太平洋牡蛎人工育苗稳产高产技术的探讨

本文从水的处理，单胞藻选择，亲贝选择与蓄养，洗卵和及时选幼．幼虫培育期间的筛选．附着基处理及投附着基后的管理，脱苗的预防等方面进行了牡蛎人工育苗技术的研究探讨，以提高牡蛎育苗的成功率和单位水体的出苗量．使太平洋牡蛎育苗能稳产高产。     

两种海洋贝类多糖的提取及其生物活性评价

[目的]提取翡翠贻贝多糖和牡蛎多糖并评价其生物活性,为这两种贝类多糖的开发利用提供科学依据.[方法]采用酶解法提取翡翠贻贝多糖和牡蛎多糖,并采用苯酚—硫酸比色法测定其多糖中的总糖含量;通过纸片扩散法、清除羟基自由基(·OH)试验和MTT法分别评价两种多糖的体外抑菌活性、抗氧化活性及抗猪蓝耳病毒(PRRSV)活性.[结果]翡翠贻贝多糖和牡蛎多糖提取率分别为0.21％和0.14％,其多糖中的总糖含量分别为90.2％和90.1％.翡翠贻贝多糖和牡蛎多糖对·OH均有一定的清除作用,且随多糖质量浓度的增加而逐渐增强;对金黄色葡萄球菌和大肠杆菌均无明显的抑制作用;对PRRSV均无明显的阻断、抑制及直接杀灭作用.[结论]翡翠贻贝多糖和牡蛎多糖均具有一定的抗氧化活性,但不显示有意义的体外抑菌和抗PRRSV活性,可将其作为抗氧化剂资源予以研究.     

Isolation and characterization of microsatellite DNA markers in endangered Mekong giant catfish Pangasianodon gigas

ABSTRACT:   The Mekong giant catfish is one of the largest freshwater fish in the world, and is endemic to the Mekong basin. Recently, the number of Mekong giant catfish has drastically decreased. In this study, seven microsatellite DNA markers of the Mekong giant catfish were developed for evaluation of the species' genetic diversity. Mendelian inheritance of four of seven markers was confirmed using offspring (F1) produced from one pair. Number of alleles per locus in the founder population ranged 1–4 with a mean of 2.8, and that in F1 ranged 1–2 with a mean of 1.6. The expected heterozygosity in the founder population ranged 0–0.66 with a mean of 0.38, and that in F1 ranged 0–0.5 with a mean of 0.28. The mean expected heterozygosity in the founder population is apparently lower than that in Pangasius bocourti and other freshwater species, but higher than that in endangered species. In the future, the microsatellite data in this study will be used in minimal kinship approaches, because these individuals constitute the basic seed for release into wild in an effort to conserve the native population of Mekong giant catfish.     

长牡蛎非整倍体的制备、胚胎发育及存活能力

通过二倍体、三倍体杂交的方法制备长牡蛎(Crassostreagigas)非整倍体。实验组设为2n♀×3n♂组、3n♀×2n♂组和3n×3n组,对照组为2n×2n组。与对照组相比,实验组畸形率高,担轮虫孵化率及D形幼虫生成率等参数均降低,幼虫死亡率高。在担轮幼虫向D形幼虫转化期,实验组发育滞后。培育过程中染色体数为25左右的非整倍体不能存活,整倍体和染色体数与整倍体接近的非整倍体能够存活。实验证实该方法是进行贝类非整倍体制备的有效手段。     

Distribution of Tetrodotoxin in Pacific Oysters (Crassostrea gigas)

A potent and heat-stable tetrodotoxin (TTX) has been found to accumulate in various marine bivalve species, including Pacific oysters (Crassostrea gigas), raising a food safety concern. While several studies on geographical occurrence of TTX have been conducted, there is a lack of knowledge about the distribution of the toxin within and between bivalves. We, therefore, measured TTX in the whole flesh, mantle, gills, labial palps, digestive gland, adductor muscle and intravalvular fluid of C. gigas using liquid chromatography-tandem mass spectrometry. Weekly monitoring during summer months revealed the highest TTX concentrations in the digestive gland (up to 242 µg/kg), significantly higher than in other oyster tissues. Intra-population variability of TTX, measured in the whole flesh of each of twenty animals, reached 46% and 32% in the two separate batches, respectively. In addition, an inter-population study was conducted to compare TTX levels at four locations within the oyster production area. TTX concentrations in the whole flesh varied significantly between some of these locations, which was unexplained by the differences in weight of flesh. This is the first study examining TTX distribution in C. gigas and the first confirmation of the preferential accumulation of TTX in oyster digestive gland.     

