School of Environmental and Life Sciences, University of Newcastle, Newcastle, NSW, Australia.
Department of Biology, University of Ottawa, Ottawa, ON, Canada.
Adv Exp Med Biol. 2019;1200:413-463. doi: 10.1007/978-3-030-23633-5_14.
Amphibians have experienced a catastrophic decline since the 1980s driven by disease, habitat loss, and impacts of invasive species and face ongoing threats from climate change. About 40% of extant amphibians are under threat of extinction and about 200 species have disappeared completely. Reproductive technologies and biobanking of cryopreserved materials offer technologies that could increase the efficiency and effectiveness of conservation programs involving management of captive breeding and wild populations through reduced costs, better genetic management and reduced risk of species extinctions. However, there are relatively few examples of applications of these technologies in practice in on-the-ground conservation programs, and no example that we know of where genetic diversity has been restored to a threatened amphibian species in captive breeding or in wild populations using cryopreserved genetic material. This gap in the application of technology to conservation programs needs to be addressed if assisted reproductive technologies (ARTs) and biobanking are to realise their potential in amphibian conservation. We review successful technologies including non-invasive gamete collection, IVF and sperm cryopreservation that work well enough to be applied to many current conservation programs. We consider new advances in technology (vitrification and laser warming) of cryopreservation of aquatic embryos of fish and some marine invertebrates that may help us to overcome factors limiting amphibian oocyte and embryo cryopreservation. Finally, we address two case studies that illustrate the urgent need and the opportunity to implement immediately ARTs, cryopreservation and biobanking to amphibian conservation. These are (1) managing the biosecurity (disease risk) of the frogs of New Guinea which are currently free of chytridiomycosis, but are at high risk (2) the Sehuencas water frog of Bolivia, which until recently had only one known surviving male.
自 20 世纪 80 年代以来，由于疾病、栖息地丧失以及入侵物种的影响，两栖动物经历了灾难性的衰退，并且还面临着气候变化带来的持续威胁。目前，大约有 40%的现存两栖动物面临灭绝的威胁，约有 200 个物种已经完全消失。冷冻保存材料的生殖技术和生物库为保护计划提供了技术，可以通过降低成本、更好的遗传管理和减少物种灭绝的风险，提高涉及圈养繁殖和野生种群管理的保护计划的效率和效果。然而，在实地保护计划中，这些技术的应用实例相对较少，我们也不知道在利用冷冻保存遗传物质进行圈养繁殖或野生种群中，遗传多样性是否已经恢复到受到威胁的两栖物种。如果要辅助生殖技术 (ARTs) 和生物库在两栖动物保护中发挥其潜力，就需要解决技术在保护计划中的应用这一差距。我们回顾了一些成功的技术，包括非侵入性配子采集、体外受精和精子冷冻保存，这些技术已经足够成熟，可以应用于许多当前的保护计划。我们还考虑了鱼类和一些海洋无脊椎动物的水胚胎冷冻保存新技术（玻璃化和激光加热），这可能有助于我们克服限制两栖动物卵母细胞和胚胎冷冻保存的因素。最后，我们讨论了两个案例研究，这些案例说明了立即实施 ARTs、冷冻保存和生物库对两栖动物保护的迫切需要和机会。这两个案例是：(1) 管理新几内亚青蛙的生物安全（疾病风险），这些青蛙目前没有壶菌病，但面临着高风险；(2) 玻利维亚的 Sehuencas 水蛙，该物种直到最近才只有一只已知的雄性存活。
