Gene Duplication and Transference of Function in the paleoAP3 Lineage of Floral Organ Identity Genes.
Gene Duplication and Transference of Function in the paleoAP3 Lineage of Floral Organ Identity Genes.
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DOI：
10.3389/fpls.2018.00334
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发表时间：
2018
影响因子：
5.6
通讯作者：
Di Stilio VS
中科院分区：
文献类型：
--
作者：
Galimba KD;Martínez-Gómez J;Di Stilio VS
APETALA 3（AP 3）是一个MADS盒转录因子，参与雄蕊和花瓣的发育，属于花发育ABC模型的B类。毛茛科（Ranunculaceae），一个新兴的模式，在非核心真双子叶植物，有AP 3同源物来自古代和现代的基因复制。先前的工作表明，在毛茛科中，花瓣反复地和独立地丢失，与特定的AP 3 partial的丢失相关，而Thalumtrum代表了这些实例之一。本研究的主要目的是进行功能分析的三个AP 3的直系同源物中存在的Thatritrum thalictroides，代表paleoAP 3基因谱系，以确定基因复制后的冗余与分歧的程度。由于Thaltrum缺乏花瓣，并已失去花瓣特异性AP 3，我们还问是否异位表达的其余AP 3基因有助于部分转移花瓣功能的第一轮昆虫授粉的物种中发现。为了解决这些问题，我们进行了功能特性的病毒诱导的基因沉默（VIGS），蛋白质-蛋白质相互作用和结合位点分析。我们的结果表明唐松草AP 3之间存在部分冗余，在雄蕊身份中深度保留了B类功能，并在萼片异位花瓣状体中发挥了新的作用。失去的AP 3基因座的花瓣功能的某些方面显然已经转移到其他旁系同源物。一个新的结果是，蛋白质产物不仅相互作用，而且作为同源二聚体。这里提供的证据还表明，不同ThtAP 3旁系同源物的表达是紧密整合的，在编码截短蛋白的旁系同源物之一沉默后，B功能稳态明显被破坏。为了解释这一结果，我们提出了两个可测试的替代方案：截短的蛋白质是一个显性负突变体或有一个补偿响应作为备份电路的一部分。通过酵母双杂交结合在所有B类基因启动子中检测到AP 3特异性结合基序的混杂蛋白质-蛋白质相互作用的证据为这些假设提供了部分支持。
The floral organ identity gene APETALA3 (AP3) is a MADS-box transcription factor involved in stamen and petal identity that belongs to the B-class of the ABC model of flower development. Thalictrum (Ranunculaceae), an emerging model in the non-core eudicots, has AP3 homologs derived from both ancient and recent gene duplications. Prior work has shown that petals have been lost repeatedly and independently in Ranunculaceae in correlation with the loss of a specific AP3 paralog, and Thalictrum represents one of these instances. The main goal of this study was to conduct a functional analysis of the three AP3 orthologs present in Thalictrum thalictroides, representing the paleoAP3 gene lineage, to determine the degree of redundancy versus divergence after gene duplication. Because Thalictrum lacks petals, and has lost the petal-specific AP3, we also asked whether heterotopic expression of the remaining AP3 genes contributes to the partial transference of petal function to the first whorl found in insect-pollinated species. To address these questions, we undertook functional characterization by virus-induced gene silencing (VIGS), protein–protein interaction and binding site analyses. Our results illustrate partial redundancy among Thalictrum AP3s, with deep conservation of B-class function in stamen identity and a novel role in ectopic petaloidy of sepals. Certain aspects of petal function of the lost AP3 locus have apparently been transferred to the other paralogs. A novel result is that the protein products interact not only with each other, but also as homodimers. Evidence presented here also suggests that expression of the different ThtAP3 paralogs is tightly integrated, with an apparent disruption of B function homeostasis upon silencing of one of the paralogs that codes for a truncated protein. To explain this result, we propose two testable alternative scenarios: that the truncated protein is a dominant negative mutant or that there is a compensational response as part of a back-up circuit. The evidence for promiscuous protein–protein interactions via yeast two-hybrid combined with the detection of AP3 specific binding motifs in all B-class gene promoters provide partial support for these hypotheses.
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影响因子：
14.8
作者：
Kelley LA;Mezulis S;Yates CM;Wass MN;Sternberg MJ
通讯作者：
Sternberg MJ
影响因子：
11.4
作者：
Davies, B;EgeaCortines, M;Sommer, H
通讯作者：
Sommer, H
DOI：
10.1073/pnas.92.12.5273
发表时间：
1995-06-06
影响因子：
11.1
作者：
HEARD, J;DUNN, K
通讯作者：
DUNN, K
DOI：
10.1073/pnas.0604883103
发表时间：
2006-08-01
影响因子：
11.1
作者：
Kafri, Ran;Levy, Melissa;Pilpel, Yitzhak
通讯作者：
Pilpel, Yitzhak
影响因子：
4.1
作者：
Jaramillo, M. Alejandra;Kramer, Elena M.
通讯作者：
Kramer, Elena M.