B CHROMOSOME INDUCED MUTAGENESIS IN MAIZE

玉米 B 染色体诱导突变

• 批准号: 3438590
• 负责人: RICK W STAUB
• 金额: $ 7.8万
• 依托单位: CARLETON COLLEGE
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-05-01 至 1990-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3438590
• 关键词: alleles; chromosome aberrations; corn; gene expression; genetic strain; genetic transcription; molecular cloning; molecular genetics; nucleic acid sequence; plant genetics; transposon /insertion element

This proposal is designed to investigate the mutagenic properties of B chromosomes in maize. In particular, it is proposed to investigate whether B chromosomes are indeed mutagenic, whether transposable DNA sequences are involved with this putative mutagenicity, and, more specifically, whether Robertson's Mutator system is involved in a somatic leaf-striping phenotype elicited by the presence of 5 or more B chromosomes. The proposed study is tripartite. In the first part, mutagenicity of B chromosomes will be measured by standard genetic crossing techniques utilizing marker stocks. In the second part, genetically mapped mutant alleles that have arisen in a stock with B chromosomes will be compared to progenitor alleles at the molecular level to determine whether they were caused by insertions-of transposable DNA sequences. In the third part of the study, DNA from white and green sectors of striped leaves will be analyzed at the molecular level for redistribution of Mu sequences. In the last two parts of the study information will be obtained via Southern blotting techniques. There is strong circumstantial evidence that B chromosomes may be mutagenic and that transposable elements may be involved with this mutagenicity. If this proves to be the case, the implications for the study of transposable element systems as well as effects of B chromosomes are far-reaching. Alternatively, should B chromosomes prove to be non-mutagenic and should no evidence for transposability of Mu sequences be found, then valuable information on the activity of Mu sequences (which are known to be present on B chromosomes) may be obtained.

本提案旨在研究致突变性 玉米B染色体。 特别是，建议 研究B染色体是否确实具有致突变性， 转座DNA序列参与了这一假定的 致突变性，更具体地说，罗伯逊突变体 系统参与诱导的体细胞叶条纹表型 5条或更多B染色体。 拟议的研究是由三方面组成的。 第一部分，致突变性 将通过标准遗传杂交测量B染色体的 利用标记股票的技术。 在第二部分中， 基因映射的突变等位基因出现在一个股票， 将B染色体与祖先等位基因进行比较， 以确定它们是否是由 转座DNA序列的插入。 第三部分 研究，DNA从白色和绿色部门的条纹叶将被 在分子水平上分析Mu序列的再分布。 在研究的最后两部分，将通过以下方式获得信息： Southern印迹技术。 有强有力的间接证据表明，B染色体可能是 突变和转座因子可能与此有关 致突变性 如果事实证明是这样， 转座因子系统的研究以及B的作用 染色体的影响深远。 或者，B染色体 证明无致突变性，且无证据表明 Mu序列的可转座性被发现， Mu序列（已知存在于 B染色体）。