Comparative studies of the establishment of sexual identity in flowers of non-model species

我用比较的方法来研究分生组织的结构和发育潜力，分生组织是植物中活跃分裂细胞的区域。比较发育研究被用来阐明模式和发展可检验的假说，关于如何改变遗传途径，导致形态上不同的形式。我的研究计划的中心目标是获得一个更好地了解早期发育事件在分生组织的水平，导致成熟的植物器官的形式使用的物种表现出不寻常的形态。我的短期目标集中在花的同源异形的研究上。同源异型是指特定类型的器官在它们通常不发育的部位生长。本文将从天南星科的拟花植物和锦葵科的木槿属植物两个系统来研究这一现象。1. Aroids的圆柱形花序：一些Aroids物种的圆柱形花序由上部的雄花和下部的雌花组成，以及这两个区域之间的两性花。这些两性花代表了一种独特的同源异型现象，即雌性器官（又名心皮）被同一轮上的雄性器官（又名雄蕊）所取代。2.芙蓉的“双花”：在芙蓉中，双花产生许多雄蕊以及花瓣状花器官，在典型花中通常专门用于雄蕊产生的甜甜圈状分生组织环上。 在这两个系统中，我想确定是否有一般的关系，表征一种类型的器官被另一种替代，以揭示潜在的发育限制和潜在的机制。此外，我计划确定花器官的身份基因同源物和他们的模式，在启动和发展的早期阶段的表达。我还计划使用测序技术来比较雄、雌和非典型花的转录组（基因表达谱）。3.真实的时间形态建成技术的发展：虽然在文献中报道了花器官的发育系列，它们主要是基于几个连续的“静态”发育阶段的组合。很少有研究试图使用单个分生组织在真实的时间内记录发育，因为固有的局限性阻止了形态发生的连续跟踪而不引起损害。 在我们实验室的初步工作相结合的分生组织和扫描电子显微镜的微培养显示出很大的希望，作为一个有用的方法来捕捉和表征分生组织和它形成的器官之间的关系的动态性质。本研究的主要目的是定量分析花原基的大小和花序分生组织的大小之间的关系在Aroids;同样，我们也将分析花器官的大小和形状与花分生组织的大小和形状在芙蓉。

I use a comparative approach to study the structure and developmental potential of meristems, which are regions of actively dividing cells in plants. Comparative developmental studies are used to elucidate patterns and develop testable hypotheses on how genetic pathways can be altered to lead to morphologically different forms. The central goal of my research program is to gain a better understanding of early developmental events at the level of meristems that lead to the form of mature plants organs using species that exhibit uncommon morphologies. My short-term objectives focus on studies dealing with homeosis in flowers. Homeosis refers to the growth of specific types of organs in sectors where they normally don't develop. I will study this phenomenon in two systems: Aroids (Araceae) and Hibiscus (Malvaceae). 1. Cylindrical inflorescences of Aroids: A number of Aroid species with cylindrical inflorescences consist of male flowers in the upper portion and females in the lower portion, as well as a sector of bisexual flowers between these two zones. These bisexual flowers represent a unique case of homeosis where female organs (aka carpels) are replaced by male organs (aka stamens) on the same whorl. 2. 'Double' flowers of Hibiscus: In Hibiscus rosa-sinensis, double flowers produce a number of stamens as well as petaloid floral organs on a donut-shaped meristematic ring normally designated exclusively for stamen production in typical flowers. In both systems, I want to determine if there are general relationships that characterize the substitution of one type of organ by another to uncover potential developmental constraints and underlying mechanisms. Additionally, I plan to identify floral organ identity gene homologues and their patterns fo expression during early stages of initiation and development. I also plan to use sequencing techniques to compare transcriptomes (gene expression profiles) of male, female, and atypical flowers in Aroids. 3. Real time morphogenesis technique development: Although developmental series of floral organs are reported in the literature, they are mainly based on an assemblage of several sequential 'static' developmental stages. There are very few studies that have attempted to document development in real time using a single meristem because of inherent limitations that prevent continuous track of morphogenesis without eliciting damage.  Preliminary work in our laboratory combining the micro culture of meristematic tissues and scanning electron microscopy shows great promise as a useful approach to capture and characterize the dynamic nature of the relationship between a meristem and the organs it forms. The main objective of this study will be to quantitatively analyze the relationships between the size of floral primordia and the size of inflorescence meristem in Aroids; similarly we will also analyze the size and shape of floral organs in relation to the size and shape of the floral meristem in Hibiscus.