Norwegian University of Life Sciences, Faculty of Veterinary Medicine, Oslo, Norway.
Adv Exp Med Biol. 2019;1200:187-224. doi: 10.1007/978-3-030-23633-5_7.
The teleost fishes are the largest and most diverse vertebrate group, accounting for nearly half of all known vertebrate species. Teleost fish exhibit greater species diversity than any other group of vertebrates and this is reflected in the unique variety of different reproductive strategies displayed by fish. Fish have always been an important resource for humans worldwide, especially as food. While wild capture fisheries have historically been the main source of fish, the farming of fish (aquaculture) is increasingly becoming the more dominant source of food fish, and is predicted to account for 60% of total global fish production by 2030.Fishes are increasingly threatened by a wide range of anthropogenic impacts, including loss of habitat, pollution, invasive species and over-exploitation. In addition, climate change, especially the consequences of global warming, can impact fish at all levels of biological organization from the individual to the population level, influencing both physiological and ecological processes in a variety of direct and indirect ways. As such, there is an urgent need to protect and conserve the huge genetic diversity offered by this diverse vertebrate group, not just as a source of genes for contemporary breeding and for protection against the consequences of climate change and disease, but also as part of our national heritage. While the cryopreservation of reproductive cells is a means of achieving these objectives, currently only fish sperm can be successfully frozen. Due to their large size, large yolk compartment, low membrane permeability and high chilling sensitivity, successful and reproducible protocols for the cryopreservation of fish oocytes and embryos still remains elusive. However, significant advances have been made in the cryopreservation of primordial germ cells as an alternative means of conserving both paternal and maternal genomes. Although more research needs to be carried out on how these cells can be optimally applied to emerging reproductive technologies, including transplantation techniques and surrogate broodstock technologies, the successful cryopreservation of fish germ cells, and the establishment of genetic resource banks, offers the possibility of both conserving and restoring threatened species. Further, current and future conservation efforts need to consider the impact of climate change in both in situ conservation and reintroduction efforts.In conclusion, it is anticipated that the successful cryopreservation of fish germplasm will result in a range of economic, ecological and societal benefits. In partnership with emerging assisted reproductive technologies, the successful cryopreservation of fish germplasm will lead to more efficient reproduction in aquaculture, assist selective breeding programmes, and be of crucial importance to future species conservation actions.
硬骨鱼类是最大和最多样化的脊椎动物群体，占所有已知脊椎动物物种的近一半。硬骨鱼类的物种多样性超过任何其他脊椎动物群体，这反映在鱼类所展示的独特多样的生殖策略上。鱼类一直是全世界人类的重要资源，尤其是作为食物。虽然野生捕捞渔业一直是鱼类的主要来源，但鱼类养殖（水产养殖）越来越成为鱼类食品的主要来源，预计到 2030 年，将占全球鱼类总产量的 60%。鱼类受到广泛的人为影响的威胁，包括栖息地丧失、污染、入侵物种和过度捕捞。此外，气候变化，特别是全球变暖的后果，可以在从个体到种群水平的各个生物学组织层面影响鱼类，以各种直接和间接的方式影响生理和生态过程。因此，迫切需要保护和保存这个多样化的脊椎动物群体所提供的巨大遗传多样性，不仅作为当代繁殖的基因来源，以保护鱼类免受气候变化和疾病的影响，而且作为我们国家遗产的一部分。虽然生殖细胞的冷冻保存是实现这些目标的一种手段，但目前只有鱼类精子可以成功冷冻。由于其体型大、卵黄体积大、膜通透性低、冷却敏感性高，鱼类卵母细胞和胚胎的成功且可重复的冷冻保存方案仍然难以实现。然而，在作为保护父本和母本基因组的替代方法的原始生殖细胞的冷冻保存方面已经取得了重大进展。尽管需要进一步研究如何将这些细胞最优化地应用于新兴的生殖技术，包括移植技术和代孕亲鱼技术，但鱼类生殖细胞的成功冷冻保存和遗传资源库的建立，为保护和恢复濒危物种提供了可能。此外，当前和未来的保护工作需要考虑到气候变化对就地保护和再引入工作的影响。总之，预计鱼类种质的成功冷冻保存将带来一系列经济、生态和社会效益。与新兴的辅助生殖技术相结合，鱼类种质的成功冷冻保存将导致水产养殖更高效的繁殖，有助于选择性繁殖计划，并对未来的物种保护行动至关重要。
