How petals change their spots: cis-regulatory re-wiring in Clarkia (Onauraceae)
How petals change their spots: cis-regulatory re-wiring in Clarkia (Onauraceae)
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DOI：
10.1111/nph.14163
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发表时间：
2017-10-01
期刊：
影响因子：
9.4
通讯作者：
Rausher, Mark D.
中科院分区：
文献类型：
--
作者：
Martins, Talline R.;Jiang, Peng;Rausher, Mark D.
进化发育生物学中一个长期存在的问题是新特征是如何进化的。虽然大多数花色素沉着的研究都集中在如何色素强度和成分多样化，很少，如果有的话，探讨了如何图案元素可以改变位置。在本研究中，我们研究的遗传变化的基础上的位置的变化，花瓣斑点在Clarkia.Comparative转录组分析被用来确定潜在的候选基因负责斑点的形成。共分离分析F-2个体分离的不同点的位置，定量PCR和焦磷酸测序，被用来确认的候选基因在确定点的位置的作用。利用瞬时表达分析鉴定了不同等位基因的表达域，发现R2 R3 Myb转录因子（CgMyb 1）激活了斑点的形成，CgMyb 1的不同等位基因在不同的区域表达，导致不同花瓣位置的斑点形成。报告基因分析表明，来自不同等位基因的启动子决定了不同的表达位置，位点位置的进化转变是由于CgMyb 1启动子中的一个或多个顺式调节变化，表明模式元件位置的转变可以由单个基因的变化引起，顺式调节重新布线可以用来改变现有字符的相对位置。
A long-standing question in evolutionary developmental biology is how new traits evolve. Although most floral pigmentation studies have focused on how pigment intensity and composition diversify, few, if any, have explored how a pattern element can shift position. In the present study, we examine the genetic changes underlying shifts in the position of petal spots in Clarkia.Comparative transcriptome analyses were used to identify potential candidate genes responsible for spot formation. Co-segregation analyses in F-2 individuals segregating for different spot positions, quantitative PCR, and pyrosequencing, were used to confirm the role of the candidate gene in determining spot position. Transient expression assays were used to identify the expression domain of different alleles.An R2R3Myb transcription factor (CgMyb1) activated spot formation, and different alleles of CgMyb1 were expressed in different domains, leading to spot formation in different petal locations. Reporter assays revealed that promoters from different alleles determine different locations of expression.The evolutionary shift in spot position is due to one or more cis-regulatory changes in the promoter of CgMyb1, indicating that shifts in pattern element position can be caused by changes in a single gene, and that cis-regulatory rewiring can be used to alter the relative position of an existing character.