诱导栉孔扇贝雌核发育时精子入卵的扫描电镜观察

取栉孔扇贝 (Chlamysfarreri)精子在 80 0 μW/(cm2 ·s)的紫外线下辐射 ,然后与正常卵子受精 ,每隔 0 .5min取“受精卵”固定。在扫描电镜下连续观察精子的入卵过程 ,然后与正常精子的入卵过程进行比较。结果表明 ,紫外辐射后的精子可以划分为 3种类型 :I类精子 ,基本无明显变化 ,可以激发卵黄膜举起形成受精膜 ,同时诱发卵子发生皮层反应 ,在受精锥的作用下正常入卵 ,但入卵的时间较正常精子晚 ;II类精子 ,顶体膜破裂 ,顶体丝伸出 ;III类精子 ,顶体丝伸出 ,鞭毛脱落。由于II、III类精子在紫外辐射条件下诱发了顶体反应 ,融解卵膜的酶提前释放 ,因而不能入卵。精子鞭毛的脱落 ,使精子丧失了运动能力 ,是导致卵表面附着的精子数量较少的原因之一。无论是正常精子还是辐射后的精子 ,入卵后在卵表面都留下一个类似受精孔的通道。实验组中未发现有多精入卵现象     

史氏鲟精子入卵过程的扫描电镜观察

史氏鲟(Acipenserschrencki)隶属鲟形目(Acipenseriformes)、鲟科(Acipenseridae)、鲟属(Acipenser),是黑龙江特产和重要的经济鱼类之一,为淡水定居种类。鲟鱼是古老的生物类型,世界上约有28种,仅分布于北半球。由于自然环境的改变和人类活动的影响,所有鲟鱼均处于不同程度的濒危状态,有的已近灭绝[1,2]。我国有8种鲟鱼,其中黑龙江2种,即史氏鲟和达氏鳇。近年来,随着人工养殖技术的提高和完善,史氏鲟成为国内最主要的鲟鱼养殖种类。有关史氏鲟人工养殖、基因组DNA含量、胚胎发育等国内有较多研究,而对受精生物学方面研究尚未见报道。特殊…     

锯缘青蟹精子入卵过程的扫描电镜观察

利用扫描电镜详细观察了锯缘青蟹精子入卵的过程。精子以其核突起附着在卵膜上,并迅速发生顶体反应。顶体反应时,顶体囊外翻,顶体管前伸,精子核辐射臂收缩,并拖至顶体囊的后部。顶体管迅速穿过卵黄膜,携带核物质一同进入卵子。锯缘青蟹为多精着卵,数精入卵。本文同时探讨了精子顶体反应机制以及受精过程卵子的作用。     

索氏六须鲶受精早期精子入卵的扫描电镜观察

用扫描电镜对索氏六须鲶受精早期精子入卵过程进行系统观察,结果显示,索氏六须鲶在受精后３０－６０ｓ内完成精子入卵过程,在受精后２ｍｉｎ精子开始逐渐解体,直至受精后１５ｍｉｎ左右,受精卵外精子全部解体。通过对精子和卵子的精孔管的测量判定索氏六须鲶精方式为单精受精。     

黄鳝精子活力检测和精子入卵早期过程观察

采用Olympus3×51相差系统显微镜和SQIAS—1000彩色精液质量图文分析系统检测黄鳝精子活力。结果表明,在NaCl溶液浓度为0～0.3%时,黄鳝精子激活比例随溶液浓度升高而极显著增加(P<0.01);当NaCl浓度达到0.7%时,精子激活比例、直线运动速度和鞭毛摆动频率均显著(P<0.05)或极显著(P<0.01)降低。扫描电镜观察显示:黄鳝成熟卵卵壳膜上的精孔区呈漏斗状凹陷,其底部中央可见一精孔管外孔,口径约4.22±0.66μm;黄鳝精子入卵速度缓慢,受精过程较长,从精子附着于卵球表面到精孔管完全堵塞,约30s～5min。     

大菱鲆成熟精子、卵子及精子入卵早期过程的电镜观察

通过人工授精和电镜技术,观察和描述了大菱鲆Scophthalmus maximus成熟精卵的形态、精子入卵的早期过程及精子入卵过程发生的一系列形态结构变化。大菱鲆卵子表面均匀地布满纵横交错的网纹,并整齐地分布许多微小孔,在动物极有一个受精孔。大菱鲆精子为无顶体类精子,由头部、中片和尾部三部分组成,中片有9～14个圆形线粒体。大菱鲆精子入卵速度非常快,授精后0～5s已经有精子通过受精孔(Micropyle)进入卵子。精子入卵过程还伴随着其他一些结构的变化,如精孔管管壁边缘由锯齿状变为平滑的环状等。     

