鱼类生殖细胞移植技术的发展及应用前景

鱼类生殖细胞移植技术是通过诱导不同物种之间生殖系嵌合体来实现。原始生殖细胞和精原细胞(或卵原细胞)是诱导生殖细胞系嵌合体的关键材料。在过去的十多年中,通过采用不同的供体生殖细胞和不同发育阶段(囊胚期胚胎、初孵仔鱼和成鱼)的鱼为受体,开发出多种鱼类生殖细胞移植技术。这些成果的取得,为生殖细胞移植技术应用于诸多水产养殖新兴领域打下了坚实基础。该技术可以应用于:(1)生殖细胞生物学和转基因鱼等基础研究;(2)遗传资源和濒危鱼种的保护;(3)鱼类性别选择育种;(4)有效提高放流鱼苗的遗传多样性。     

鱼类原始生殖细胞发育与生殖操作技术研究进展

原始生殖细胞是胚胎发育过程中最早建立的一群生殖干细胞,是有性生殖动物生殖发育的基础。鱼类原始生殖细胞特化遵循“先成论”的模式,早期胚胎发育过程中获得母源生殖质组分的细胞特化为原始生殖细胞,特化形成的原始生殖细胞需要维持其生殖干细胞命运,并经过长距离迁移最终到达性腺原基的位置。原始生殖细胞特化、迁移和命运维持过程受到多种基因和信号通路的综合调控。研究鱼类原始生殖细胞发育不仅有助于深入理解脊椎动物细胞特化、迁移和命运维持等基本生物学过程的调控机理,而且是开发新的养殖鱼类生殖控制和生殖干细胞移植技术的重要基础。本文概述了鱼类原始生殖细胞发育的基础理论以及生殖操作技术研究进展,并展望了未来的发展趋势,以期为开发重要养殖鱼类优良种质创制新技术提供参考。     

显微注射技术在制备鱼类嵌合体和转基因海水鱼上的应用

以鱼类胚胎细胞和胚胎干细胞为核供体进行细胞移植构建鱼类嵌合体研究方面,现有的成功报道均采用显微注射方法;在转基因海水鱼类研究中,显微注射也是最为常用的技术,本实验室在花鲈胚胎干细胞嵌合体构建和外源基因向花鲈胚胎的转移研究中取得的结果也充分证实,显微注射技术是开展海水鱼类细胞移植和转基因研究的首选技术。     

鱼类细胞核移植研究进展及前景展望

细胞核移植技术是目前生物技术领域研究的热点之一,其科学意义和应用价值重大。本文介绍了中国和世界上鱼类细胞核移植的研究成果及其最新进展;综述了鱼类细胞核移植的基本程序、方法和影响因素,包括胞质受体的准备、核供体的制备、核移植和核质杂种的培养。并对鱼类细胞核移植的应用、现存问题及应用前景进行了讨论。     

水电开发背景下长江上游保护区珍稀特有鱼类保护实践

鉴于金沙江下游水电工程可能对“长江上游珍稀特有鱼类国家级自然保护区”产生的生态影响,规划由中国长江三峡集团公司投资3.82亿元用于保护区的生态补偿。截至2013年底,各项工作均已按计划落实并取得显著成果。科学研究方面,已从“珍稀特有鱼类生活史和人工繁殖技术”、“保护区环境因子变动特征及其对鱼类的影响”、“鱼类保护生物学与保护效果评估研究”、“水利工程建设与鱼类保护协调发展对策研究”四个方面开展了一系列科研项目,并在几种特有鱼类人工繁殖方面取得重要突破。增殖放流方面,完成3个鱼类增殖放流站的建设,仅向家坝放流站就已累计放流珍稀特有鱼类72万尾。水生态监测方面,自2006年起每年开展保护区水生态系统尤其是鱼类资源的监测工作,8年间共监测到达氏鲟和胭脂鱼2种珍稀鱼类及46种特有鱼类。金沙江下游二期水电工程阶段,三峡集团计划进一步加强投入,在开展长期监测的基础上,因地制宜地制定和推行符合该保护区特点的适应性管理对策,促进水电开发与生态保护协调发展。     

长江上游珍稀特有鱼类保护区鱼类生境特征初步研究

长江上游珍稀特有鱼类保护区是我国最长的河流型自然保护区,保护了多种珍稀特有鱼类,具有重大的生物多样性保护价值。随着金沙江梯级开发的实施,长江上游保护区鱼类栖息条件将受到不同程度的影响。本研究基于长江上游珍稀特有鱼类保护区的地形、地貌、水文、水动力等条件,提出了保护区鱼类生境特征表征指标体系,并根据该指标体系初步分析了保护区栖息地生境特征。研究结果可为长江上游珍稀特有鱼类保护区鱼类资源保护措施的制定提供参考依据。     

云南珍稀野生土著鱼类丝尾鲮人工养殖获成功

经过云南省渔业科学研究院等单位联合攻关，云南省珍稀野生土著鱼类——丝尾蠖人工养殖获成功并在红河、文山等地实现池塘养殖。此举不但保护了云南省珍稀土著鱼类；也为开发特色水产养殖打下了基础。“土著丝尾蠖池塘养殖技术研究与推广项目≯专家组鉴定认为，该研究成果整体技术达到国内同类研究先进水平。     

