大白菜软腐病菌游动性突变体在大白菜体内增殖扩展研究

 用培养皿滤纸吸附测定法和不伤根土壤拌菌处理及针刺接种法,测定了大白菜软腐病菌游动性突变体进入大白菜体内、并在其中侵染定殖和扩展的特性。结果表明,游动性丧失和增强的突变体都可以通过种子萌发和主动接触进入大白菜体内、并可以在体内有短期的繁殖,但菌量远低于野生菌。大白菜叶片接种实验说明,这两种突变体也都可以进行短距离扩展,但扩展距离和菌的繁殖量低于野生菌。     

硫酸铜对泥鳅精子活力的影响

以泥鳅精子为受试材料,应用计算机辅助精子分析系统,研究硫酸铜(0.1、1、10 mg/L)对泥鳅的精子活力的影响.结果表明,在0 h试验组,0.1 mg/L的硫酸铜明显降低泥鳅精子运动速度,1 mg/L的硫酸铜对运动时间和速度产生显著抑制作用,10 mg/L的硫酸铜时运动百分数、运动时间和速度都产生明显影响(P<0.0...     

Single layer centrifugation of stallion spermatozoa consistently selects the most robust spermatozoa from the rest of the ejaculate in a large sample size

Reasons for performing study: An improvement in sperm quality after single layer centrifugation (SLC) has been seen in previous studies using small sample sizes (for example, n = 10 stallions). There is a need to investigate whether this improvement is repeatable over several breeding seasons with a larger number of stallions (n ≥ 30 stallions). Objective: To make a retrospective analysis of the results of SLC performed on more than 250 sperm samples (176 ejaculates) from 31 stallions in 3 consecutive breeding seasons. Methods: Sperm quality (motility, proportion of morphologically normal spermatozoa and the proportion of spermatozoa with undamaged chromatin) was assessed before and after SLC. Results: All parameters of sperm quality examined were significantly better in sperm samples after SLC than in their unselected counterparts (P<0.001 for each parameter). The yield of spermatozoa obtained after SLC was influenced by the type of extender used and also by the concentration of spermatozoa in the original ejaculate, with fewer spermatozoa being recovered when the loading dose contained a high concentration of spermatozoa. The optimal concentration was approximately 100 × 10⁶/ml. Sperm concentration in the samples loaded on to the colloid influenced the sperm yield while the type of semen extender affected sperm quality and survival. Furthermore, the scaled‐up SLC method was found to be suitable for use with a range of ejaculates, with similar sperm kinematics being observed for standard and scaled‐up preparations. Conclusions: SLC consistently improved the quality of stallion sperm samples from a large number of ejaculates. The method could be scaled‐up, allowing larger volumes of ejaculate to be processed easily from a wide range of stallions.     

Sperm production and quality in European eel (Anguilla anguilla) in relation to hormonal treatment

Aquaculture production relies on controlled management of gametogenesis, especially in species where assisted reproduction is needed for obtaining gametes in captivity. The present study used human chorionic gonadotropin (hCG) treatments to induce and sustain spermatogenesis in European eel (Anguilla anguilla). The aim was to evaluate effects of strip-spawning timing (12 vs. 24 hr) after weekly administration of hCG and the necessity of a primer dose (in addition to weekly hormonal treatment) prior to strip spawning (primer vs. no-primer) on sperm quality parameters. Sperm parameters included milt production (weight), density and sperm kinematics at Week 9, 11 and 13 after onset of treatment. Spermiation commenced in 11.5% of males in Week 5 and by Week 9, and all males produced milt. Male weight, milt production, sperm density and spermatocrit did not differ among hormonal treatments during the experimental period. Overall, male weight decreased from 106.3 to 93.0 g, milt weight increased from 3.5 to 5.4 g, sperm density counts decreased from 11.7 × 10⁹ to 10.5 × 10⁹ cells/ml, and spermatocrit decreased from 46.5% to 40.5%. Furthermore, spermatocrit was positively related to haemocytometer counts (R² = .86, p < .001), providing a reliable indicator of sperm density. Differences in sperm kinematics were observed depending on strip-spawning timing after hormonal injection (12 vs. 24 hr) but with no consistent pattern. These sperm quality parameters also did not consistently differ between the no-primer and primer treatments. Considering that each male may be stripped 4–5 times over the 2–3 months spawning season, omitting the primer would reduce animal handling, material costs and labour intensity, while sustaining high-quality sperm production.     