中国对虾精子入卵过程的观察

利用光镜和电镜对中国对虾精子入卵过程进行了观察。结果表明，精子的核物质籍胞吐作用穿过卵黄膜到达卵膜，其余部分则留在卵黄膜外。只有在卵子激活前到达卵膜的精子才能参与受精作用，其余的精子将被卵子激活所形成的胶质层推离卵子。中国对虾精子激活过程，没有发现顶体丝的形成。精子的入卵开始于卵子的皮层反应后期，此时精卵的接触逐渐密切，首先接触部位的卵膜稍有突起，然后开始下陷，同时这一部位的卵膜变得粗糙不平，随后卵膜解体，精子由此进入卵子。中国对虾精子的入卵位置是随机的，有多精入卵的现象。     

黄颡鱼精子入卵的扫描电镜观察

应用扫描电镜观察了黄颡鱼(Pelteobagrus fulvidraco)成熟卵和精子的形态、卵子对精子的应答反应、受精孔的数量与形态、受精方式与过程。结果显示:黄颡鱼精子为鞭毛型,头部近圆球形,无顶体,单尾;卵为圆球形,卵膜表面多嵴,且有15～16条宽度不同的小沟;卵表面仅有1个受精孔,精孔管口内径约2.8μm。黄颡鱼为单精受精,受精后30 s内完成精子入卵过程。     

中华沙塘鳢(Odontobutis sinensis)精子入卵过程扫描电镜(SEM)观察

为探讨中华沙塘鳢(Odontobutis sinensis)单精入卵机制,指导中华沙塘鳢人工繁育技术,采用扫描电子显微镜(SEM)对中华沙塘鳢精子和成熟卵子的形态和精子入卵过程予以观察,较为准确地描述了中华沙塘鳢精子和成熟卵细胞的形态与结构。结果显示,中华沙塘鳢精子头部为椭圆形,长轴约为2.25±0.25μm,短轴1.00±0.20μm,颈部较短。成熟卵细胞呈鲜艳黄色,呈圆球形,直径为1.30±0.02 mm,黏性卵,具黏着丝。观察发现,中华沙塘鳢精子能够准确通过成熟卵细胞的黏着丝达到受精孔,整个授精过程平均需要60 s完成,相对于其他科鱼类时间较长。中华沙塘鳢授精15 s,精子开始通过黏着丝;20 s大量精子进入筛网;25 s精子位于筛网孔内部,部分穿过筛网;55 s大量精子通过卵细胞黏着丝;60 s精子入卵;120 s受精孔关闭。     

彭泽鲫(♀)与黑龙江野鲤(♂)的杂交利用研究

以彭泽鲫为母本、黑龙江野鲤为父本进行杂交，将杂交一代(F1)的生长速度、抗病力、群体产量、经济效益、同工酶、生物学性状等与双亲进行对比试验。结果表明，杂交一代(F1)具有明显的优势，其生物学性状及同工酶谱与母本彭泽鲫相似。     

湘云鲫、湘云鲤消化道的组织学研究

采用石蜡切片法和显微测量法研究了新型三倍体鱼－湘鱼鲫（Carassius auratus Triploid)，湘云鲤（Cyprinus carpio Triploid)消化道的组织结构，并探讨了消化道组织结构和食性之间的关系，结果表明：湘云鲫，湘云鲤食道和肠道壁均由粘膜层，粘膜下层，肌层，浆膜层4层组成，缺乏粘膜肌，二者消化道的组织结构与其各自的食性一致，二者食道粘膜上皮由单层柱状细胞和杯状细胞组成，这与其它鱼类的不同，湘云鲫比湘云鲤具有对食物更强的消化吸收能力；／湘云鲫，湘云鲤肠道可分为前肠，中肠，后肠3段。     

Colouring ornamental fish (Cyprinus carpio and Carassius auratus) with microalgal biomass

