Department of Marine Biology and Biotechnology, Faculty of Oceanography and Geography, University of Gdansk, M. Piłsudskiego 46 Av, 81-378, Gdynia, Poland.
Center for Experimental and Innovative Medicine, University of Agriculture in Kraków, Redzina 1C, 30-248, Krakow, Poland.
J Appl Genet. 2024 Dec;65(4):897-905. doi: 10.1007/s13353-024-00887-8. Epub 2024 Jun 26.
Expression of the telomerase reverse-transcriptase (TERT) gene and activity of telomerase have been reported in the somatic tissues and gonads in fish irrespective of their age and size. Nevertheless, little is known about TERT expression in the fish eggs. In the current study, the presence of the TERT transcripts was confirmed in the rainbow trout ovulated eggs before and after activation with nonirradiated and UV-irradiated (gynogenesis) sperm. Eggs originating from eight females had high and comparable quality expressed by similar hatching rates. However, survival of the gynogenetic larvae that hatched from eggs activated with UV-irradiated sperm and further exposed to the high hydrostatic pressure (HHP) shock for duplication of the maternal chromosomes varied between females from 2.1 ± 0.4 to 40.5 ± 2.2%. Increased level of TERT transcripts was observed in eggs originating from two females, and gametes from only one of them showed improved competence for gynogenesis (27.3 ± 1.9%). In turn, eggs from the female that exhibited the highest survival after gynogenetic activation were characterized by the lowest expression of the TERT gene. Telomerase in rainbow trout eggs may compensate erosion of the telomeres during early embryonic development; however, its upregulation does not assure better development after gynogenetic activation.
端粒酶逆转录酶 (TERT) 基因的表达和端粒酶的活性已在鱼类的体细胞组织和性腺中被报道,无论其年龄和大小如何。然而,关于鱼类卵中 TERT 表达的信息却知之甚少。在本研究中,在未辐照和辐照(雌核发育)精子激活前后的虹鳟排卵卵中证实了 TERT 转录本的存在。来自 8 只雌鱼的卵具有高且可比的质量,表现为相似的孵化率。然而,从用辐照精子激活并进一步暴露于高静压(HHP)冲击以复制母染色体的卵中孵化的雌核发育幼虫的存活率在雌性之间差异很大,从 2.1±0.4 到 40.5±2.2%不等。在来自两名雌性的卵中观察到 TERT 转录本水平升高,并且只有其中一名雌性的配子显示出雌核发育的改善能力(27.3±1.9%)。相反,在雌核发育激活后表现出最高存活率的雌性的卵的 TERT 基因表达最低。虹鳟鱼卵中的端粒酶可能补偿了早期胚胎发育过程中端粒的磨损;然而,其上调并不能确保雌核发育激活后的更好发育。