Functional reversion to identify controlling genes in multigenic responses: analysis of floral abortion
Functional reversion to identify controlling genes in multigenic responses: analysis of floral abortion
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DOI：
10.1093/jxb/erl177
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发表时间：
2007-01-01
影响因子：
6.9
通讯作者：
McLaughlin, John E.
中科院分区：
文献类型：
--
作者：
Boyer, John S.;McLaughlin, John E.
在许多情况下，生物体对刺激的反应是通过改变大量基因的活性来实现的。其中，某些基因可能控制表型，而其他基因则起次要作用或被动改变，而不直接影响表型。事实证明，识别控制基因很困难。然而，在少数情况下，通过生理或生化手段逆转表型是可能的，而不会改变有机体的遗传学。在这种功能逆转过程中，只有几个基因可能会做出反应，从而识别那些可能控制表型的基因。玉米缺水期间的花败育就是一个例子，因为这种反应本身是多基因的，表型可以通过生理/生化手段逆转。最近的一项分析利用这种逆转揭示了只有几个基因可能控制堕胎表型。在玉米中，这些基因编码细胞壁转化酶(Incw2)、可溶性转化酶(IVr2)、核糖体失活蛋白(RIP2)和磷脂酶D(PLD1)。转化酶似乎控制着卵巢对糖的正常吸收。它们的下调耗尽了卵巢糖库，导致核糖体失活蛋白和磷脂酶基因上调。后一种变化似乎启动了衰老，使细胞膜降解，从而导致不可逆转的流产。有了这些发现，这些基因就成为了防止堕胎的靶点。这种方法在其他情况下可能会有价值，但需要一些其他方法。
In many situations, organisms respond to stimuli by altering the activity of large numbers of genes. Among these, certain ones are likely to control the phenotype while others play a secondary role or are passively altered without directly affecting the phenotype. Identifying the controlling genes has proven difficult. However, in a few instances, it has been possible to reverse the phenotype by physiological or biochemical means without altering the genetics of the organism. During this functional reversion, only a few genes may respond, thus identifying those likely to be controlling the phenotype. Floral abortion during a water shortage in maize is an example because the response is inherently multigenic, and the phenotype can be reversed by physiological/biochemical means. A recent analysis used this reversal to reveal that only a few genes are likely to control the abortion phenotype. In maize, these genes coded for a cell wall invertase (Incw2), a soluble invertase (Ivr2), a ribosome-inactivating protein (RIP2), and phospholipase D (PLD1). The invertases appeared to control the normal sugar uptake by the ovaries. Their down-regulation depleted ovary sugar pools and resulted in an up-regulation of the genes for ribosome-inactivating protein and for phospholipase. The latter changes appeared to initiate senescence that degraded cell membranes, thus causing irreversible abortion. With these findings, these genes have become targets for preventing abortion. This approach might have value in other contexts with some additional methods.