鱼类遗传改良研究综述

本文对全世界范围内鱼类遗传改良研究的概况及其有关问题进行了全面的介绍和评述,从选择育种、杂交育种、性别控制、多倍体诱导、细胞核移植和细胞融合、低温保存技术、DNA分子标记育种、转基因技术等方面系统介绍了鱼类遗传改良的方法、在水产养殖中的应用和已取得的成就,并对鱼类遗传改良今后的发展趋势进行了展望,旨在为今后进一步开展鱼类遗传改良研究提供参考。     

草鱼、青鱼体外培养细胞的属间、亚科间核移植

自King和Briggs 1952年首次报道了细胞核移植在两栖类上获得成功以来,这项卓绝的技术引起国内外学者的极大重视和兴趣,并逐渐应用到两栖类以外的其它动物。在我国,童第周教授等1963年首次应用此项技术于鱼类。他们在金鱼和鳑鮍鱼上的开拓性实验,证明鱼类细胞核同样可以进行核移植。七十年代起,我国在鱼类细胞核移植方面的研究得到迅速发展,并逐渐以理论研究走向实际应用。在鲫、鲤,鲢、草鱼、团头鲂等鱼类上进行研究,得到了几个不同组合的移核鱼或胚胎,其中某些移核杂交鱼是可育的。为了进行鱼类遗传改良研究,作者在草鱼、青鱼、团头鲂上着手进行了细胞核的移植,利用体外长期培养的体细胞作供体,在属间和亚科间鱼类上作移核实验,得到了不同发育期的胚胎。现将此工作作简要报道。     

基于鱼类资源调查的增殖放流方案前期研究-以扎敦水利枢纽为例

进行扎敦枢纽鱼类增殖放流方案设计，为科学开展水利水电工程鱼类增殖放流提供理论依据和技术支撑。2019年10月和2020年4―5月，对呼伦贝尔市扎敦河鱼类资源开展2次系统调查，在此基础上综合分析确定增殖放流的种类，并对放流规模、时间、地点、周期及时序等放流方案进行规、划设计。结果表明，扎敦河共分布有16种鱼类，隶属于2纲5目8科15属。其中，珍稀保护鱼类4种，占总种数的25%。现场调查共采集到鱼类13种，共计2 899尾，重37 188.9 g。参考生物完整性指数(IBI)，通过对保护地位、经济价值、洄游习性、种群资源量、受工程影响程度及人工繁育技术是否突破等6方面综合分析，将细鳞鲑Brachymystax lenok、哲罗鲑Hucho taimen、黑龙江茴鱼Thymallus grubii、瓦氏雅罗鱼Leuciscus waleckii、黑斑狗鱼Esox reichertii、江鳕Lota lota等6种珍稀保护、重要经济鱼类作为本工程近期放流对象。将东北七鳃鳗Lampetra morii作为远期放流对象，近期主要开展人工驯养、繁育技术和栖息地保护研究。基于类比分析，推荐放流数量为16万尾/年。     

Germ cell transplantation as a potential biotechnological approach to fish reproduction

Although the use of germ cell transplantation has been relatively well established in mammals, the technique has only been adapted for use in fish after entering the 2000s. During the last decade, several different approaches have been developed for germ cell transplantation in fish using recipients of various ages and life stages, such as blastula-stage embryos, newly hatched larvae and sexually mature specimens. As germ cells can develop into live organisms through maturation and fertilization processes, germ cell transplantation in fish has opened up new avenues of research in reproductive biotechnology and aquaculture. For instance, the use of xenotransplantation in fish has lead to advances in the conservation of endangered species and the production of commercially valuable fish using surrogated recipients. Further, this could also facilitate the engineering of transgenic fish. However, as is the case with mammals, knowledge regarding the basic biology and physiology of germline stem cells in fish remains incomplete, imposing a considerable limitation on the application of germ cell transplantation in fish. Furthering our understanding of germline stem cells would contribute significantly to advances regarding germ cell transplantation in fish.     

Interspecific germ cell transplantation: a new light in the conservation of valuable Balkan trout genetic resources?

Interspecific transplantation of germ cells from the brown trout Salmo trutta m. fario and the European grayling Thymallus thymallus into rainbow trout Oncorhynchus mykiss recipients was carried out in order to improve current practices in conservation of genetic resources of endangered salmonid species in the Balkan Peninsula. Current conservation methods mainly include in situ efforts such as the maintenance of purebred individuals in isolated streams and restocking with purebred fingerlings; however, additional ex situ strategies such as surrogate production are needed. Steps required for transplantation such as isolation of high number of viable germ cells and fluorescent labeling of germ cells which are to be transplanted have been optimized. Isolated and labeled brown trout and grayling germ cells were intraperitoneally transplanted into 3 to 5 days post hatch rainbow trout larvae. Survival of the injected larvae was comparable to the controls. Sixty days after transplantation, fluorescently labeled donor cells were detected within the recipient gonads indicating successful incorporation of germ cells (brown trout spermatogonia and oogonia—27%; grayling spermatogonia—28%; grayling oogonia—23%). PCR amplification of donor mtDNA CR fragments within the recipient gonads additionally corroborated the success of incorporation. Overall, the transplantation method demonstrated in this study presents the first step and a possible onset of the application of the germ cell transplantation technology in conservation and revitalization of genetic resources of endangered and endemic species or populations of salmonid fish and thus give rise to new or improved management strategies for such species.     

