MAPPING AND CHARACTERIZING QUANTITATIVE TRAITS IN MAIZE

数量效应小而非主要的基因 将绘制和描述质量影响。 的 这项工作所依据的假设表明，“野生型” 基因是多态性的，对基因的表达有不同但很小的影响。 携带它们的个体的表型。 当它们发生突变时， 这些基因具有重要的作用并显示孟德尔遗传。 支持这一想法的实验证据进行了讨论。 玉米是 容易操纵基因，是一个非常多态的物种 因此有助于定量的表征 性状基因座 两个大的重组近交系已被使用 构建一个跨越整个基因组的地图。 这些家庭 将首先用于绘制影响数量的遗传因素， 性状：重组，抗病性，植物性状， 对环境的反应。 映射应导致 鉴定当突变时显示孟德尔遗传基因 种族隔离 这些基因将被分子克隆， 通过映射建立的相关性可以通过以下方式证明： 分离的“野生型”等位基因确实具有定量的 他们表达的差异。 在这里学习的人物 对植物科学和农学更感兴趣，这项工作 重要影响的定量因素的研究 医学重要性 重组自交系已经建立 在小鼠中，但与它们相关的地图仍然不完整。 人类家庭的地图绘制同样利用了一些相同的 为重组近交家庭建立的想法。 玉米 因此是一个模型系统，其中数量性状基因座可以更多地 易于绘制和表征。

Genes having small quantitative effects rather than major qualitative effects will be mapped and characterized. The hypothesis upon which this work is based suggests that "wild-type" genes are polymorphic and have varying but small effects on the phenotype of the individual carrying them. When they are mutant, these genes have major effects and show Mendelian inheritance. Experimental evidence supporting this idea is discussed. Maize is easily manipulated genetically and is a very polymorphic species and therefore lends itself to the characterization of quantitative trait loci. Two large recombinant inbred families have been used to construct a map that spans the entire genome. These families will be used first to map genetic factors affecting quantitative traits: recombination, disease resistance, plant characters, and response to the environment. Mapping should lead to the identification of genes which, when mutant, show Mendelian segregation. These genes will be molecularly cloned so that the correlation established by mapping can be proved by showing that the segregating "wild-type" alleles indeed have quantitative differences in their expression. While the characters studied here are of more interest to plant science and agronomy, the work has important implications for the study of quantitative factors of medical importance. Recombinant inbred lines have been established in mice, but maps associated with them are still incomplete. Mapping in human families likewise makes use of some of the same ideas that were established for recombinant inbred families. Maize is thus a model system where quantitative trait loci can more easily be mapped and characterized.