Evolutionary Diversification of Photosynthesis and the Anoxygenic to Oxygenic Transition

J.Touchman博士(亚利桑那州立大学)、R.BlankHilp博士(华盛顿州州立大学)和M.Madigan博士(南伊利诺伊大学)正在对五种光合原核生物进行基因组测序和代谢分析。选择这个项目的生物是为了提供比现在可用的更广泛的光营养类群基因组覆盖范围。该项目的主要目标是利用基因组数据来了解光合作用的起源和进化，并探索从缺氧到产氧的转变机制。被测序的生物包括生活在低温(嗜冷)、高温(嗜热)、高pH(嗜碱)、定期干燥的环境和硫化物含量高的环境中的物种。所选择的生物包括两种螺旋细菌，卷曲螺旋藻和束状嗜热菌；四种蛋白质细菌，北极红丝藻，全球红酵母，绿色芽孢杆菌和热色杆菌；以及一种蓝藻，Leptolyngbya(又名。Oscillatoria)两栖类。变形细菌包括贝塔和伽马部分的成员，以及一种含有细菌叶绿素b作为其主要光色素的细菌。完成的带注释的基因组序列正被用来填补光合原核生物现有基因组数据中的巨大空白。这些生物体的代谢能力也在使用途径分析软件工具进行分析。每一种生物都有其独特的特征，可以将其纳入基因组测序项目，包括进化关系、农业应用和环境方面。图奇曼参与了亚利桑那州立大学的BE生物学家项目。所有的调查人员都让本科生和高中生在他们的实验室里进行序列分析和注释活动。

Drs. J. Touchman (Arizona State Univ), R. Blankenship (Washinton State Univ) and M. Madigan (Southern Illinois Univ.) are carrying out the genome sequencing and metabolic analysis of five photosynthetic prokaryotes. Organisms for this project were chosen to provide significantly wider coverage of genomes of phototrophic taxa than is now available. The broad goals of the project are to use the genomic data to understand the origin and evolution of photosynthesis and to explore mechanisms of the anoxygenic to oxygenic transition. The organisms being sequenced include species that live at low temperature (psychrophilic), high temperature (thermophilic), high pH (alkaliphilic), in environments subject to periodic drying, and environments high in sulfide. The organisms chosen include two heliobacteria, Heliorestis convoluta and Heliophilum fasciatum; four proteobacteria, Rhodoferax antarcticus, Rhodopila globiformis, Blastochloris viridis, and Thermochromatium tepidum; and one cyanobacterium, Leptolyngbya (a.k.a. Oscillatoria) amphigranulata. The proteobacteria include members from the beta and gamma divisions and one that contains bacteriochlorophyll b as its principal photopigment. The finished, annotated genome sequences are being used to fill large gaps in the available genomic data for photosynthetic prokaryotes. The metabolic capabilities of these organisms are also being analyzed using pathway analysis software tools. Each organism has individual characteristics that justify its inclusion in a genome-sequencing project, including evolutionary relationships, agricultural applications and environmental aspects.Dr. Touchman is involved in the Be a Biologist program at ASU. All of the investigators are involving undergraduate and high school students in sequence analysis and annotation activities in their labs.