鱼类解偶联蛋白（UCP）基因研究新进展

通过生理性解偶联调节氧化磷酸化效率可能是进化早期发展起来的一种普遍策略,对生命的存在至关重要. 解偶联蛋白（uncoupling protein,UCP）家族是位于线粒体内膜的转运蛋白,哺乳动物基因组中已发现5个成员,其中UCP1~UCP3紧密相关,而UCP4和UCP5（即BMCP1,brain mitochondrial carrier protein-1）与它们差异较大. UCP1~UCP4不仅在哺乳类、鸟类等恒温脊椎动物中普遍存在,而且在鱼类等变温动物中也被证实存在,但UCP5目前仅在哺乳类中被发现. 哺乳动物褐色脂肪组织的UCP1,介导呼吸链产生的质子梯度泄漏,使氧化产生的能量以热的形式散发,但鱼类等变温动物UCP1的功能尚待进一步研究确立. UCP2和UCP3在产热、控制活性氧生成、脂肪酸氧化以及肥胖、糖尿病的发生中均发挥重要作用,二者的转录调节较复杂. UCP4和UCP5与其他UCP关系较远,UCP4仅在脑中表达,而UCP5在脑中高表达,它们的功能还不十分明确,但研究表明很可能与UCP2和UCP3的功能相似.     

Effects of Dietary Binders on Survival and Growth Performance of Postlarval Tongue Sole, Cynoglossus semilaevis (Günther)

A 30‐d feeding experiment was conducted in tanks to investigate the effects of four different binders (2% in microdiet) on the survival, growth performance, and specific activity of digestive enzymes in tongue sole, Cynoglossus semilaevis Günther, postlarvae (24 d after hatching, with initial average wet weight of 22.4 ± 6.65 mg [mean ± SD]). Five approximately isonitrogenous and isoenergetic microbound diets were formulated with carrageenan (Car), sodium carboxymethylcellulose (CMS), sodium alginate (SA), and gelatin (Gel) as binders, and a diet with no special binder as a control. A commercial diet (RQ Com., manufactured by Marubeni Nisshin Feed Co., Ltd., Chita, Japan) was used as another tested diet, and Artemia nauplii was used as live prey control. The results showed that the survival of the fish fed SA diet (31.3%) was significantly higher than that of fish fed CMS (21.8%), Car (10.8%), and control (21.8%) diets (P < 0.05), but significantly lower than that of the fish fed the live prey (54.5%) diet (P < 0.05). The results of growth followed the similar pattern as that of survival, although there were no significant differences in specific growth rate (SGR) among fish fed SA, CMS, Gel, the control, and RQ diets (7.2, 6.8, 7.0, 6.9, and 7.3% per day; P > 0.05). However, fish fed Car diet had a significantly lower SGR (5.9% per day) than fish fed other diets. Percentages of secreted amylase in fish fed artificial diets were not significantly different, but fish fed artificial diets had significantly higher (P < 0.05) secreted amylase than live prey group. Percentage of secreted trypsin in fish fed SA diet (54.9%) was relatively higher compared with other binders, and not significantly different from RQ Com. and live prey treatments. However, trypsin in fish fed Car diets (29.3%) was significantly lower than in other groups. Specific activities of alkaline phosphatase (AP) in the intestine and AP and leucine aminopeptidase N in brush border membranes in fish fed SA diet (264.6, 1882.8, and 187.2 mU/mg protein) were relatively higher compared with other binders. These results indicate that SA is one of suitable binders compared with carrageenan, CMS, and gelatin in microdiet of postlarval tongue sole.     

Behavioral responses of tilapia (Oreochromis niloticus) to acute fluctuations in dissolved oxygen levels as monitored by computer vision

Behavioral and ventilatory parameters have the possibility of predicting the stress state of fish in vivo and in situ. This paper presents a new image-processing algorithm for quantifying the average swimming speed of a fish school in an aquarium. This method is based on the alteration in projected area caused by the movement of individual fish during frame sequences captured at given time intervals. The image enhancement method increases the contrast between fish and background, and is thus suitable for use in turbid aquaculture water. Behavioral parameters (swimming activity and distribution parameters) and changes in ventilation frequency (VF) of tilapia (Oreochromis niloticus) responded to acute fluctuations in dissolved oxygen (DO) which were monitored continuously in the course of normoxia, falling DO level, maintenance of hypoxia (three levels of 1.5, 0.8 and 0.3 mg l⁻¹) and subsequent recovery to normoxia. These parameters responded sensitively to acute variations in DO level; they displayed significant changes (P < 0.05) during severe hypoxia (0.8 and 0.3 mg l⁻¹ level) compared with normoxic condition, but there was no significant difference under conditions of mild hypoxia (1.5 mg l⁻¹ level). There was no significant difference in VF between two levels of severe hypoxia 0.8 and 0.3 mg l⁻¹ level during the low DO condition. The activity and distribution parameters displayed distinguishable differences between the 0.8 and 0.3 mg l⁻¹ levels. The behavioral parameters are thus capable of distinguishing between different degrees of severe hypoxia, though there were relatively large fluctuations.     

