Bacterial bioluminescence regulates expression of a host cryptochrome gene in the squid-Vibrio symbiosis.
Bacterial bioluminescence regulates expression of a host cryptochrome gene in the squid-Vibrio symbiosis.
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DOI：
10.1128/mbio.00167-13
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发表时间：
2013-04-02
期刊：
影响因子：
6.4
通讯作者：
McFall-Ngai MJ
中科院分区：
文献类型：
--
作者：
Heath-Heckman EA;Peyer SM;Whistler CA;Apicella MA;Goldman WE;McFall-Ngai MJ
鱿鱼Euprymna naplopes和它的发光共生体，弧菌fischeri之间的共生关系，其特点是在双方的合作伙伴和共生体发光的每日波动的日常转录节奏。在这项研究中，我们试图确定共生体是否影响宿主的转录节律。我们在宿主组织中鉴定了两种转录本（E.编码隐花色素（cryptochromes）的cry 1 [escry 1]和escry 2），这些蛋白质影响其他系统的昼夜节律。这两种基因每天都在鱿鱼的头部循环，其模式与其他动物相似，其中某些cry基因的表达受到环境光的影响。相比之下，escry 1表达在共生体定殖的光器官中循环，8倍上调与细菌发光的节律一致，这与白天/夜晚的光机制相抵消。共生体定殖的少年光器官所需的诱导escry 1循环。此外，分析与突变株缺陷的光生产表明，共生发光是必不可少的escry 1的循环，这种缺陷可以补充外源蓝光的介绍。然而，单独的蓝光照射并不能诱导非共生动物的循环，但是将共生体细胞包膜的分子添加到暴露于光的动物中确实恢复了显着的循环活性，这表明光与其他共生体特征协同作用以诱导循环。虽然共生体发光可能是一个字符特定的节奏的鱿鱼弧菌协会，居民微生物的合作伙伴可以同样地影响有据可查的日常节奏在其他系统，如哺乳动物的肠道。在哺乳动物中，肠上皮的生物节律和相关的粘膜免疫系统调节脂质运输和对病原体的免疫应答等多种过程。虽然这些相同的过程受到不同的常驻微生物群的影响，但这些微生物群落控制或受这些节律控制的程度尚未得到解决。这项研究提供的证据表明，三种细菌产品（脂质A，肽聚糖单体，和蓝光）的介绍是需要在共生器官中的隐花色素基因的循环表达。发现细菌可以直接影响基因的转录编码的蛋白质参与夹带的昼夜节律提供了第一个证据的细菌共生体的作用，影响，也许驱动，周边昼夜节律振荡器在主机。
The symbiosis between the squid Euprymna scolopes and its luminous symbiont, Vibrio fischeri, is characterized by daily transcriptional rhythms in both partners and daily fluctuations in symbiont luminescence. In this study, we sought to determine whether symbionts affect host transcriptional rhythms. We identified two transcripts in host tissues (E. scolopes cry1 [escry1] and escry2) that encode cryptochromes, proteins that influence circadian rhythms in other systems. Both genes cycled daily in the head of the squid, with a pattern similar to that of other animals, in which expression of certain cry genes is entrained by environmental light. In contrast, escry1 expression cycled in the symbiont-colonized light organ with 8-fold upregulation coincident with the rhythms of bacterial luminescence, which are offset from the day/night light regime. Colonization of the juvenile light organ by symbionts was required for induction of escry1 cycling. Further, analysis with a mutant strain defective in light production showed that symbiont luminescence is essential for cycling of escry1; this defect could be complemented by presentation of exogenous blue light. However, blue-light exposure alone did not induce cycling in nonsymbiotic animals, but addition of molecules of the symbiont cell envelope to light-exposed animals did recover significant cycling activity, showing that light acts in synergy with other symbiont features to induce cycling. While symbiont luminescence may be a character specific to rhythms of the squid-vibrio association, resident microbial partners could similarly influence well-documented daily rhythms in other systems, such as the mammalian gut. In mammals, biological rhythms of the intestinal epithelium and the associated mucosal immune system regulate such diverse processes as lipid trafficking and the immune response to pathogens. While these same processes are affected by the diverse resident microbiota, the extent to which these microbial communities control or are controlled by these rhythms has not been addressed. This study provides evidence that the presentation of three bacterial products (lipid A, peptidoglycan monomer, and blue light) is required for cyclic expression of a cryptochrome gene in the symbiotic organ. The finding that bacteria can directly influence the transcription of a gene encoding a protein implicated in the entrainment of circadian rhythms provides the first evidence for the role of bacterial symbionts in influencing, and perhaps driving, peripheral circadian oscillators in the host.