Department of Animal Sciences, Aquaculture and Water Ecology, Göttingen, Germany.
Sex Dev. 2011;5(5):259-65. doi: 10.1159/000330120. Epub 2011 Jul 28.
In zebrafish, Danio rerio, a polygenic pattern of sex determination or a female heterogamety with possible influences of environmental factors is assumed. The present study focuses on the effects of an elevated water temperature (35° C) during the embryonic development on sex determination in zebrafish. Eggs derived from 3 golden females were fertilized by the same mitotic gynogenetic male and exposed to a water temperature of 35° C, applied from 5 to 10 h post fertilization (hpf), from 5 to 24 hpf, and from 5 to 48 hpf, which correspond to the following developmental stages: gastrula, gastrula to segmentation, and gastrula to pharyngula stage, respectively. Hatching and survival rates decreased with increasing exposure to high water temperatures. Reductions in the hatching and survival rates were not responsible for differences in sex ratios. Accordingly, exposition of the fertilized eggs to a high temperature (35° C) leads to an increase of the male proportion from 22.0% in the controls to a balanced sex ratio (48.3, 47.5, and 52.6%) in the gastrula, segmentation, and pharyngula groups, respectively. These results prove the possibility to change the pathway of sexual determination during early embryonic stages in zebrafish by exposure to a high water temperature.
在斑马鱼中，假设存在一种多基因性别决定模式或雌性异配性，可能受到环境因素的影响。本研究重点关注胚胎发育过程中升高的水温（35°C）对斑马鱼性别决定的影响。从 3 只金色雌性鱼获得的卵子由同一只有丝分裂的雌核雄性鱼受精，并在受精后 5 至 10 小时（hpf）、5 至 24 hpf 和 5 至 48 hpf 时暴露于 35°C 的水温下，分别对应以下发育阶段：原肠胚、原肠胚到体节和原肠胚到咽胚期。孵化率和存活率随着水温升高而降低。孵化率和存活率的降低并不是性别比例差异的原因。因此，将受精卵暴露于高温（35°C）会导致雄鱼比例从对照组的 22.0%增加到原肠胚、体节和咽胚组的平衡性别比例（分别为 48.3%、47.5%和 52.6%）。这些结果证明了在早期胚胎阶段通过暴露于高温来改变斑马鱼性别决定途径的可能性。
