共生表皮葡萄球菌促进果蝇胚后发育

Commensal Staphylococcus epidermidis promoted postembryonic development of Drosophila melanogaster

【背景】动物体定殖有多种共生微生物,这些共生微生物严重影响着宿主生理和病理,日益成为研究热点之一。【目的】分离与鉴定黑腹果蝇共生菌,探究表皮葡萄球菌对黑腹果蝇的发育影响和潜在作用机制。【方法】用CEM培养基(Carotenoid expression medium)从果蝇肠道内分离细菌,通过16SrRNA基因序列比对鉴定菌株;以发育时间和幼虫表面积检测果蝇的发育时期和生长速率;利用实时定量PCR检测果蝇促前胸腺激素与胰岛素通路的激活。【结果】从果蝇体内分离到的菌株为表皮葡萄球菌,该菌可以有效定殖于果蝇的肠道。表皮葡萄球菌通过提高果蝇生长速率而显著促进其发育。在分子水平上,表皮葡萄球菌激活PTTH和胰岛素信号以刺激宿主的生长发育。【结论】表皮葡萄球菌是果蝇的一种共生菌,可以通过调控PTTH和胰岛素信号而刺激果蝇生长发育。

[Background] Animals harbor many microbial species that exert profound effects on host physiology and pathology, currently emerging as one of investigational hotspots.[Objective] To explore Staphylococcus epidermidis effects on the developmental timing of Drosophila melanogaster.[Methods]The bacteria were isolated from the fly guts by carotenoid expression medium(CEM), and the bacterial species were further determined by using 16 S rRNA gene sequence. The growth and development of flies were detected. Real-time quantitative PCR was used to detect the activation of the prothoracicotropic hormone(PTTH) and insulin pathway in flies.[Results] The isolated strain was identified as S. epidermis,which was able to effectively colonize in the guts of flies. S. epidermis accelerated the development of D.melanogaster by promoting the growth rate. At the molecular level, S. epidermis activated PTTH and insulin signals to stimulate the growth of hosts.[Conclusion] S. epidermis was a commensal bacterium of flies, which stimulated the growth and development of flies by regulating PTTH and insulin signals.