Nonsyntenic Genes Drive Highly Dynamic Complementation of Gene Expression in Maize Hybrids
Nonsyntenic Genes Drive Highly Dynamic Complementation of Gene Expression in Maize Hybrids
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DOI：
10.1105/tpc.114.130948
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发表时间：
2014-10-01
期刊：
影响因子：
11.6
通讯作者：
Hochholdinger, Frank
中科院分区：
文献类型：
--
作者：
Paschold, Anja;Larson, Nick B.;Hochholdinger, Frank
玉米（Zea mays）表现出异常水平的结构基因组多样性，这在高等真核生物中可能是独一无二的。在这项研究中，我们调查了两个玉米自交系的遗传差异如何影响其 F1 杂交后代的四种不同主根组织的转录组景观。经常观察到一种极端的互补情况：基因仅在一个亲本中表达，但在两个互惠杂种中表达。检测到 2341 个基因的这种单亲表达 (SPE) 模式，每个组织多达 1287 个 SPE 模式。因此，杂交体中每个组织中的活性基因数量比其亲本多出 400 个以上。 SPE 模式具有高度动态性，其组织特异性过高 (80%) 就说明了这一点。这种类型互补的生物学意义是基于以下观察结果：与所有表达基因 (36%) 相比，不成比例的大量 SPE 基因 (75% 至 82%) 是非同线的。这些基因可能是在最后一次全基因组复制后进化的，因此比同线性基因更年轻。总之，SPE基因在玉米杂交种的根组织和互补性之间塑造了显着的基因表达可塑性，导致F1杂交种与其近交亲本相比活性基因的组织特异性增加。
Maize (Zea mays) displays an exceptional level of structural genomic diversity, which is likely unique among higher eukaryotes. In this study, we surveyed how the genetic divergence of two maize inbred lines affects the transcriptomic landscape in four different primary root tissues of their F1-hybrid progeny. An extreme instance of complementation was frequently observed: genes that were expressed in only one parent but in both reciprocal hybrids. This single-parent expression (SPE) pattern was detected for 2341 genes with up to 1287 SPE patterns per tissue. As a consequence, the number of active genes in hybrids exceeded that of their parents in each tissue by >400. SPE patterns are highly dynamic, as illustrated by their excessive degree of tissue specificity (80%). The biological significance of this type of complementation is underpinned by the observation that a disproportionally high number of SPE genes (75 to 82%) is nonsyntenic, as opposed to all expressed genes (36%). These genes likely evolved after the last whole-genome duplication and are therefore younger than the syntenic genes. In summary, SPE genes shape the remarkable gene expression plasticity between root tissues and complementation in maize hybrids, resulting in a tissue-specific increase of active genes in F1-hybrids compared with their inbred parents.