长牡蛎精子膜蛋白的提取及其部分生化性质的研究

从提取时间和TritonX-100浓度两个方面对长牡蛎(Crassosstrea gigas)精子膜蛋白提取条件进行优化,确定最佳提取条件:将精液150 g离心去除精原细胞,经PBS缓冲液和Tris-HCl缓冲液清洗后,3 000 g离心10 min(4 ℃)得精子悬液;然后加入3倍体积含1% TritonX-100的膜蛋白提取液,冰浴振摇1 h;50 000 g离心15 min(4 ℃),收集上清液即为精子膜蛋白溶液.SDS-PAGE电泳后,考马斯亮蓝R-250染色检测到21种膜蛋白,分子量在26～156 kD之间,PAS染色检测到糖蛋白有14种,苏丹黑B染色检测到脂蛋白有17种,其中有13种膜蛋白既是糖蛋白又是脂蛋白.实验结果还发现1种分子量为38 kD的r16膜蛋白既为糖蛋白又为脂蛋白,且高碘酸-Shiff试剂和苏丹黑B染色最深,条带最清晰,蛋白丰度最高,与此相对的分子量为55 kD的r12膜蛋白,考马斯亮蓝R-250染色也较深,条带清晰,但其糖蛋白和脂蛋白染色相对r16膜蛋白较浅,说明r16和r12两种膜蛋白其蛋白丰度相差不大,其糖基化程度及脂化程度可能相差较大,此两种膜蛋白有待于进一步分离纯化.此研究结果可为长牡蛎精子膜蛋白在精子发生和受精过程中作用的研究提供基础资料.     

大瓶螺四种同工酶的电泳分析

大瓶螺四种同工酶的电泳分析李清漪，刘堰（西南师范大学生物系，重庆６３０７１５）关键词大瓶螺，同工酶，差异，电泳分析ＴＨＥＥＬＥＣＴＲＯＰＨＯＲＥＴＩＣＡＮＡＬＹＳＩＳＯＦ４ＩＳＯＥＮＺＹＭＥＳＯＦＡＭＰＵＬＬＡＲＩＡＧＩＧＡＳ￥ＬｉＱｉｎｇｙｉａｎｄ...     

杨圆蚧天敌昆虫的初步研究

本文记述了杨圆蚧(Quadraspidiotus gigas Thiem et Gerneck)的天敌昆虫种类,并对其生活习性进行了初步观察,对其利用价值进行了分析,对天敌的利用途径进行了探索.     

太平洋牡蛎生理活动的季节变化

以大窑湾养殖太平洋牡蛎离体鳃为材料,周年观察鳃片的匍匐速度以及鳃片在不同盐度海水中和无氧状态下的耐受力。以此作为生理活动指标,描述了其季节变化。显示繁殖季节牡蛎的生理活动下降。同时发现本海区牡蛎鳃缘附有大量真枝螅,对牡蛎鳃纤毛的活动和生长有一定影响。     

添加剂对秘鲁鱿鱼肌原纤维蛋白热诱导凝胶特性的影响

为探讨添加剂及其添加量对秘鲁鱿鱼肌原纤维蛋白热诱导凝胶特性的影响,以秘鲁鱿鱼为原料,在单因素试验基础上选择4种添加剂(壳聚糖、转谷氨酰胺酶、卡拉胶、海藻酸钠),通过响应面法建立肌原纤维蛋白凝胶硬度和添加剂用量之间的响应模型。结果表明,4种添加剂的最适添加量分别为:壳聚糖0.40%、转谷氨酰胺酶0.50%、卡拉胶0.90%、海藻酸钠0.25%,在此条件下秘鲁鱿鱼肌原纤维蛋白热诱导凝胶硬度达最大值859.85 g,保水性为96.34%。此复合添加剂能显著改善秘鲁鱿鱼肌原纤维蛋白的凝胶特性。研究结果为生产高品质的秘鲁鱿鱼凝胶制品提供了理论依据。