Laboratory of Cell Engineering, Department of Pharmaceutical Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
Laboratory of Cell Engineering, Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
Sci Rep. 2017 Feb 17;7:42852. doi: 10.1038/srep42852.
Many endemic fish species are threatened with extinction. Conservation strategies and the restoration of endemic fish after extinction must therefore be investigated. Although sperm cryopreservation is indispensable for the conservation of endangered fishes, the limited number of mature fish and limited availability (volume and period) of sperm from small endemic fish hinders the optimization and practical use of this material. In this report, we demonstrate the in vitro differentiation of fertile sperm from cryopreserved spermatogonia of juveniles of the endangered small cyprinid honmoroko (Gnathopogon caerulescens), which is endemic to Lake Biwa in Japan. The entire process of spermatogenesis was recapitulated in vitro using cryopreserved spermatogonia of non-spawning adult and juvenile fish. The differentiation of sperm from spermatogonia was captured as a time-lapse video and confirmed by 5-ethynyl-2'-deoxyuridine (EdU) incorporation into sperm. Fertility was demonstrated by artificial insemination. These results suggest that the combination of cryopreservation of spermatogonia and in vitro sperm differentiation will provide a new and promising strategy for the preservation of paternal genetic materials.
许多地方特有的鱼类物种都面临灭绝的威胁。因此，必须研究保护策略和灭绝后地方特有鱼类的恢复。尽管精子冷冻保存对于濒危鱼类的保护是必不可少的，但成熟鱼类数量有限，以及小型地方特有鱼类精子的有限可用性（数量和时间），阻碍了这种材料的优化和实际应用。在本报告中，我们展示了来自濒危小型鲤科鱼类 honmoroko（Gnathopogon caerulescens）的冷冻保存精原细胞的体外分化，该鱼类是日本琵琶湖的特有种。使用非产卵成年和幼鱼的冷冻保存精原细胞在体外重现了整个精子发生过程。通过 5-乙炔基-2'-脱氧尿苷（EdU）掺入精子来捕获精原细胞向精子的分化，并通过人工授精证明了其受精能力。这些结果表明，精原细胞的冷冻保存与体外精子分化相结合，将为保存父本遗传物质提供一种新的、有前途的策略。
