鱼类microRNA在先天免疫中的研究进展

先天免疫是宿主识别病原及消除病原感染的第一道防线。模式识别受体是参与识别病原入侵的主要分子,主要包括Toll样受体、RIG-I样受体、NOD样受体和C型凝集素受体等。模式识别受体在识别病原相关分子模式后,激活机体的先天免疫信号通路,诱导炎症细胞因子和干扰素的产生,从而启动抵抗病原入侵的免疫应答。越来越多的证据表明,免疫应答的激活、维持和终止受到了严格的调节,使机体在保持一定免疫强度的同时避免产生过度的免疫反应。microRNA是一类长度为18~23 nt的微小非编码RNA,是鱼类先天免疫应答网络中的重要调控因子。近年来,microRNA在鱼类免疫学领域已开展了大量的研究,但缺乏对其进行及时地全面性的总结。本文综述了近年来miRNA在鱼类先天免疫反应中的研究进展,以期为鱼类的分子抗病育种及疾病防控研究提供一些思路。     

鱼类microRNA在先天免疫中的研究进展

先天免疫是宿主识别病原及消除病原感染的第一道防线。模式识别受体是参与识别病原入侵的主要分子,主要包括Toll样受体、RIG-I样受体、NOD样受体和C型凝集素受体等。模式识别受体在识别病原相关分子模式后,激活机体的先天免疫信号通路,诱导炎症细胞因子和干扰素的产生,从而启动抵抗病原入侵的免疫应答。越来越多的证据表明,免疫应答的激活、维持和终止受到了严格的调节,使机体在保持一定免疫强度的同时避免产生过度的免疫反应。microRNA是一类长度为18～23 nt的微小非编码RNA,是鱼类先天免疫应答网络中的重要调控因子。近年来,microRNA在鱼类免疫学领域已开展了大量的研究,但缺乏对其进行及时地全面性的总结。本文综述了近年来miRNA在鱼类先天免疫反应中的研究进展,以期为鱼类的分子抗病育种及疾病防控研究提供一些思路。     

鱼类生长抑素及其受体的研究进展

1973年Brazeau等首先从绵羊下丘脑中分离到生长抑素（somatostatin,简称SS或SRIF）。并发现其具有抑制垂体生长激素释放的功能。随后的研究发现在圆口动物、软骨鱼类、硬骨鱼类、两栖类、爬行类、鸟类、哺乳类等均有生长抑素SS的分布。脊椎动物的多种组织如脑、肠和胰腺等能产生不同类型的SS。现在SS已被确认为一种广泛分布于神经系统和外周组织的多功能肽,具有激素和神经递质双重作用,参与中枢神经系统的生理过程,调节着机体的生长、发育和代谢等多种生理过程。     

耐盐碱鱼类的生理和分子机制研究进展

耐盐碱鱼类生理和分子适应机制的解析,是培育适于中、高碱度盐碱水域增养殖种的先决条件。围绕世界各国适于中、高碱度盐碱湖泊养殖的鱼类代表种,从组织结构的微观调整、血液离子和渗透压调节、特殊氨氮代谢的形成、酸碱调节、激素调节以及基因组特定区域的选择性表达和适应等方面进行归纳总结,提出耐盐碱鱼类的盐碱适应机制具有多样、复杂、系统性强的特点。建议借助先进的基因功能研究方法,系统整合耐盐碱鱼类在生理、表型、行为和各种组学的遗传信息,将相关性探索研究拓展到基因水平的因果关系确定,推动耐碱鱼类的分子遗传基础与分子适应性进化机制的研究进程。     

盐度对鱼类的影响及鱼类的渗透压调节机制

自上世纪50年代末开始,盐度一直是鱼类生理学和实验生物学的重要指标.盐度是影响鱼类生长代谢等各种生理活动的重要环境因素,其变化迫使鱼类自身通过一系列生理变化,来调整体内外渗透压的动态平衡,致使其生长存活与摄食、呼吸代谢、酶和激素水平与胚胎发育等相关生理指标产生相应变化.     

