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1.
静水压休克法诱导三倍体鲶鱼(silurus asotus L)的研究   总被引:1,自引:0,他引:1  
采用静水压休克法诱导三倍体鲶鱼。通过对受精时间、静水压力及持续施压处理时间三方面进行筛选试验的结果表明,鲶鱼卵受精4-5min,用600-649kg/cm^2的静水压力处理3min,可以获得100%的三倍体鲶鱼,而且胚胎存活率也较高,孵化率达对照组的90%以上,是静水压休克法诱导三倍体鲶鱼的最佳条件。三倍体鲶鱼的倍性用细胞遗传学方法验证。  相似文献   

2.
三倍体与二倍体泥鳅的组织细胞学比较   总被引:1,自引:0,他引:1  
为探明三倍体和二倍体泥鳅的组织细胞学差异,运用血液涂片及组织切片方法,对三倍体、二倍体泥鳅的红细胞及其细胞核的长轴和短轴,血液中血细胞的组成及仔鱼眼部构造等进行了比较.结果表明,三倍体泥鳅红细胞及其核的长轴均比二倍体的要大,其中前者红细胞核的长轴约为后者的1.12倍,红细胞体积、核体积分别约为后者的1.62和1.44倍.三倍体泥鳅红细胞的相对数量明显少于二倍体泥鳅,而嗜中性细胞、单核细胞及淋巴细胞则多于后者.此外,三倍体泥鳅眼部色素层细胞数量少于二倍体.  相似文献   

3.
对杂交三倍体泥鳅(4n♀×2n♂)的胚胎染色体进行了C带及染色体荧光原位杂交(FISH)分析,首次探讨了杂交三倍体泥鳅C带特征,为准确鉴别染色体提供依据,研究了核糖体5.8S+28S r DNA在杂交三倍体泥鳅胚胎中期染色体上的数目和位置。C带结果表明,杂交三倍体泥鳅的染色体C带包括臂端C带和着丝粒C带,没有发现臂间C带。M染色体只有1号染色体既有臂端C带又有着丝粒C带,但臂端C带均比着丝粒C带大,信号也比着丝粒的强;而其他M染色体及SM染色体、T染色体只有着丝粒C带。FISH分析显示,核糖体5.8S+28S r DNA清楚地定位在杂交三倍体泥鳅中期染色体中部着丝粒染色体(M)的端部区域,在杂交三倍体泥鳅中期染色体上可以检测到三簇杂交信号。该结果从分子细胞遗传学层面进一步证实了杂交三倍体泥鳅是含有三套染色体组的遗传三倍体。  相似文献   

4.
为探明三倍体和二倍体泥鳅的组织细胞学差异,运用血液涂片及组织切片方法,对三倍体、二倍体泥鳅的红细胞及其细胞核的长轴和短轴,血液中血细胞的组成及仔鱼眼部构造等进行了比较。结果表明,三倍体泥鳅红细胞及其核的长轴均比二倍体的要大,其中前者红细胞核的长轴约为后者的1.12倍,红细胞体积、核体积分别约为后者的1.62和1.44倍。三倍体泥鳅红细胞的相对数量明显少于二倍体泥鳅,而嗜中性细胞、单核细胞及淋巴细胞则多于后者。此外,三倍体泥鳅眼部色素层细胞数量少于二倍体。  相似文献   

5.
红鳍东方鲀三倍体诱导的初步研究   总被引:1,自引:0,他引:1  
王茂林  姜志强  李荣 《水产科学》2006,25(7):349-352
通过冷休克的方法诱导红鳍东方鲀的受精卵,孵化后的仔鱼,用PAS-Ⅲ型细胞流速仪测定其倍性,得到较高的三倍体诱导率。受精后8 min,0℃下处理15 min和受精后5 min,2℃下处理15min三倍体率最高,为100%;受精后8 min,4℃下处理10 min倍化率最低,为20%;其余几组的三倍体率为90%。正交试验结果表明,影响三倍体诱导率的主次顺序是处理时间、处理温度、处理起始时间。  相似文献   

6.
冷、热休克法诱导黄颡鱼三倍体的比较研究   总被引:5,自引:0,他引:5  
分别采用冷、热休克抑制第二极体释放的方法诱导黄颡鱼三倍体。结果表明,在卵受精后2min,5℃处理20min,胚胎时期的三倍体率达70%左右,孵化率50%左右,幼鱼时期三倍体(含嵌合体)的检出率为25%,此条件为冷休克处理的优化参数;在卵受精后2min,40℃处理2min,胚胎时期的三倍体诱导率达58%,孵化率为39%,幼鱼时期三倍体(含嵌合体)的检出率为40%,此条件为热休克处理的优化参数。正交分析得出,冷休克条件下起始休克时间是原肠期三倍化率和孵化率的重要影响因子,温度对畸形个体的产生有重要影响;热休克条件下,参考三倍体率、畸形率、孵化期相对存活率三者而言,休克温度均是重要因素。比较观察到冷休克处理组的胚胎受损情况严重,后期的成活率较热休克处理组要低,总体诱导效果逊于热休克处理组。  相似文献   

