DNA Synthesis in Rice Endosperm

水稻胚乳核的DNA含量，而不是停留在 预期的3C水平增加到更高的值。 的问题 被问到的问题如下。 这是什么样的模式 胚乳核中DNA的合成和积累 整个组织的发育过程 如果胚乳 细胞核的DNA含量呈现出模式增加，这是 易发生细胞融合、多倍性、多线性、核内复制 还是选择性基因扩增 有证据表明 在个体发育过程中某些基因的表达不足， 胚乳？ 放射自显影（包括DNA纤维 放射自显影）和Feulgen显微镜方法将 用于研究DNA合成的变化模式， 积累 胚乳DNA的再结合动力学研究 叶或胚DNA和克隆基因将被用于 确定高DNA含量是否是由于 核内复制或基因扩增。 的动力学 胚乳DNA和rRNA之间杂交将被分析， 确定rRNA基因是否在 胚乳发育

The DNA content of rice endosperm nuclei, instead of remaining at the expected 3C level, increases to higher values. The questions that are being asked are the following. What is the pattern of DNA synthesis and accumulation in endosperm nuclei during the entire course of development of this tissue? If the endosperm nuclei exhibits a modal increase in DNA content, is this referable to cell fusion, polyploidy, polyteny, endoreduplication or selective gene amplification? Is there evidence for the under.representation of certain genes during the ontogeny of the endosperm? Autoradiographic (including DNA fiber autoradiography) and Feulgen microspectrophotometic methods will be used to study the changing pattern of DNA synthesis and accumulation. The reassociation kinetics of endosperm DNA with leaf or embryo DNA and with cloned genes will be employed to establish whether the high DNA content is due to endoreduplication or gene amplification. The kinetics of hybridization between endosperm DNA and rRNA will be analyzed to determine whether the rRNA genes are under.replicated during endosperm development.