鱼类粘膜免疫研究进展

Fish immunology has achieved great progress in recent years. While before 1990s, most researches focused on the fish systematic immunity, and the mucosal immunity of fish had not been given enough attention. Indeed, it has been shown that fish mucosal immunity plays an important role in disease defense. Fish mucosal immunity research has made some exciting progress in this decade. This review will focus on such progress: Constitution of mucosal-associated tissues and distribution of different immune cells, including T/B lymphocytes, granules, monocytes, macrophages, goblet cells, etc, in these sites have been well described with the development of some monoclonal antibody to these cells and associated techniques. Non-specific immune response mechanism of mucosal tissues reported these years, such as secretion of non-specific anti-bacteria and anti-fungi substances in mucus, the respiratory burst, enzyme activity of immune cells and so on, is believed important for fish disease defense. The specific immunity of mucosal tissues also attracts much interest and makes great achievement in antigen presenting, MHC genes, antibody producing and antibody secreting cells, comparison of serum and mucus immunoglobulin, relationships of immune response between different mucosal immune tissues. Whether mucosal immune system is independent of systematic immune system is another interesting question and causes great concern. In recent years, some evidences from phyletic evolution and ontogenesis show that mucosal immunity is prior to systematic immunity in evolution. Dynamics of antibody producing of mucosal tissues and serum in immersion or oral vaccines immunized fish also shows immune response can be elicited in mucosal tissues independent of systematic immune system. Some researchers also begin to pay attention to factors involved in mucosal immune regulations, for instance, neuromodulators and cytokines. The level of these factors changes in fish immune response process but the mechanisms of regulation still remain unknown. Prospect of the promising future of fish mucosal immunity has also been discussed in this review.     

鱼类雌核发育的研究进展

鱼类雌核发育是在雌核控制下发育的一种重要的单性生殖方式,本文概述了鱼类雌核发育研究的进展情况,主要包括：雌核发育鱼类的特征、染色体组成、细胞学、异精生物学效应及人工诱导鱼类的雌核发育等方面的内容。并对雌核发育在鱼类育种和水产养殖上的应用作了介绍。     

环境激素对鱼类生殖毒性的研究进展

文章综述了水环境激素的种类及其对鱼类生殖毒性的常用的研究方法,并以三丁基锡(TBT)和三苯基锡(TPT)等有机锡污染物为例,详述了环境激素对鱼类生殖毒性的研究进展.研究表明,有机锡化合物会导致鱼类性腺结构和功能受损,生殖行为异常,引起雌鱼雄性化,并产生隔代毒性效应.其毒性机理主要是抑制雌激素合成途径关键酶,干扰雌激素核...     

鱼类生长和营养代谢的激素调控

本文综述了垂体生长激素、类固醇激素、甲状腺激素对鱼类生长中的蛋白质、脂肪、碳水化合物营养代谢的效应,激素在渔业生产的应用前景。     

鱼类免疫应答机制研究进展

鱼类免疫应答可以分为固有免疫和适应性免疫,但固有免疫发挥主要作用。固有免疫对病原体的识别是通过模式识别受体PRR与病原相关分子模式PAMP的相互结合实现,这与哺乳类相似。但为适应水生生活,鱼类固有免疫对PAMP的识别范围更广,免疫应答的启动条件更低。固有免疫的效应细胞主要是单核/巨噬细胞、嗜中性粒细胞、自然杀伤细胞等,具有吞噬和杀伤功能,还可分泌多种免疫相关的细胞因子,介导发生炎症反应。适应性免疫中,T淋巴细胞通过抗原提呈细胞分解吸收抗原,由主要组织相容性复合物(MHC)类分子递送到细胞表面才能识别。B淋巴细胞分泌产生以免疫球蛋白Ig M为主的抗体分子,而发挥抗体中和作用及免疫调理作用的Ig G在鱼类中比较少见,说明鱼类抗体的免疫功能还处于较低水平。本文综述了近二十年内鱼类免疫应答机制的相关研究进展,为进一步了解鱼类免疫应答机制提供参考。     

高不饱和脂肪酸（HUFAs）在淡水鱼类中的营养作用研究进展

鱼粉、鱼油资源的短缺促使全球水产养殖业积极寻找其替代原料,而探究鱼粉、鱼油与其替代物之间的差异尤为重要,其中最主要的差异就是高不饱和脂肪酸(highly unsaturated fatty acids,HUFAs)是否存在及其含量多少。HUFAs是一类碳原子数目≥20、双键数≥3的脂肪酸,具有为动物提供能量、构成细胞膜组分、形成高生物活性物质、调控脂质代谢和免疫功能等重要作用,主要存在于鱼油和某些类别的微藻中。淡水鱼类具备自身合成HUFAs的能力,因此,一般认为HUFAs不是淡水鱼类的必需脂肪酸,无需通过饲料提供。但已有研究指出,饲料中添加一定量的HUFAs能够对淡水鱼类产生积极的营养作用,表明淡水鱼类的脂肪酸营养理论尚需进一步完善。本文综述了HUFAs在淡水鱼类生长、脂质代谢、健康免疫、繁殖特性等方面发挥作用的相关研究结果,明确提出淡水鱼类需要摄取一定水平的外源性HUFAs,指出在当前淡水鱼饲料中普遍使用HUFAs相对缺乏的蛋白源和油脂源的背景之下,HUFAs对淡水鱼类的作用应受到关注。最后,本文对今后淡水鱼类HUFAs营养的研究方向,以及新的HUFAs油脂源的开发前景进行了展望。     

