An Imprinted Gene Underlies Postzygotic Reproductive Isolation in Arabidopsis thaliana
An Imprinted Gene Underlies Postzygotic Reproductive Isolation in Arabidopsis thaliana
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DOI：
10.1016/j.devcel.2013.08.006
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发表时间：
2013-09-16
影响因子：
11.8
通讯作者：
Kohler, Claudia
中科院分区：
文献类型：
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作者：
Kradolfer, David;Wolff, Philip;Kohler, Claudia
响应倍性间杂交的合子后生殖隔离是植物中众所周知的现象，它形成同域物种形成的主要途径。倍体间杂交失败的一个主要决定因素是胚乳，这是一种支持胚胎生长的营养组织，类似于哺乳动物胎盘的功能作用。尽管有人认为失调的印记基因支撑着胚乳的剂量敏感性，但这种现象的分子基础仍然未知。在三价种子败育抑制因子的遗传筛选中，我们鉴定了父系表达的印记基因 ADMETOS (ADM)。在这里，我们提供的证据表明，增加 ADM 剂量会导致三倍体种子停滞。大量的理论工作预测，失调的印记基因会造成倍体间杂交的障碍。因此，我们的研究提供了有力支持这一假设的证据，并为我们理解植物合子后杂交障碍提供了分子基础。
Postzygotic reproductive isolation in response to interploidy hybridizations is a well-known phenomenon in plants that forms a major path for sympatric speciation. A main determinant for the failure of interploidy hybridizations is the endosperm, a nutritious tissue supporting embryo growth, similar to the functional role of the placenta in mammals. Although it has been suggested that deregulated imprinted genes underpin dosage sensitivity of the endosperm, the molecular basis for this phenomenon remained unknown. In a genetic screen for suppressors of trip-bid seed abortion, we have identified the paternally expressed imprinted gene ADMETOS (ADM). Here, we present evidence that increased dosage of ADM causes triploid seed arrest. A large body of theoretical work predicted that deregulated imprinted genes establish the barrier to interploidy hybridization. Our study thus provides evidence strongly supporting this hypothesis and generates the molecular basis for our understanding of postzygotic hybridization barriers in plants.