fertilization; 2) organic fertilization according to nominal ammonia reading (heterotrophic/chemoautotrophic = “mixed” system) and 3) organic fertilization according to estimated ammonia production (heterotrophic). The temperature, salinity, dissolved oxygen, pH, ammonia, nitrite, nitrate, alkalinity and total suspended solids (TSS) of the water were monitored. The water quality parameters were influenced by the treatments with differences found in the concentrations of ammonia, nitrite, nitrate, pH, alkalinity and TSS. Ammonia levels were higher in control treatment since no organic fertilization was performed. Nitrite levels were lower in heterotrophic system since the nitrifying pathway was suppressed due to daily fertilization, also resulting in lower nitrate levels. There were significant differences in the growth performance parameters, with the highest final weight and yield, as well as the lowest FCR, found in the mixed treatment. There were no significant differences among survival. The mixed system treatment used less water during production cycle compared to other treatments while the volume of solids removed was almost four times greater in the heterotrophic treatment compared to the others. These results show that adopting a mixed heterotrophic/chemoautotrophic biofloc system improves shrimp growth performance, optimize water use and decrease solids production. 相似文献
14.
对人工干法授精、微量充气孵化条件下星突江鲽的胚胎发育进行了研究。星突江鲽受精卵为分离的球形浮性卵,无油球、卵膜薄、光滑且透明,具弹性。吸水前卵径为0．66～0．70mm,吸水后为0．91～1．06mm。根据胚胎发育的外部形态及典型特征将星突江鲽胚胎发育过程划分为卵裂期、囊胚期、原肠期、神经胚期、胚孔关闭、眼泡和肌节形成、尾芽形成、晶体出现、听囊出现、出膜前期和出膜期11个连续的典型时期。在11±0．5℃水温下,受精卵经过101h仔鱼脱膜孵出。初孵仔鱼全长2．3～2．5mm,卵黄囊长径1．075～1．25mm,短径0．60～0．675mm。 相似文献
15.
对施氏鲟Acipenser schrenckii♀×西伯利亚鲟A.baeri♂进行人工繁殖,观察杂交子代的胚胎发育过程。结果表明,在水温15~22℃时,杂交鲟胚胎发育历时141~151 h,所需总积温为2 608.5~2 793.5℃·h。施氏鲟成熟卵为多黄卵,卵裂呈特殊的辐射裂,受精后胚盘隆起不明显。根据对施氏鲟♀×西伯利亚鲟♂杂交子代胚胎发育外部形态及典型特征的观察,将胚胎发育分为受精卵、卵裂期、囊胚期、原肠胚期、大小卵黄栓塞期、神经胚期、眼囊形成期、心脏形成博动期和孵出期9个时期。 相似文献
16.
将大珠母贝精子经不同脉冲循环数、脉冲数和不同脉冲幅度处理后，与卵子受精，然后观察受精和发育情况并进行统计分析，根据受精率确定最佳参数组合为：脉冲循环数6、脉冲数2^8和脉冲幅度6KV。此前用电击参数为脉冲循环数6、脉冲数2^7和脉冲幅度10KV进行了大珠母贝转基因实验，获得转基因阳性贝。 相似文献
17.
Evaluation of cytochalasin B (CB) treatments for triploidy induction in the blacklip abalone, Haliotis rubra (Leach, 1814) 总被引：2，自引：0，他引：2
The effectiveness of cytochalasin B (CB) treatments for inducing triploidy was evaluated in the blacklip abalone Haliotis rubra (Leach, 1814) in two orthogonal design experiments. The first experiment employed three dosages (DSs) of 0.25, 0.5 and 1.0 mg CB L?1, three starting times (STs) of 5, 15 and25 min post fertilization and three treatment durations (TDs) of 10, 20 and 40 min, for a total of 27 treatments. The second experiment comprised of two DSs of 0.25 and 0.5 mg CB L?1, five STs of 5, 15, 20, 25and 30 min post fertilization, and three TDs of 10, 20 and 40 min, for a total of 30 treatments. Water temperature was held at 17.5–18.5°C. Day 3 larvae were sampled for triploidy using flow cytometry (FCM) and survival. Optimal inductions were treatments starting at 15 or 20 min post fertilization and continuing for 40 min, and those initiated 25 or 30 min post fertilization for 20 or 40 min, using 0.5 mg CB L?1. These treatments were all targeted at inhibition of the second polar body (PB2) formation and yielded triploidy rates of 84.8–89.5% coupled with (relative) survival rates of 20.1–52.1% in the first experiment, and corresponding rates of 86.5–96.5% and 33.0–74.1%, respectively, in the second experiment. A common and essential feature of these optimal conditions is that treatment must fully span the period of time for most of the eggs to extrude PB2. Treatments that resulted in suppression of the first polar body (PB1) formation induced triploidy levels below 71.5% and 57.6% in experiments 1 and 2 respectively. Treatments that had overlapping effects on both PB1 and PB2 extrusion led to triploidy rates above 80% but very low survival rates of 1.8% and 5.4% in experiments 1 and 2 respectively. 相似文献
18.
I Babiak J Glogowski M Luczynski K Goryczko S Dobosz H Kuzminski 《Aquaculture Research》1998,29(5):337-340
The goal of the present study was to examine individual male potency in rainbow trout, Oncorhynchus mykiss (Walbaum), expressed as the fertilization ability of fresh and cryopreserved sperm. One female and four males bearing genetic markers enabling determination of the progeny paternity were chosen as gamete donors. Samples of eggs were inseminated with sperm from separate individuals or with pooled sperm. Genetic examination of the progeny obtained after fertilization of eggs with pooled milt showed differences in male potency. The proportions of offspring sired by four individual males after fertilization of eggs with the fresh milt were similar to those obtained after fertilization with cryopreserved milt (correlation r = 0.95; n = 4; P < 0.05). These proportions did not correlate with the proportions of progeny resulting from fertilization of eggs when sperm was not pooled. 相似文献