Vibrio fischeri uses two quorum-sensing systems for the regulation of early and late colonization factors
Vibrio fischeri uses two quorum-sensing systems for the regulation of early and late colonization factors
复制标题
DOI：
10.1128/jb.187.11.3620-3629.2005
复制
发表时间：
2005-06-01
影响因子：
3.2
通讯作者：
Ruby, EG
中科院分区：
文献类型：
--
作者：
Lupp, C;Ruby, EG
费氏弧菌具有ain和lux两种群体感应系统，以酰基高丝氨酸内酯为信号分子。我们之前已经证明，ain系统激活发光基因表达所需的细胞密度低于lux系统激活所需的细胞密度，并且这两个系统对于鱿鱼宿主Euprymna scoloes的持续定植是必不可少的。在这里，我们询问两个系统的相对贡献在不同的殖民阶段是否也很重要。群体感应基因的失活延迟了共生关系的启动。此外，我们的数据表明，勒克斯群体感应在殖民化的早期阶段并不完全活跃，这意味着直到共生后期才需要这个系统。fischeri V. luxI突变体在共生关系中不表达可检测的光水平，但却像野生型一样启动定植，这表明群体感应调节定植因素而不是发光。我们使用了最近开发的费氏弧菌微阵列来鉴定由蚁群感应控制的基因，这些基因可能与起始缺陷有关。我们发现了30个差异调节基因，包括一些运动基因的抑制。与这些数据一致，一个群体感应突变体在体外表现出改变的运动行为。综上所述，这些数据表明，随着细胞密度的增加，这两种群体感应系统的顺序激活允许通过非群体感应对早期定植因子（如运动性）进行特定调节，而晚期定植因子（如发光）则优先由lux群体感应进行调节。
Vibrio fischeri possesses two quorum-sensing systems, ain and lux, using acyl homoserine lactones as signaling molecules. We have demonstrated previously that the ain system activates luminescence gene expression at lower cell densities than those required for lux system activation and that both systems are essential for persistent colonization of the squid host, Euprymna scolopes. Here, we asked whether the relative contributions of the two systems are also important at different colonization stages. Inactivation of ain, but not lux, quorum-sensing genes delayed initiation of the symbiotic relationship. In addition, our data suggest that lux quorum sensing is not fully active in the early stages of colonization, implying that this system is not required until later in the symbiosis. The V. fischeri luxI mutant does not express detectable light levels in symbiosis yet initiates colonization as well as the wild type, suggesting that ain quorum sensing regulates colonization factors other than luminescence. We used a recently developed V. fischeri microarray to identify genes that are controlled by ain quorum sensing and could be responsible for the initiation defect. We found 30 differentially regulated genes, including the repression of a number of motility genes. Consistent with these data, ain quorum-sensing mutants displayed an altered motility behavior in vitro. Taken together, these data suggest that the sequential activation of these two quorum-sensing systems with increasing cell density allows the specific regulation of early colonization factors (e.g., motility) by ain quorum sensing, whereas late colonization factors (e.g., luminescence) are preferentially regulated by lux quorum sensing.