Biotechnology applied to fish reproduction: tools for conservation

This review discusses the new biotechnological tools that are arising and promising for conservation and enhancement of fish production, mainly regarding the endangered and the most economically important species. Two main techniques, in particular, are available to avoid extinction of endangered fish species and to improve the production of commercial species. Germ cell transplantation technology includes a number of approaches that have been studied, such as the transplantation of embryo-to-embryo blastomere, embryo-to-embryo differentiated PGC, larvae to larvae and embryo differentiated PGC, transplantation of spermatogonia from adult to larvae or between adults, and oogonia transplantation. However, the success of germ cell transplantation relies on the prior sterilization of fish, which can be performed at different stages of fish species development by means of several protocols that have been tested in order to achieve the best approach to produce a sterile fish. Among them, fish hybridization and triploidization, germline gene knockdown, hyperthermia, and chemical treatment deserve attention based on important results achieved thus far. This review currently used technologies and knowledge about surrogate technology and fish sterilization, discussing the stronger and the weaker points of each approach.     

Colonization,proliferation, and survival of intraperitoneally transplanted yellowtail <Emphasis Type="Italic">Seriola quinqueradiata</Emphasis> spermatogonia in nibe croaker <Emphasis Type="Italic">Nibea mitsukurii</Emphasis> recipient

Recently, we developed an intraspecies spermatogonial transplantation technique in a pelagic egg spawning marine teleost, nibe croaker Nibea mitsukurii. Nibe croaker is an ideal candidate recipient for spermatogonial transplantation since it has a short generation time and small body size. In the present study, yellowtail Seriola quinqueradiata spermatogonia were transplanted into nibe croaker larvae, and the behavior of transplanted spermatogonia in recipient gonads was observed. Three weeks post-transplantation, yellowtail spermatogonia were incorporated into the gonads of 72 out of 88 recipients. An antiproliferating cell nuclear antigen was detected in incorporated yellowtail spermatogonia, suggesting that the xenogenic germ cells were proliferating in recipient gonads. Yellowtail vasa-positive spermatogonia survived for 11 months after transplantation in the gonads of recipient fish. Thus, we showed that the microenvironment in nibe croaker gonads can support the colonization, proliferation, and survival of germ cells derived from a different taxonomic family.     

Application of surrogate broodstock technology in aquaculture

Fisheries Science - Surrogate broodstock technology facilitates the production of donor-derived gametes in surrogates, and comprises transplanting germ cells of a donor into recipients of a...     

Fin cell cryopreservation and fish reconstruction by nuclear transfer stand as promising technologies for preservation of finfish genetic resources

Domestication is a long-term process during which wild fish are acclimated to farming conditions and hopefully are reproduced over several generations, possibly using selective breeding. Preservation of the genetic diversity of the original population, together with that of the ongoing selection steps, is important for ecological and economical purposes. Cryobanking of reproductive cells is one answer to meet this need. In fish, however, only sperm can be cryopreserved as neither oocytes nor embryos are capable of handling the freeze-thawing stress. In this review, we explore to what extent diploid cells obtained from fin pieces can be used for the preservation of both parental genomes. The main parameters, which should be under control to ensure proper production of fin cells in culture and to enable cryopreservation of the material are described. After cryobanking of such non-reproductive cells, fish can be reconstructed using the nuclear transfer technology whose potentials and difficulties are discussed. The gametes produced by the fish reconstructed after somatic cells nuclear transfer are different to some extent from the gametes obtained after the direct transplantation of primordial germ cell or spermatogonial germ cells into host embryos or larvae. However, in some cases, only somatic cells can be obtained in quantities which would be compatible with strain restoration purposes. From the knowledge available today, it is reasonable to expect that nuclear transfer becomes available for fish reconstruction, even if restricted to high-tech biotechnology facilities. Therefore, cryobanking of fin somatic cells can be farsightedly considered for high-throughput diploid genome conservation.     

西藏渔业资源保护现状、问题及对策

本文分析西藏地区渔业资源保护现状。针对西藏地区渔业资源所面临的各种生态和社会问题,提出相应的保护对策。这些对策包括对部分珍稀濒危鱼种实行迁地保护,加强种质资源保护,建立珍稀特有水产的专项或综合保护区,建立珍稀特有鱼类资源的环境监测体系。另外,经济发展与环境保护并重,加强科研和宣教工作,保护珍稀濒危物种的现有生境,防止外来物种入侵,发展可持续性渔业生产。