Evaluation of different doses of UV irradiation to loach eggs for genetic inactivation of the maternal genome
Evaluation of different doses of UV irradiation to loach eggs for genetic inactivation of the maternal genome
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DOI：
10.1002/jez.398
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发表时间：
2007-08-01
影响因子：
2.8
通讯作者：
Arai, Katsutoshi
中科院分区：
文献类型：
--
作者：
Fujimoto, Takafumi;Sakao, Suzu;Arai, Katsutoshi
卵核的基因失活是硬骨鱼雄激素胚胎产生中不可或缺的步骤。然而，很少有实验研究集中于确定实现母体基因组完全失活的最有效方法。在这里，我们试图确定使泥鳅卵核完全失活的紫外线（UV）照射的最佳条件。未受精卵从上方接受紫外线照射，剂量范围为 0-200 mJ/cm(2)。通过父系遗传颜色表型的排他性表达来评估母体基因组的成功失活。通过 DNA 含量的流式细胞术和细胞遗传学分析来筛选是否存在假定的母体染色体片段。大多数来自受辐射卵的幼虫具有异常的外观。通过DNA含量流式细胞仪测量和接受超过75 mJ/cm(2)组的染色体计数来检测单倍体个体。尽管125-200 mJ/cm(2)组DNA含量的变异系数明显降低，但在所有受辐照鸡蛋组中仍检测到染色体片段。卵核的失活也通过无核胚胎中是否存在残留核物质从组织学上阐明，该无核胚胎是由紫外线照射的卵子与紫外线照射的精子受精发育而成的。在 150 和 200 mJ/cm(2) 组中发现了完全或接近完全无核的胚胎。我们得出结论，卵核完全基因失活的最佳紫外线剂量超过 150 mJ/cm(2)。
Genetic inactivation of the egg nucleus is an indispensable step in the production of androgenetic embryos in teleosts. However, few experimental studies have focused on determining the most effective means of achieving complete inactivation of the maternal genome. Here, we sought to identify the optimum conditions of ultraviolet (UV) irradiation for complete inactivation of the loach egg nucleus. Unfertilized eggs were UV irradiated from above with a dose in the range 0-200 mJ/cm(2). Successful inactivation of the maternal genome was evaluated by the exclusive expression of a paternally inherited color phenotype. The presence or absence of putative maternal chromosome fragments was screened by flow cytometry of DNA content and by cytogenetic analysis. The majority of the larvae derived from irradiated eggs had an abnormal appearance. Haploid individuals were detected by measurement of DNA content flow cytometry and by chromosome counting in the groups that received more than 75 mJ/cm(2) groups. Although the coefficient of variation of DNA content was apparently reduced in the 125-200 mJ/cm(2) groups, chromosome fragments were still detected in all the groups from irradiated eggs. Inactivation of the egg nucleus was also histologically elucidated by the presence or absence of residual nuclear material in anuclear embryos that developed from UV-irradiated eggs fertilized with UV-irradiated sperm. Embryos that were completely or near-completely anuclear were found in the 150 and 200 mJ/cm(2) groups. We conclude that the optimum UV dose for complete genetic inactivation of the egg nucleus is more than 150 mJ/cm(2).