Koi carp and goldfish value increases with intensity of skin colour, which is an important quality criterion. Fish cannot fully synthesize their own carotenoid colourings and these must therefore be included in their diet. Two trials were undertaken to investigate skin colour enhancement in ornamental species (i.e. three chromatic varieties of koi carp (Cyprinus carpio), namely Kawari (red), Showa (black and red) and Bekko (black and white) and goldfish (Carassius auratus)) by feeding a dietary carotenoid supplement of freshwater microalgal biomass [Chlorella vulgaris, Haematococcus pluvialis, and also the cyanobacterium Arthrospira maxima (Spirulina)], using a diet containing synthetic astaxanthin and a control diet with no colouring added for comparison. In the first trial, five homogeneous duplicate groups of 25 juvenile koi carp (C. carpio) (initial mean body weight 24.6 ± 0.7 g) were fed, for 10 weeks, one of the four diets containing 80 mg colouring/kg diet. In the second trial, this procedure was repeated for five homogeneous duplicate groups of 25 goldfish (C. auratus) (initial mean body weight of 0.9 ± 0.1 g). Initial and final samples of skin along the dorsal fin were withdrawn, from five fish per group, for subsequent analysis of total carotenoid content (spectrophotometric analysis), and red hue (colorimetric analysis, CIE (1976) L* a* b* colour system). Growth and feed efficiency were not significantly different between groups administered by the various dietary treatments. In both trials, dietary carotenoid supplementation increased total skin carotenoid content. The more efficient colouring for koi carps was found to be C. vulgaris biomass, providing both maximum total carotenoid deposition and red hue for the three chromatic koi carp varieties studied, and particularly for the kawari variety. For goldfish the best colouring obtained, as ascertained by total carotenoid content, was also achieved using C. vulgaris biomass, and red hue was maximum when using H. pluvialis biomass.     

Influence of Egg Yolk on the Quality of Cryopreserved Spermatozoa of Common Carp,Cyprinus carpio

Cryopreservation of fish gametes can help in producing quality fish seeds. Success of cryopreservation is evaluated by the post-thaw motility of the spermatozoa. The changes in the seminal plasma during cryopreservation would alter the energy supply for the motility of the spermatozoa, and thus energy supplementation is found to be useful during cryopreservation. Cyprinus carpio spermatozoa were cryopreserved along with egg yolk as a co-cryoprotectant after 1:100 dilution with 0.85% physiological saline as extender and DMSO as cryoprotectant (85:15). The diluents contained egg yolk at three different concentrations, viz., T₁ (5%), T₂ (10%), and T₃ (15%). The diluted milt was equilibrated for 10 min at 5°C and loaded into 0.25 ml straws. The loaded straws were then frozen with LN₂ vapor for 5 min and immersed in liquid nitrogen. Observations were made once in 7 days for 42 days on motility parameters based on which the duration, score, pattern, and percentage were determined. There were significant differences in the motility duration between treatments, and egg yolk at 5% (T₁) concentration was found to support the cryopreserved spermatozoa better than the other concentrations; the difference in motility duration was statistically significant (P > 0.005).     

镉对鲤遗传毒性和外周血细胞数量的影响

将鲤(Cyprinus carpio)分别暴露于0.16、0.31、0.63、1.26 mg/L Cd2+溶液中,研究Cd2+对鲤外周血红细胞微核率、核异常率、红细胞和白细胞数量的影响,探讨Cd2+对鲤遗传毒性和外周血细胞数量影响的变化规律和趋势。结果显示:Cd2+对鲤红细胞微核率和核异常率的影响存在浓度-效应和时间-效应关系。与对照组相比,1.26 mg/L Cd2+组鲤在不同暴露时间的红细胞微核率和核异常率均极显著(P<0.01),核异常率在72 h显著(P<0.05)增加,72 h后表现为极显著(P<0.01)增加。Cd2+对鲤外周血淋巴细胞、单核细胞和嗜中性粒细胞比例的影响存在浓度-效应和时间-效应关系。相同Cd2+浓度下,鲤淋巴细胞比例随暴露时间增加先降低后上升,同一暴露时间淋巴细胞比例随Cd2+浓度增加而降低。相同Cd2+浓度下,鲤单核细胞和嗜中性粒细胞比例随暴露时间增加先升高后降低,同一暴露时间嗜中性粒细胞比例随Cd2+浓度增加而升高。研究表明,Cd2+对鲤具有遗传毒性效应,且随Cd2+浓度增加而增强。     

铬对鲤生长、血清离子和某些激素分泌活动的影响

将鲤(6月龄)饲养在Cr6 浓度系列:0、0.12、0.67、1.22、3.661、0.97和32.91mg.L-1的水体中40d,T0.12~T3.66组的绝对增重率和绝对增长率较对照鱼有增重的趋势;铬对鲤血清渗透压和血清离子的影响:自染毒T0.67组引起血清渗透压升高,血清Na 和Ca2 浓度较对照鱼也有明显提高;血清K 浓度有升高的趋势,仅T10.97组有显著差异;个别染毒组Mg2 浓度降低;铬对多数染毒鱼的Cl-浓度影响不明显。铬对血清激素水平影响:T3.66组的T3含量、T10.93组的T4含量以及T0.67组以上的高剂量染毒组的皮质醇含量均较对照鱼明显升高。多数铬处理组鲤肌肉的粗蛋白和粗脂肪含量较对照鱼降低。鱼体铬蓄积量大小依次为:肌肉<鳃<肝<肠。肌肉中铬含量超标(3.00mg.kg-1)为T32.91组鱼,肠中铬超标(2.24mg.kg-1)为T0.67组鱼。