The heterochronic maize mutant Corngrass1 results from overexpression of a tandem microRNA
The heterochronic maize mutant Corngrass1 results from overexpression of a tandem microRNA
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DOI：
10.1038/ng2001
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发表时间：
2007-04-01
期刊：
影响因子：
30.8
通讯作者：
Hake, Sarah
中科院分区：
文献类型：
--
作者：
Chuck, George;Cigan, A. Mark;Hake, Sarah
在成年繁殖阶段保留幼年特征是一种被称为幼态繁殖的过程的特征，人们对它是否有助于新物种的进化存在猜测。玉米的显性玉米草1 （Cg1）突变体是一种新染色体突变，其导致的表型可能存在于玉米的草状祖先中。我们克隆了Cg1，发现它编码两个串联miR156基因，这两个基因在分生组织和侧壁器官中过表达。此外，Cg1的靶标是teosinte glume architecture1 (tga1) 1，该基因在teosinte驯化玉米中发挥了作用。过表达miR156的Cg1突变植株mir172水平较低，mir172是一种靶向控制幼体发育基因的microRNA(2)。通过改变这两种microrna的相对水平，有可能延长或缩短玉米幼体发育，从而为物种水平的异时性变化如何在自然界中发生提供了一种机制。
Retention of juvenile traits in the adult reproductive phase characterizes a process known as neoteny, and speculation exists over whether it has contributed to the evolution of new species. The dominant Corngrass1 (Cg1) mutant of maize is a neotenic mutation that results in phenotypes that may be present in the grass-like ancestors of maize. We cloned Cg1 and found that it encodes two tandem miR156 genes that are overexpressed in the meristem and lateral organs. Furthermore, a target of Cg1 is teosinte glume architecture1 (tga1) 1, a gene known to have had a role in the domestication of maize from teosinte. Cg1 mutant plants overexpressing miR156 have lower levels of mir172, a microRNA that targets genes controlling juvenile development(2). By altering the relative levels of both microRNAs, it is possible to either prolong or shorten juvenile development in maize, thus providing a mechanism for how species-level heterochronic changes can occur in nature.