PROKARYOTIC SWARM CELL DIFFERENTIATION & PHOTOPERCEPTION

描述（改编自申请人摘要）：本提案是 以研究群体细胞分化为中心， 由细菌Rhodoacillum centenum产生的光感知。 本种 区别于具有单个极鞭毛用于 在液体中运动成多鞭毛群细胞，其能够 在固体表面上的快速运动性。 申请人的研究表明， 这个R。Centenum具有独特的固体表面感知机制， 随后诱导群细胞分化。 为了研究这个过程， 将表征分化突变体。 运动性突变体 致病菌霍乱弧菌、沙门氏菌、空肠弯曲杆菌和 已知幽门螺杆菌的毒性明显低于野生型 类型细胞。 奇异变形杆菌的群体细胞分化突变体具有 也被证明在感染膀胱的能力上有缺陷， 肾 这些结果表明，运动性和转化为群体细胞 是某些病原体的重要毒力决定因子。 信息 因此，从这项研究中获得的信息可能具有重要的实际意义。 关于病原微生物的侵袭性的影响。 R. Centenum群细胞集落也表现出显着的能力， 快速地向光或远离光迁移。 由于许多突变体在 对群体细胞分化研究在光感 感知，这使我们能够从基因上剖析光的过程， perception. 光合微生物能够形成大量的 水华在水环境中，光，温度，含氧量和 营养是最佳的，有几个物种产生有毒的代谢物， 会对人类和动物造成致命威胁。 光驱动分析 因此，集落运动性对于光敏生物学的研究具有广泛的意义。 各种能动的细菌所表现出的能动性。

DESCRIPTION (Adapted from the applicants abstract): This proposal is centered on an investigation of swarm cell differentiation and photoperception by the bacterium Rhodospirillum centenum. This species differentiates from a cell type that has a single polar flagellum used for motility in liquids into a multiflagellated swarm cell which is capable of rapid motility on solid surfaces. The applicant's studies have demonstrated that R. Centenum has a unique mechanism of solid surface perception and subsequent induction of swarm cell differentiation. To study this process, differentiation mutants will be characterized. Motility mutants of the pathogenic bacteria Vibrio cholerae, Salmonella, Campylogbacter jejuni and Helicobacter pylori are know to be significantly less virulent than wild type cells. Swarm cell differentiation mutants of Proteus mirabilis have also been shown to be defective in their ability to infect the bladder or kidney. These results indicate that motility and conversion to swarm cells is an important virulence determinant for some pathogens. Information obtained from this study could therefore have significant practical implications regarding the invasiveness of pathogenic microorganisms. R. Centenum swarm cell colonies also exhibit the remarkable ability to rapidly migrate toward or away from light. Since many mutants obtained in the study of swarm cell differentiation are defective in photosensory perception, this allows us to genetically dissect the process of light perception. Photosynthetic microorganisms are capable of forming massive blooms in aqueous environments where light, temperature, oxygenicity and nutrients are optimal, with several species producing toxic metabolites that can cause deadly threats to humans and animals. Analysis of light-driven colony motility thus has broad implications for the study of photosensory motility exhibited by a variety of motile bacteria.