Elizabethkingia anophelis: Physiologic and Transcriptomic Responses to Iron Stress
Elizabethkingia anophelis: Physiologic and Transcriptomic Responses to Iron Stress
复制标题
DOI：
10.3389/fmicb.2020.00804
复制
发表时间：
2020-05-07
影响因子：
5.2
通讯作者：
Walker, Edward D.
中科院分区：
文献类型：
--
作者：
Chen, Shicheng;Johnson, Benjamin K.;Walker, Edward D.
在这项研究中，我们调查了全球的基因表达的Anopheles stephensi雌性斯氏按蚊喂养蔗糖或血液中肠的铁通量的按蚊，在铁贫或富铁的文化条件。在RNAseq技术揭示的3,686个转录本中，218个在缺铁条件下上调，112个下调。溶血素基因的表达显着抑制时，细胞在富铁或高温（37摄氏度）条件下生长。此外，溶血素基因表达下调后，血液餐，表明E。按蚊细胞通过限制铁负荷来响应过量的铁及其相关的生理应激。相反，编码呼吸链蛋白的基因在富铁条件下上调，使这些含铁蛋白螯合细胞内游离铁。体内研究表明，E.按蚊细胞在吸血蚊子中比在蔗糖喂养的蚊子中增加3倍。铁载体合成基因的缺失导致细胞在富铁和贫铁培养基中的生长受损。突变体表现出更敏感的H2 O2毒性和更少的生物膜形成比野生型细胞。蚊子E.实验中，在肠道中定植的按蚊比那些用红霉素处理或未处理的按蚊产生更多的卵。结果表明，E.按蚊细菌对蚊子肠道中不同的铁浓度作出反应，在抵御铁相关应激的同时收获铁，有助于红细胞的溶解，并积极影响蚊子宿主的繁殖力。
In this study, we investigated the global gene expression responses of Elizabethkingia anophelis to iron fluxes in the midgut of female Anopheles stephensi mosquitoes fed sucrose or blood, and in iron-poor or iron-rich culture conditions. Of 3,686 transcripts revealed by RNAseq technology, 218 were upregulated while 112 were down-regulated under iron-poor conditions. Hemolysin gene expression was significantly repressed when cells were grown under iron-rich or high temperature (37 degrees C) conditions. Furthermore, hemolysin gene expression was down-regulated after a blood meal, indicating that E. anophelis cells responded to excess iron and its associated physiological stress by limiting iron loading. By contrast, genes encoding respiratory chain proteins were up-regulated under iron-rich conditions, allowing these iron-containing proteins to chelate intracellular free iron. In vivo studies showed that growth of E. anophelis cells increased 3-fold in blood-fed mosquitoes over those in sucrose-fed ones. Deletion of siderophore synthesis genes led to impaired cell growth in both iron-rich and iron-poor media. Mutants showed more susceptibility to H2O2 toxicity and less biofilm formation than did wild-type cells. Mosquitoes with E. anophelis experimentally colonized in their guts produced more eggs than did those treated with erythromycin or left unmanipulated, as controls. Results reveal that E. anophelis bacteria respond to varying iron concentration in the mosquito gut, harvest iron while fending off iron-associated stress, contribute to lysis of red blood cells, and positively influence mosquito host fecundity.