Lopes T S, Romagosa E
Department of Animal Science, Universidade Federal do Espirito Santo, Alegre, ES 29500-000, Brazil.
Fishery Institute, APTA, SAA, Sao Paulo, SP 05001-970 Brazil.
Cryo Letters. 2020 Nov-Dec;41(6):323-329.
The gray catfish known as Surubim-do-Paraíba (Steindachneridion parahybae), which is endemic to the Paraíba do Sul river basin, is on the red list of Brazilian fauna threatened with extinction and the cryopreservation of germ cells of this fish is needed in support of conservation.
We aimed to assess the effect of storage temperature on S. parahybae mature and immature oocytes.
Two trials were carried out. Trial I (TI.1-3) used 30 mature oocytes (diameter >1.8 mm) placed in cryoprotectant solutions and submitted to three different techniques. Trial II (TII.1-3) used 30 immature oocytes (diameter <1.6 mm) placed in cryoprotectant solutions and submitted to three storage temperatures (i.e., TII.1 at room temperature for 120 min; TII.2 in the freezer for 120 min; TII.3 in liquid nitrogen for 24 hours.
The mature oocytes were sensitive to every protocol used, including at room temperature. In contrast, the immature oocytes had increased sensitivity according to the temperature reduction to which they were submitted, with the treatment in liquid nitrogen causing greater damage.
The immature stages exhibit more promising results, encouraging further studies using the combination of different CPSs, mainly penetrating ones, in oocyte cryopreservation protocols.
被称为苏鲁比姆-多-帕拉伊巴（Steindachneridion parahybae）的灰鲶鱼是南帕拉伊巴河流域的特有物种，已被列入巴西濒危动物红色名录，因此需要对这种鱼类的生殖细胞进行冷冻保存以支持保护工作。
我们旨在评估储存温度对苏鲁比姆-多-帕拉伊巴成熟和未成熟卵母细胞的影响。
进行了两项试验。试验I（TI.1 - 3）使用30个成熟卵母细胞（直径>1.8毫米），将其置于冷冻保护剂溶液中，并采用三种不同技术处理。试验II（TII.1 - 3）使用30个未成熟卵母细胞（直径<1.6毫米），将其置于冷冻保护剂溶液中，并在三种储存温度下处理（即，TII.1在室温下处理120分钟；TII.2在冰箱中处理120分钟；TII.3在液氮中处理24小时）。
成熟卵母细胞对所使用的每种方案都很敏感，包括在室温下。相比之下，未成熟卵母细胞根据其所处的降温程度敏感性增加，在液氮中的处理造成的损伤更大。
未成熟阶段显示出更有前景的结果，这鼓励在卵母细胞冷冻保存方案中进一步研究使用不同冷冻保护剂（主要是渗透性冷冻保护剂）的组合。
