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

在前期的研究中，我们观察到小麦与玉米杂交胚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。本研究首次尝试用免疫染色的方法揭示玉米胚中着丝粒的结合蛋白。首次建立了根尖细胞有丝分裂中磷酸化组蛋白H3的观察方法。荧光显微镜下观察信号。然而，在本研究期间，这种方法对第一个合子细胞不起作用。接下来，我们将燕麦和玉米杂交。利用FISH技术可以识别杂交种的染色体。燕麦中的玉米染色体携带正常的着丝粒蛋白。在小麦与珍珠粟的杂交中，谷子的染色体逐渐消失。谷子染色体在胚中的残留率受小麦遗传背景的影响较大。在谷子和小麦染色体中均观察到结构异常。我们试图诱导小麦和玉米或谷子染色体之间的易位。然而，小麦植株携带一部分玉米或碾磨没有出现。

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.