Department of Ichthyology and Aquaculture, University of Warmia and Mazury in Olsztyn, Warszawska St. 117 A, 10-719 Olsztyn, Poland.
Department of Marine Biology and Ecology, Institute of Oceanography, Faculty of Oceanography and Geography, University of Gdansk, 81-378 Gdynia, M. Piłsudskiego 46 Av, Poland.
Anim Reprod Sci. 2022 Feb;237:106929. doi: 10.1016/j.anireprosci.2022.106929. Epub 2022 Jan 26.
Use of parental individuals from allochthonous lineages to produce stocking specimens resulted in genetic contamination of many local European grayling (Thymallus thymallus) populations. Stocking programs including triploid individuals that are not able to reproduce with stocks located in natural habitats due to being reproductively sterile could contribute to populations of the European grayling and prevent regional lineages from the genetic pollution. The main goal of the present research, therefore, was to provide conditions for triploidization of the European grayling and examine gonads of triploid individuals. High Hydrostatic Pressure (HHP) shock (9000 psi/5 min.) applied to activated and incubated grayling eggs at 10 °C between the 17 min. 30 sec. and 20 minute timepoints subsequent to the time of insemination resulted in inhibition of the second polar body release and triploidization. Histological analysis confirmed that all 1-yr-old cytogenetically confirmed triploids had gonadal tissues indicative of sterility with the gonads being composed of connective tissue including fibroblasts, adipocytes and degenerated epithelial structures without there being any differentiated germ cells detected. There were no differences in the body length and Fulton's condition factor between 1 year old diploid and triploid grayling, however, the average body weight was markedly less in triploid than diploid specimens. Although, 1-yr-old triploid European female and male graylings did not have fully developed gonads, before these triploid specimens are deemed safe, as a result of being reproductively sterile for stocking in natural grayling habitats, there needs to be further examination of the 2- and 3-year-old triploid specimens.
利用来自异地谱系的亲代个体来生产放流标本，导致许多欧洲灰鳟（Thymallus thymallus）种群的遗传污染。由于生殖不育，放流计划包括不能与自然栖息地中种群繁殖的三倍体个体，可能会对欧洲灰鳟种群产生影响，并防止区域谱系受到遗传污染。因此，本研究的主要目标是为欧洲灰鳟的三倍体化提供条件，并检查三倍体个体的性腺。在 10°C 下，对激活和孵化的灰鳟卵施加高静压（HHP）冲击（9000 psi/5 分钟），在授精后 17 分 30 秒至 20 分钟的时间点之间，抑制第二极体的释放并导致三倍体化。组织学分析证实，所有 1 龄细胞遗传学上确认的三倍体都具有性腺组织，表明不育，性腺由包括成纤维细胞、脂肪细胞和退化的上皮结构在内的结缔组织组成，没有检测到任何分化的生殖细胞。1 龄二倍体和三倍体灰鳟的体长和富尔顿的状况因素没有差异，然而，三倍体标本的平均体重明显低于二倍体标本。尽管 1 龄的三倍体欧洲雌、雄灰鳟的性腺没有完全发育，但在这些三倍体标本被认为安全之前，由于生殖不育，不适合在自然灰鳟栖息地中放流，还需要进一步检查 2 龄和 3 龄的三倍体标本。