7.
热休克诱导黄颡鱼三倍体的研究   总被引:1,自引:0,他引:1  
以正交试验设计,采用热休克法研究了诱导三倍体黄颡鱼的适宜条件.试验结果表明,在卵受精后2 min,40 ℃持续处理2 min,三倍化率可达57.5%,原肠期相对存活率43.0%,孵化期相对存活率38.5%.分析了热休克处理的参数与三倍体出现率和胚胎相对存活率的关系,诱导参数中处理温度和诱导时机为重要因素,其次为持续时间.  相似文献   

8.
长江流域泥鳅与大鳞副泥鳅种质资源调查与研究   总被引:2,自引:1,他引:1  
对长江流域泥鳅和大鳞副泥鳅野生群体进行了系统资源调查,结果显示,二倍体泥鳅(2n)与多倍体泥鳅(3n,4n,5n)在长江流域均有分布,其中二倍体泥鳅数目占有绝对优势,少量多倍体泥鳅集中分布于长江流域中游地区及若干湖泊。此外,显著性分析表明,泥鳅和大鳞副泥鳅的雌性个体都显著大于雄性个体,两物种间个体大小无显著性差异。二倍体泥鳅的体长与体质量明显小于三倍体泥鳅及四倍体泥鳅,而三倍体泥鳅与四倍体泥鳅间无显著性差异。野生群体中,泥鳅雌性个体所占比例从上游到下游逐渐减少,大鳞副泥鳅无明显变化。相关性分析显示,泥鳅体质量与地域经度呈负相关,大鳞副泥鳅体质量与地域经度无显著相关性。研究表明,长江流域多倍体泥鳅和大鳞副泥鳅物种资源丰富。  相似文献   

9.
冷休克诱导大鳞副泥鳅雄核发育单倍体   总被引:4,自引:0,他引:4  
为探索诱导鱼类雄核发育单倍体的新方法及形成机制,以大鳞副泥鳅为研究对象,无须卵子失活,仅用冷休克诱导雄核发育单倍体,并对其后代的早期胚胎发育、染色体数目、分裂胚细胞学观察等进行了系统分析。早期胚胎发育结果显示,0℃与3℃处理组的孵化率分别为0.83%和57.42%,二者之间孵化率差异显著(P0.05),0℃和3℃处理组均表现出单倍体综合征。染色体倍性鉴定结果显示,0℃处理组染色体分布为18~27,单倍体率为81.40%,3℃处理组染色体分布为20~30,单倍体率为68.97%。分裂胚细胞学观察结果显示,3℃处理组受精后60 min,卵核和第二极体位于胚表面,有一同释放迹象。结果表明,对大鳞副泥鳅受精卵进行3℃冷休克处理60 min,可以成功诱导雄核发育单倍体,研究推测冷休克诱导大鳞副泥鳅雄核发育的细胞学机制是雌核和第二极体一同释放。  相似文献   

10.
冷休克法和静水压法人工诱导大黄鱼三倍体   总被引:7,自引:0,他引:7       下载免费PDF全文
同时采用冷休克法和静水压法进行大黄鱼(Pseudosciaena crocea Richardson)倍体诱导条件研究,同时比较适合条件下两种方法诱导效果差异以及大批量诱导组不同生长阶段三倍体榆出率的差别。结果表明:(1)冷休克法和静水压法都可成功诱导出大黄鱼二倍体。冷休克法适宜诱导条件为20℃培育水温下授精后3min,在3~4℃海水中处理8~10min;静水压法适宜诱导条件为同样培育水温下授精后3min,在静水压450kg/cm^2下处理3min。三倍体诱导率受处理时刻、处理时间和处理温度(或压力)3因素的影响。(2)综合三倍体诱导率、处理后受精卵原肠期存活率和仔鱼孵化率,静水压法诱导效果要明显优于冷休克法。(3)采用冷休克法进行大黄鱼三倍体大批量诱导,早期胚胎、初孵仔鱼和4月龄幼鱼三倍体检出率分别为34.03%、29.54%和14.81%。表明随生长发育诱导组三倍体检出率有下降趋势。  相似文献   

