Pathways for making unisexual flowers and unisexual plants:Moving beyond the "two mutations linked on one chromosome" model.
Pathways for making unisexual flowers and unisexual plants:Moving beyond the "two mutations linked on one chromosome" model.
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DOI：
10.3732/ajb.1600029
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发表时间：
2016-04
影响因子：
3
通讯作者：
S. Renner
中科院分区：
文献类型：
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作者：
S. Renner
高等植物性别决定具有重要的生物学意义，对果实产量和优质种子生产具有重要的现实意义。在过去的几十年里，人们对典型的两性花的遗传发育的理解出现了爆炸性的变化；然而，控制二性花(单性花)和雌雄异株(单性个体)的基因直到现在才被揭示(Akagi等人，2014；Boualem等人，2015)。这些来自远亲群体的遗传发育洞见，现在需要与大量的经验观察结合在一起，这些观察表明，二倍体和雌雄异体各自独立进化了数千次，但往往在相同的属和家族中，提出了相关的进化路径(达尔文，1877；劳埃德，1972,1975a，b，1980；Renner和Rickleff，1995；Renner，2014)。在这里，我强调最近的洞察力可能会改变我们对开花植物雌雄异株途径的理解。被子植物雌雄异株进化的基本模式长期以来一直是这样的：“至少两个基因突变是将两性或雌雄同株物种转变为具有不同性别的物种所必需的；一个突变必须影响胚珠的产生，而另一个突变必须影响花粉的产生”(Charlesworth and Charlesworth，1978：p.975)，由此推论“在大多数物种中，决定性别的不同基因被聚集在一条染色体的一个区域”(p.976)。这一模型忽略了(1)在雌雄同株物种中，不需要出现抑制雄性和雌性功能的突变，因为它们已经存在，并且(2)几乎没有证据表明雌雄异株植物中的性别决定基因聚在一起在一条染色体上。发育-遗传学
Sex determination in higher plants is of fundamental biological interest and has great practical significance for fruit yield and high-quality seed production. Th e last decades have witnessed an explosion in the genetic-developmental understanding of a typical hermaphroditic flower; however, the genes controlling dicliny (unisexual fl owers) and dioecy (unisexual individuals) are only now being revealed ( Akagi et al., 2014 ; Boualem et al., 2015 ). These genetic-developmental insights, from distantly related groups, now need to be brought together with the large body of empirical observations showing that dicliny and dioecy each evolved independently many thousands of times, but oft en in the same genera and families suggesting related evolutionary pathways ( Darwin, 1877 ; Lloyd, 1972 , 1975a , b , 1980 ; Renner and Ricklefs, 1995 ; Renner, 2014 ). Here I highlight how the recent insights may redirect our understanding of pathways to dioecy in fl owering plants. Th e fundamental model for the evolution of dioecy in angiosperms has long been that “at least two gene mutations are necessary to transform an hermaphroditic or monoecious species into one with separate sexes; one mutation must aff ect ovule production, and the other the production of pollen” ( Charlesworth and Charlesworth, 1978 : p. 975), with the corollary that “diff erent genes determining sex [are] grouped together in one region of one chromosome in most species” (p. 976). Th is model disregards that (1) in monoecious species, mutations suppressing male and female function do not need to arise since they already exist and that (2) there is little evidence that sex-determining genes in dioecious plants are grouped together on one chromosome. Th e developmental-genetic