RoL: FELS: EAGER: Genetic Constraints on the Increase of Organismal Complexity Over Time

在植物和动物中，新的专门身体部位的出现都是罕见的。专门化器官似乎起源于现有器官的专门化版本，但它们的专门化要求同一器官的不同副本之间的监管存在差异。这个项目将测试一项拟议的生命规则，该规则指出，当有机体的整个染色体在进化过程中复制时，多细胞生物体进化中最大和最复杂的变化更容易实现。全基因组复制和身体部位数量增加之间的联系被认为可以解释早期四足动物的进化或开花植物的出现，但这些现象很难进行实验研究，因为它们发生在数千万年或数亿年前。最近的一个事件是，在玉米中出现了两种类型的花序(花序排列在茎上)，用于雄性和雌性生殖--雄穗和穗；相比之下，玉米的近亲只产生一种类型的花序。这项研究将利用玉米和高粱的比较遗传学技术，确定当打开或关闭时，哪些遗传系统会改变花序类型。该项目将在机构UCARE和REU项目的支持下，为本科生提供有价值的培训。这个迫切的项目检验了这样一种假设，即玉米专门化生殖器官的发育和进化是由一组非专门性器官发育所需的一组祖先基因的专门化组合控制的，在全基因组多倍化过程中进行复制之前，该专门化基因是控制玉米专门化生殖器官的。多倍化玉米和非多倍化高粱中同线异源基因敲除的产生和表型特征将为直系同源猜想提供系统的测试，这一生命规则告诉我们，通过物种形成进化的基因倾向于保留功能，而通过复制产生的基因倾向于进化相关但不相同的功能。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

In both plants and animals, the emergence of new specialized body parts is rare. Specialized organs appear to originate as specialized versions of existing organs, yet their specialization requires a divergence in regulation between different copies of the same organ. This project will test a proposed rule of life, that states that the largest and most complex changes in the evolution of multicellular organisms are easier to achieve when the entire set of chromosomes of an organism is duplicated in the course of evolution. Links between whole genome duplication and an increase in the number of body parts has been suggested to explain the evolution of early tetrapods or the emergence of flowering plants, but these are harder to study experimentally as they have occurred tens or hundreds of millions of years ago. A more recent event is the emergence in corn with two types of inflorescences (group or cluster of flowers arranged on a stem) for male and female reproduction - tassel and ear; contrasting to the situation in close relatives of maize that produce only a single type of inflorescence. This research will use comparative genetics techniques in maize and one such relative, sorghum, to identify which genetic systems, when turned on or off, change the inflorescence types. The project will provide valuable training to undergraduate students, supported by institutional UCARE and REU programs.This EAGER project tests the hypothesis that the development and evolution of specialized reproductive organs of maize are controlled by the specialized ensembles of duplicate copies of one set of ancestral genes that was required for development of non-specialized sexual organ, before it underwent a duplication in the course of the whole-genome polyploidization. Generation and phenotypic characterization of knockouts of syntenic orthologous genes in polyploidized maize and nonpolyploidized sorghum will provides a systematic test of the Ortholog Conjecture, a rule of life that tells that genes evolved by speciation tend to preserve function, whereas genes produced by duplication tend to evolve related but not identical functions.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.