11.
Triploidy was induced in the turbot (Scophthalmus maximus, L.) by applying cold shocks shortly after fertilization. The combined effects of the timing of cold shock commencement after fertilization, cold shock duration and cold shock temperature were investigated. Ploidy was assessed by counting the number of nucleoli per nucleus (NOR) in larvae and also by measuring erythrocyte size in juveniles. A clear peak in triploidy induction was obtained when shocks were started between 6 and 7 min after fertilization at a pre-shock temperature of 13–14°C. With this timing, shocks of 20-min duration at 0°C gave >90% triploidy, with survival about 80% of the untreated controls. In order to ensure both high triploidy rates and high survival, it was necessary to carefully maintain the water temperature just below 0°C. Experiments with small and large volumes of eggs were performed in order to determine how changes in the relative volumes of eggs and chilled water could affect survival and triploidy induction. The best combination to induce triploidy in the turbot was as follows: shock commencement 6.5 min after fertilization, shock duration 25 min, and shock temperature between 0 and −1°C. With this combination, 100% triploidy could consistently be induced with survival 60% of the untreated control. This was successfully applied to a large volume of eggs (300 ml; 1 ml 800 eggs) in order to mass-produce triploid turbot. Triploids had lower survival rate than diploids at hatching but similar thereafter, with the ability to complete the different stages of larval rearing, indicating the viability to produce triploid turbot under farming conditions.  相似文献   

12.
Conditions for the induction of triploidy with cold shock of fertilized eggs of the spotted sand bass Paralabrax maculatofasciatus (Steindachner) were investigated. Different temperatures (12, 8 and 4 °C), timing of cold shock application (5, 10 and 15 min after fertilization) and duration of the shock (5, 10, 15 and 20 min) were tested. Triploidy was determined using flow cytometry at 12 h after larvae hatched. Triploids were produced only when the cold shock treatment was applied 5 min after fertilization. No significant difference was observed in the percentage of triploidy between temperature and the shock duration. At 8 and 4 °C, 100% triploidy was obtained at different durations of cold shock. Survival was significantly lower at 12 or 4 °C than at 8 °C. No significant difference was observed for shock duration at the temperature of 8 or 12 °C; however, at 4 °C, survival was significantly lower at longer durations. We recommend induction of triploidy by applying cold shock at 8 °C for a duration of 15–20 min starting at 5 min after fertilization, in the spotted sand bass.  相似文献   

13.
Triploidy in fertilized eggs of Penaeus semisulcatus was induced by temperature and chemical shocks. The eggs, which were obtained from the shrimp broodstock maintained at 29 C, were exposed to cold temperature (8, 10, 12, and 14 C) and 6‐dimetiloaminopurine (6‐DMAP) concentrations (100, 150, 200, and 250 μM) for different durations (4, 6, and 8 min) 9 min after spawning was detected. While the highest triploidy rate of 49.7 ± 4.5% was obtained with a 200 μM 6‐DMAP concentration for a duration of 8 min, the best mean triploidy rate of 45.5 ± 2.8% for cold shock was obtained at a temperature of 10 C for a duration of 8 min. Temperature and 6‐DMAP concentration did not have significant effect on triploidy rate (P > 0.05) but shock duration had significant effect on triploidy rate for individual cold temperature shock or 6‐DMAP chemical shock (P < 0.05). Although longer durations of shock agent increased the rates of triploid induction, they generally had an adverse effect on hatching rates in the study.  相似文献   

14.
Abstract.— Induction of triploidy and tetraploidy in Nile tilapia, Oreochromis niloticus , was investigated by heat shock, cold shock, hydrostatic pressure, and/or chemicals (cytochalasin A, B, and D). Additionally, efficacy of combined protocols was determined. Heat shock 10 min after fertilization induced triploidy when incubation temperature was 24 C but not when incubation temperature was 31 C. Heat shock of 40–41 C at 4–6 min after fertilization was effective in inducing up to 100% triploidy with hatchability similar to controls. Cold shock at 13 C for 45 min five min after fertilization induced 85–100% triploids. Heat shock and multiple heat shocking were the most effective treatments for the induction of tetraploidy. Two heat treatments of 41 C applied at 65 and 80 min after fertilization for 5 min each produced approximately 80% tetraploidy in hatched fry. Immersion of fertilized eggs in cytochalasin A, B, or D at concentrations up to 10 μg/L applied at various times and durations was ineffective in inducing triploidy or tetraploidy.  相似文献   

15.
Induction of triploidy in grass carp was accomplished by means of thermal shocks to eggs shortly after fertilization. Triploidy occurred most often with cold shocks at 5–7°C and at durations of 25–30 min starting 2.0–4.5 min after fertilization. Estimated percent triploid ranged from 50 to 100% on five occasions. With one exception, cold shocks of 5–7°C for less than 25 min did not induce triploidy, and cold shock durations of 30 min or longer generally resulted in 100% mortality. A heat shock of 40°C for 1 min, 4.75 min after activation, was the only heat treatment which produced triploidy (8%) with 81% surviving to the blastula stage. Fertilized eggs immersed in a solution of cytochalasin B (10 mg/l, 0.1% DMSO) for 10 min, 12 min after activation, resulted in 54% of the eggs surviving to the blastula stage with none found to be triploid.  相似文献   

