Gene expression effects of heterosis and ploidy level

描述(申请人提供)：杂种优势通常在表现出较强亲本活力的杂交个体中观察到。已经描述了杂种优势和多倍体效应之间的交互作用，并表明多倍体个体的杂种优势更强。然而，目前还不清楚二倍体杂种优势的分子基础和导致所观察到的与倍性水平相互作用的机制。有几种遗传模型表明，杂种优势要么是有害隐性基因的显性互补，要么是等位基因的交互作用和超显性。然而，这些模型几乎一个世纪都没有变化，现有的数据无法清楚地区分它们。现在可以使用工具来研究杂种优势和多倍体对全基因组表达水平的影响，测试遗传模型，并为潜在的分子机制制定模型。主要集中在玉米基因芯片和基因表达分析上，拟议的实验将使我们能够收集必要的数据来建立杂种优势的分子模型。由于杂种优势对产量的影响，这一结果将对农业具有重要意义，而且作为多倍体和杂种优势的林业进化生物学在许多物种的进化史上都是重要的因素。

DESCRIPTION (provided by applicant): Heterosis is commonly observed in hybrid individuals exhibiting vigor greater either parent. Interactions between the effects of heterosis and polyploidy have been described and indicate that heterosis is stronger in polyploid individuals. However, neither the molecular basis of heterosis in diploids nor the mechanisms leading to the observed interaction with ploidy level are understood at the moment. Several genetic models exist which suggest that heterosis is due to either dominance complementation of deleterious recessives or allelic interactions and overdominance. However, these models have remained unchanged for almost a century, and the available data cannot distinguish them clearly. Tools are now available to investigate heterosis and polyploidy effects on genome-wide expression levels, to test the genetic models, and to formulate a model for the underlying molecular mechanisms. Focusing mainly on the use of microarrays and gene expression analysis in Zea mays, the proposed experiments will allow us collect the necessary data to develop a molecular model for heterosis. The results will be of great significance for agriculture because of the impact of heterosis on yield, and also forevolutionary biology as polyploidy and heterosis are important factors in the evolutionary history of many species.