Ocalewicz Konrad, Gurgul Artur, Dobosz Stefan, Jasielczuk Igor, Szmatoła Tomasz, Semik-Gurgul Ewelina, Kucharski Mirosław, Rożyński Rafał
Department of Marine Biology and Biotechnology, Faculty of Oceanography and Geography, University of Gdańsk, 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.
Genes (Basel). 2025 Jul 8;16(7):803. doi: 10.3390/genes16070803.
BACKGROUND/OBJECTIVES: Fish eggs activated with UV-irradiated spermatozoa and exposed to the High Hydrostatic Pressure (HHP) shock to inhibit first cell cleavage develop as gynogenetic Doubled Haploids (DHs) that are fully homozygous individuals. Due to the expression of the recessive genes and side effects of the gamete treatment, survival of fish DHs is rather low, and most of the mitotic gynogenotes die before hatching. Nevertheless, as maternal gene products provided during oogenesis control the initial steps of embryonic development in fish, a maternal effect on the survival of gynogenotes needs to be also considered to affect efficiency of gynogenesis. Thus, the objective of this research was to apply an RNA-seq approach to discriminate transcriptional differences between rainbow trout () eggs with varied abilities to develop after gynogenetic activation.
Gynogenetic development of rainbow trout was induced in eggs originated from eight females. Maternal RNA was isolated and sequenced using RNA-Seq approach. Survival rates of gynogenotes and transcriptome profiles of eggs from different females were compared.
RNA-seq analysis revealed substantial transcriptional differences between eggs originated from different females, and a significant correlation between the ability of the eggs for gynogenesis and their transcriptomic profiles was observed. Genes whose expression was altered in eggs with the increased survival of DHs were mostly associated (GO BP) with the following biological processes: development, cell differentiation, cell migration and protein transport. Some of the genes are involved in the oocyte maturation (), apoptosis (, ) and early embryogenesis, including maternal to zygotic transition ().
Inter-individual variation of the transcription of maternal genes correlated with the competence of eggs for gynogenesis suggest that at least part of the mortality of the rainbow trout DHs appear before activation of zygotic genome and expression of the lethal recessive traits.
背景/目的：用紫外线照射过的精子激活鱼卵，并使其经受高静水压（HHP）冲击以抑制第一次细胞分裂，这样发育而成的雌核发育二倍体单倍体（DHs）是完全纯合的个体。由于隐性基因的表达以及配子处理的副作用，鱼类DHs的存活率相当低，并且大多数有丝分裂雌核发育体在孵化前死亡。然而，由于卵子发生过程中提供的母体基因产物控制着鱼类胚胎发育的初始步骤，因此也需要考虑母体效应对雌核发育体存活的影响，以影响雌核发育的效率。因此，本研究的目的是应用RNA测序方法来区分经雌核发育激活后具有不同发育能力的虹鳟鱼（）卵之间的转录差异。
在源自8只雌性的鱼卵中诱导虹鳟鱼的雌核发育。使用RNA测序方法分离并测序母体RNA。比较了不同雌性的雌核发育体的存活率和卵的转录组图谱。
RNA测序分析揭示了源自不同雌性的卵之间存在显著的转录差异，并且观察到卵的雌核发育能力与其转录组图谱之间存在显著相关性。在DHs存活率增加的卵中表达发生改变的基因大多（GO BP）与以下生物学过程相关：发育、细胞分化、细胞迁移和蛋白质运输。其中一些基因参与卵母细胞成熟（）、细胞凋亡（，）和早期胚胎发生，包括母型向合子型转变（）。
母体基因转录的个体间差异与卵的雌核发育能力相关，这表明虹鳟鱼DHs的至少部分死亡率出现在合子基因组激活和致死隐性性状表达之前。