16.
Production of sterile triploid red tilapia [Oreochromis mossambicus (Mozambique tilapia); Peters, 1852 × Oreochromis niloticus (Nile tilapia); Linnaeus, 1758] is an effective strategy to overcome their prolific breeding. Optimal conditions for cold-shock induction of triploidy in red tilapia were investigated by experimentally examining two variables: appropriate temperature of the shock and duration of shock treatment. A constant time after insemination of 4 min was used to determine the best combination of temperature (6, 7, 8, 9, 11, 13, 15 °C) with different durations of shock (10, 20, 30, 40, 50 min) with resultant ploidy level verified karyotypically. Shock duration for 30 min at a temperature of 9 °C was found most effective in producing maximum triploidy (98.7 %) with higher rates of hatching (63.2 %) and survival up to yolk-sac stage (75.8 %). The chromosome count confirmed that triploid percentages were higher when cold shock was used for longer durations at each temperature; however, hatching rates were generally decreased. The maximum triploid yield (82.1 %) obtained was higher than the yield obtained using heat shock (72.7 %) in red tilapia previously. The application of the results of this study has the potential to greatly improve the production of triploid red tilapia in commercial aquaculture.  相似文献   

17.
Argopecten nucleus is a small scallop from the Caribbean Sea and a relatively new species for aquaculture. One of the key challenges to develop the farming operations for this species from the current pilot scale to commercial level is to improve its harvest size. In this study, we tested three different methods for triploidy induction. Additionally, the effect of these protocols on survival, developmental rate and size of larvae and post‐larvae were assessed. Three different mechanisms to stimulate the inhibition of the release of the second polar body were tested; (1) cold shock (18°C); (2) 6‐dimethylaminopurine (6‐DMAP); (3) cytochalasin B (CB) and (4) dimethylsulphoxide (DMSO). The treatment with 6‐DMAP yielded the highest percentage of triploid larvae (39%). The survival and development rate, however, were higher in non‐treated larvae (control) than in the treatment groups. Interestingly, larvae from CB and the DMSO control groups exhibited lower growth rates in length than those from control and the other two treatments. No influence of the triploidy induction treatments was observed on post‐larvae survival, but the size of post‐larvae was larger for the cold shock treatment and DMSO control group. Our results indicate that the use of 6‐DMAP has the greatest potential to produce triploid larvae of A. nucleus without affecting negatively growth and survival of post‐larvae.  相似文献   

18.
Triploidy could reduce breeding activity in tilapia without the use of hormones. In this study, the effect of triploidy on survival, growth, and gender of a line of red hybrid tilapia (Oreochromis mossambicus X Oreochromis niloticus) was assessed relative to the performance of diploid siblings. Triploidy was induced by preventing second polar body extrusion by applying either heat or cold shock. Growth was similar for both ploidies during the first 90 days of culture. However, at the age of 120 days, the average body weight of triploids produced by heat shock (215.5 ± 3.61 g) was significantly higher than that of cold shock (192.7 ± 2.6 g) and the diploid control (191.9 ± 1.74 g). Survival among triploids was inferior to diploids. Percentage of males in the triploid population was 82.9% in the heat-shocked treatment group, 54.8% in the cold-shock treatment, and 50% in the diploid control. Maximum attainable weight of red tilapia was calculated by applying the Ford-Walford growth plot: 650 g (heat-shocked triploids), 490 g (cold-shocked triploids), and 440 g in the diploid control.  相似文献   

19.
The effects of thermal treatments on induction of triploidy in Atlantic cod have been investigated. Cold shock [−1.7±0.1°C at 20 min post fertilization (PF) for 2 h] was based on a previously developed protocol, and heat shocks, below the lethal threshold of 24°C, were at 16, 18 or 20°C applied 20, 30 or 40 min PF for 20 min. Cold shock did not affect larval survival and was ineffective for producing triploids (range 0–4%). A heat shock of 20°C at 20 min PF generated the highest percentages (range 66–100%) of triploid larvae at hatching, with survival ranging from 10% to 20% relative to the controls. Lower heat shock temperatures or delayed shocks increased survival but decreased the number of triploids, providing no net gain in triploid yield (range 1–9%). Heat shocks applied later than 20 min PF produced 2–4% tetraploid larvae at hatching. A thermal shock of 20°C initiated at 20 min PF and lasting 20 min proved to be the most generally efficient treatment for induction of triploidy in Atlantic cod.  相似文献   

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