Studies on chromosome elimination mechanism in hybrid embryos by super-wide crosses (II)

在以前的研究中，我们观察到在小麦和玉米杂交胚胎中，玉米染色体的着丝粒不与纺锤体纤维相互作用，因此玉米染色体在第一次合子分裂中被消除。在本研究中，我们首先尝试通过免疫染色的方法揭示玉米胚着丝粒结合蛋白。我们首次建立了观察根尖细胞有丝分裂中组蛋白H3磷酸化的方法。用带去卷积系统的荧光显微镜观察信号。然而，在本研究期间，这种方法不适用于第一批合子细胞。接下来，我们制作了燕麦和玉米的杂交品种。利用FISH技术可以在杂交种中识别出玉米染色体。燕麦中的玉米染色体携带正常着丝粒蛋白。在小麦与珍珠谷杂交中，谷子的染色体逐渐消失。谷子染色体残留在胚胎中的频率受到小麦遗传背景的显著影响。谷子和小麦的染色体都出现了结构异常。我们试图诱导小麦和玉米或谷子的染色体易位。然而，携带部分玉米或碾磨的小麦植株并未出现。

In previous study, we observed that the centromere of maize chromosomes in hybrid embryos between wheat and maize does not interact with spindle fibers, and that thus the maize chromosomes are eliminated in the first zygotic division. In this study we first tried to reveal the centromere binding proteins in maize centromere in the embryos by immuno-staining method. We first developed the method to observe phosphorylate histone H3 in mitosis of root tip cells. The signals were observed by fluorescent microscope with deconvolution system. This method did not work for the first zygotic cells, however, in the period of this study. Next, we made hybrids between oat and maize. We could recognize maize chromosomes by FISH in the hybrids. The maize chromosomes in oat carried normal centromere proteins. In the cross between wheat and pearl millet, the millet's chromosomes were gradually eliminated. The frequency of millet chromosomes remained in the embryos was significantly affected by the genetic background of wheat. Structural abnormality was observed both in the millet and wheat chromosomes. We tried to induce translocation between the chromosomes of wheat and maize or millet. However, wheat plants carrying a part of maize or milled did not appeared.