定向交尾技术在中国对虾家系构建中的初步研究

为满足中国对虾家系选育中所需的家系材料,本研究在2004年进行了中国对虾室外和室内定向交尾实验。室外定向交尾实验采用3个不同地理群体的中国对虾,设计了5个交配组合,1尾雄虾搭配4尾雌虾,自然温度下让亲虾交尾,获得了5%的平均交尾率;室内定向交尾实验通过控制水温和密度,促使中国对虾交尾,获得了16.9%的平均交尾率。其中,室内交尾的温度实验设计了12、14、16、18℃4个梯度,雌、雄性别比例均为4∶1,x2检验分析表明,4个温度梯度的交尾率存在差异,其中14℃平均交尾率最高,为31.3%,12℃平均交尾率最低,为6.3%。实验结果表明,室外定向交尾的影响因素较多,不容易控制,很难满足建立大量家系的需要;室内定向交尾在14~16℃的水温条件下,采用雌、雄性别比例为4∶1,可获得较好的交尾效果。本实验结果为大规模建立中国对虾全同胞和半同胞家系奠定了基础,为中国对虾进一步育种工作提供了依据。     

对虾组织膜蛋白制备方法及其多肽组成

选取凡纳缤对虾(Litopenaeus vannamei)的4种组织(鳃、血淋巴、肝胰腺、肌肉)，着重对膜蛋白的提取方法及其多肽组成进行分析。在对虾组织膜蛋白提取过程中，使用了5种蛋白酶抑制剂(苯甲基磺酰氟PMSF、胃酶抑制剂、亮抑酶肽、胰凝乳蛋白酶抑制剂、胰蛋白酶抑制剂)，以减少组织自身的酶将蛋白降解的可能。电镜观察，可见纯度较高的、细胞膜结构卷曲形成的小泡样、封闭的结构。使用Gel-Pro软件对提取产物的SDSPAGE图谱分析，确定了这几种组织的特征多肽分子量分别为75．0kD、70．5kD、26．7kD和71．2kD。     

奥尔森帕金虫环介导等温扩增(LAMP)检测方法的建立及应用

奥尔森帕金虫是重要的贝类病原性寄生虫之一,为建立快速、灵敏、准确和使用简便的检测方法,实验根据奥尔森帕金虫5.8S rDNA中的内转录间隔区(internal transcribedspacer,ITS)序列,建立了环介导等温扩增(loop-mediated isothermal amplification,LAMP)检测方法,并对反应温度、反应体系中Mg2+浓度和反应时间进行了优化。该方法的检测灵敏度约为30拷贝质粒DNA,并且特异性较强,与海水帕金虫、包纳米虫、波豆虫及急性病毒性坏死病毒(acute viral necrosis virus,AVNV)等病原均无交叉反应。使用LAMP法对两批菲律宾蛤仔样品进行检测,结果表明,LAMP检测与传统PCR检测相比,灵敏度更高,检测结果更准确。实验所建立的奥尔森帕金虫LAMP检测方法简单、快速、灵敏且特异性强,可以在沿海贝类养殖厂及条件简陋的实验室使用。     

石菖蒲提取物与化学农药混配对褐飞虱的防治效果

为明确石菖蒲提取物与化学农药混配对褐飞虱的防治作用,研究了石菖蒲提取物与毒死蜱、吡蚜酮和仲丁威3种化学药剂混配网室盆栽条件下的喷雾防治效果。结果表明:石菖蒲提取物与3种化学农药混配,均能达到减少化学农药用量或增加防治效果的作用。25%石菖蒲·毒死蜱乳油1 500倍处理褐飞虱的校正死亡率为93.53%,比对照毒死蜱减少了化学农药用量84.38%;25%石菖蒲·吡蚜酮可湿性粉剂1 200倍处理褐飞虱的校正死亡率为82.67%,与吡蚜酮对照化学农药用量相同,但防治效果显著提高;25%石菖蒲·仲丁威乳油600倍处理褐飞虱的校正死亡率与对照药剂仲丁威的效果接近,但化学农药用量减少了40.0%。     

用NBT还原法检测细菌无细胞溶解物中SOD活性

目的：了解不同细菌无细胞溶解物中ＳＯＤ活性。方法：采用ＮＢＴ还原法检测２株大肠杆菌和８株沙门氏菌（其中７株伤寒沙门氏菌、１株鼠伤寒沙门氏菌）无细胞溶解物中ＳＯＤ活性。结果：２株大肠杆菌ＳＯＤ活性明显低于８株沙门氏菌（Ｐ＜０．０１）;鼠伤寒沙门氏菌ＳＯＤ活性明显高于伤寒沙门氏菌（Ｐ＜０．０１）;而伤寒沙门氏菌Ｌ型返祖株ＳＯＤ活性低于其它株伤寒沙门氏菌（Ｐ＜０．０１）。结论：不同细菌的ＳＯＤ活性有差异;伤寒沙门氏菌Ｌ型返祖株细胞壁的缺陷可能是导致其ＳＯＤ活性降低的原因之一     

烤烟大麦花生一年三熟高效栽培模式及效益分析

介绍了以烤烟为主,烤烟、大麦和花生一年三熟高效栽培模式的主要技术措施和栽培注意事项;并对该模式下的经济效益进行了分析,结果表明：该种植模式下烟农净收入可达29250元/hm2以上,比单作烟叶增收11250元/hm2以上,经济效益和社会效益显著。     

西南地区莪术资源调查及种质收集

对广西、四川、云南和贵州等西南地区的莪术资源进行调查及采集,结果发现,近年来莪术种植区发生较大变化,栽培区域主要分布在广西灵山和四川的崇州、双流、温江;不同地区莪术种质来源复杂、混杂严重,野生种质资源破坏严重,现存数量极少。莪术种植区主要存在农民分散种植、组织化程度相对低,普遍缺乏规范的栽培管理,莪术品种选育工作薄弱等问题。市场疲软、价格走低、产量较低、经济效益差,是莪术栽培面积减少的重要原因。因此,今后应建立莪术良种繁育基地,选育适合栽培的高产优质品种,制定种质、种苗质量标准,加强引种并对种质进行综合评价,从而提高莪术的产量和经济效益。