Endocrinology and fish culture

In the current practice of fish culture the use of hormones is mainly limited to the field of reproduction, and more precisely to induce or synchronize ovulation and stimulate spermiation. The practice of pituitary homogenates injection (called hypophysation) which started in the early 1930's has allowed spectacular developments in the culture of some cyprinid species, especially in China, India and Europe. HCG has been used successfully in a limited number of species and LHRH-A, often associated with antidopaminergic compounds, started to be used in some species, especially cyprinids, on a commercial scale. Sex steroids are now commonly used to reverse the sex of some species in salmonids, cyprinids, tilapias. Due to legal restriction and consumer opposition, the tendency is to limit the use of steroids, especially in fish which are later offered to consumption. GH, which significantly stimulates growth and reduces the food conversion rate in laboratory experiments, will possibly be used on a large scale in fish farms. Endocrinology has considerably increased the knowledge of the mechanisms controlling some physiological functions; this has allowed the identification of sensitive phases in fish in captivity, and helps in the management and the process of domestication (most of the cultured fish species have been taken form the wild recently).     

南美白对虾亲虾的培育与管理

为探究花生四烯酸 (ARA)对凡纳对虾亲本繁殖、免疫及脂质代谢的影响,实验根据实际亲虾培育与幼体生产模式,选取6月龄,大小规格一致的雄虾与单侧眼柄切除的雌虾,随机分为5组,雌雄分开养殖,分别投喂含有不同含量ARA (0.03%、2.70%、4.99%、10.63%)的软颗粒饲料 (分别命名为Z1~Z4组)与纯生物饵料 (沙蚕)的生产组 (Z5)。结果显示,摄食饲料的雌虾增重率 (WGR)比生产组显著提升,亲本肝胰腺指数 (HSI)随着ARA含量的增加呈现先升后降的整体趋势,在4.99% ARA影响下亲本肝胰腺发育良好,孵化率最高,幼体产量最多质量最好,且卵巢发育相关基因 (Vtg、VtgR、VASA与FAMeT2)表达最高;4.99% ARA添加量还可影响雌虾肝胰腺脂质代谢水平,提高脂质利用与转运相关基因 (PL、SREPB与FATB)表达,进而影响受精卵中脂肪酸成分变化,显著增加功能性脂肪酸DHA含量,同时影响其中∑n-3 PUFA与∑n-6 PUFA含量及其之间比值。因繁殖与免疫的拮抗关系,造成该ARA含量下抗氧化应激与非特异免疫水平下降。研究表明,饲料中添加不同ARA能够影响凡纳对虾亲本生长与繁殖、免疫及脂质代谢能力,在优先考虑繁殖性能下,建议在亲虾饲料中保持4.99% ARA更能促进卵巢发育与幼体生产。

     

Effect of combined fish meal : soybean meal ratio,vitamin C and fish oil supplementations in diet on the growth and reproduction of red swamp crayfish,Procambarus clarkii (Crustacea: Decapoda)

Fish meal (FM), vitamin C (VC) and fish oil (FO) play important roles in the growth and reproduction in aquatic animals. To determine the optimum dietary combinations of FM:SM (soybean meal) ratio, VC and FO supplementations for the growth and reproduction of female crayfish Procambarus clarkii, we used the L9 (3³) orthogonal array, which arranged three factors varied at three levels (FM:SM at 1:3, 1:2 and 1:1.5; VC supplementation at 0.02%, 0.04% and 0.06%; FO inclusion at 1.90%, 2.85% and 3.80%). Range analysis showed that the highest weight gain (WG) of the crayfish occurred at FM:SM of 1:1.5, VC supplementation of 0.04% and FO inclusion of 1.90%, and the maximum gonadosomatic index (GSI), egg laying amount (ELA) and spawning rate (SR) were obtained at FM:SM 1:1.5, VC supplementation 0.06% and FO inclusion 3.80%. Analysis of variance indicated that all the three factors had no significant effects on WG. Fish oil supplementation significantly affected GSI, ELA and SR (P<0.05), while FM:SM did not significantly influence any of these indicators. Taking the cost into consideration, we suggest that a dietary FM:SM of 1:3, VC supplementation 0.06% and FO inclusion 3.80% might be the optimal combinations for the reproduction of P. clarkii.