Secondary Symbiotic Origin of Algal Plastids and the Phylogeny of the Bangiophycidae (Rhodophyta)

爱荷华州大学的Dejerish Bhattacharya博士获得了一笔赠款，用于确定红藻（红藻门）的进化史或进化树。红藻是重要的初级生产者，也是许多其他光合细胞发生的关键参与者，这一过程被称为次级内共生。在次级内共生中，现存的藻类被其他单细胞原生生物吞噬，并作为光合机器（质体）无限期地维持在细胞中。在红藻和其它含有红藻次级内共生体的藻类的质体基因组中编码的基因（例如，褐藻类和隐藻藻类）进行研究，以确定次生内共生发生的频率，以及哪种红藻是不同藻类群体中质体的供体。红藻的生物多样性是基础生物学研究的有机体的无限储存库，也是重要商业产品的资源。此外，藻类是氧气的重要供应者，也是二氧化碳的消费者，二氧化碳是一种有助于温室效应的气体。虽然藻类生物学的问题已经研究的程度远远低于致力于“模型”系统的努力，现代分子生物学的出现使科学家能够扩大他们的研究范围，以所有的生命形式。红藻项目涉及现代生物学研究的两个基石，确定我们星球上的生物多样性，并利用自然界中的分类群来解决有关单个物种和整个谱系的起源和多样化的基本问题。红藻的共生性将为解决系统学和生物多样性问题提供坚实的基础，而质体基因树将帮助我们了解何时以及如何通过次生内共生创造新的光合谱系。

DEB-0107754Debashish BhattacharyaA grant has been awarded to Dr. Debashish Bhattacharya at the University of Iowa to determine the phylogeny, or evolutionary tree, of the red algae (Rhodophyta). The red algae are important primary producers and key players in the genesis of a multitude of other photosynthetic cells though a process termed secondary endosymbiosis. In secondary endosymbiosis, existing algae are engulfed by other single-celled protists and maintained indefinitely as photosynthetic machines (plastids) in the cell. Genes encoded in the plastid genomes of red algae and other algae containing red algal secondary endosymbionts (e.g., brown and cryptophyte algae) will be studied to determine how often secondary endosymbiosis has occurred, and which red alga was the donor of the plastid in the different algal groups. The red algal phylogeny will also be the basis for a much-needed taxonomic revision of the Rhodophyta.The biodiversity of the algae is an infinite reservoir of organisms for fundamental biological research, and a resource for commercially important products. Furthermore, the algae are important suppliers of oxygen as well as consumers of carbon dioxide, a gas that contributes to the green-house effect. Although problems in algal biology have been studied to a much lesser extent than efforts devoted to "model" systems, the advent of modern molecular biology has enabled scientists to broaden their scope of investigation to all life forms. The red algal project touches on two cornerstones of modern biological research, determining the biodiversity on our planet, and using taxa in nature to address fundamental questions about the origin and diversification of individual species and whole lineages. The red algal phylogeny will provide a firm basis for addressing issues in systematics and biodiversity, whereas the plastid gene tree will help us understand when and how often novel photosynthetic lineages have been created through secondary endosymbiosis.