Cryopreservation of silver barb Puntius gonionotus (Bleeker) spermatozoa: effect of extender composition,cryoprotective agents and freezing rate on their postthawing fertilization ability

The effects of extender composition, cryoprotectant concentration and freezing and thawing on the fertilization efficiency of cryopreserved spermatozoa of Puntius gonionotus were evaluated. Computer‐aided motility analysis of semen was conducted to check the suitability of spermatozoa for cryopreservation after mixing with different extenders and cryoprotective agents (CPAs). Extender‐4 with an osmolality 260 mOsmol kg⁻¹and pH 7.6 was used for the cryopreservation study. Among the CPAs, dimethyl sulphoxide (DMSO) was least toxic and more than 60% fertilization was achieved when used at 1.4 M at 0 °C for 10 and 30 min, whereas the toxicity of all CPAs to spermatozoa was evident when tested at 30 °C. Semen frozen at −16 °C min⁻¹ with 1.4 M DMSO showed 70% fertilization, which was significantly higher (P<0.05) than other freezing rates. Samples thawed at 35 °C water showed a fertilization rate comparable with that of fresh semen. Computer‐assisted semen analysis of fresh and frozen semen after thawing showed variations in different types of motility in spermatozoa and in their class. There was no significant difference in motility before or after cryopreservation; however, significant differences could be observed in the average path velocity (VAP), straight line velocity (VSL) and curve linear velocity (VCL). Semen of silver barb could be cryopreserved with extender‐4 by addition of 1.4 M DMSO to a final cryopreservation medium (MED 2) cooled at a rate of −16 °C min⁻¹, stored in liquid nitrogen (−196 °C) and utilized after thawing at 35±2 °C.     

Evaluation of fertilizing capacity of cryopreserved rainbow trout sperm

ABSTRACT:   Experimental insemination was performed using artificially produced low-motility sperm. A mathematical model was applied to the results of the insemination in order to clarify the relationship between sperm motility, the density of sperm and the fertilization rate of eggs. In the model, the probability of fertilization by individual spermatozoa was a function of sperm density in the insemination solution. The results showed that the probability of fertilization clearly decreased with increased sperm density, and the maximum possible fertilizing rate by increasing the sperm density was constrained by the proportion of motile sperm (% motility). The model was also applied to the results of insemination tests of cryopreserved sperm in order to evaluate the fertilizing capacity of cryopreserved sperm. It was proven that cryopreserved sperm needed a higher density to obtain the maximum fertilization rate compared with fresh sperm, and it was anticipated that the ratio of the motile inseminated cryopreserved sperm should be more than 5.0% to achieve an egg fertilization rate greater than 90%.     

哺乳动物精子超微结构研究进展

精子超微结构研究是检验精液品质,揭示精子发生机制,开展受精生物学研究的一项重要内容。从哺乳动物的精子形态结构出发,综述了不同情况下精子变化的特征,论述了国内近些年来在哺乳动物精子超策结构上的一些研究进展,以及开展哺乳动物精子超微结构研究的意义。     

Na+、K+、葡萄糖及甘油对高体雅罗鱼精子活力的影响

[目的]明确水体介质参数与高体雅罗鱼精子活力的关系,解决高体雅罗鱼人工繁殖受精率低及鱼苗鱼种生产效率低的技术难题.[方法]以快速运动时间(FT)、寿命时间(LT)和精子激活率为评价指标,探究Na+、K+、葡萄糖及甘油对高体雅罗鱼精子活力的影响.[结果]Na+浓度为135 mmol/L时高体雅罗鱼精子活力最强,FT为71 s,LT为1020 s,精子激活率为95%;K+浓度为5 mmol/L时高体雅罗鱼精子活力最强,FT为52 s,LT为280 s,精子激活率为80%;葡萄糖浓度为180 mmol/L时高体雅罗鱼精子活力最强,FT为78 s,LT为1200 s,精子激活率为95%;甘油浓度为180 mmol/L时高体雅罗鱼精子活力最强,FT为79 s,LT为1380 s,精子激活率为90%.[结论]适宜浓度的Na+、K+、葡萄糖及甘油具有单独提高高体雅罗鱼精子活力的作用,但高浓度Na+、K+、葡萄糖及甘油对高体雅罗鱼精子的激活率呈明显抑制作用.实际生产中,可选择135 mmol/L Na+、5 mmol/L K+、180 mmol/L葡萄糖或180 mmol/L甘油作为高体雅罗鱼精子的激活液,提高其人工繁殖生产效率.