Gene expression effects of heterosis and ploidy level

描述（由申请人提供）：杂种优势常见于杂交个体，表现出比亲本更强的活力。杂种优势和多倍体效应之间的相互作用已经被描述，并表明杂种优势在多倍体个体中更强。然而，二倍体杂种优势的分子基础和导致观察到的与倍性水平相互作用的机制目前还不清楚。现有的几种遗传模型表明，杂种优势是由于有害隐性显性的显性互补或等位基因相互作用和显性。然而，这些模型在近一个世纪以来一直保持不变，现有的数据无法清楚地区分它们。现在已经有工具可以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的应用上，所提出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，该研究结果对农业和进化生物学都具有重要意义，因为多倍体和杂种优势是许多物种进化史上的重要因素。

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.