PDF(Pubmed)
Abstract：
Heritable symbionts are common among animals in nature, but the molecular mechanisms underpinning symbiont invasions of host populations have been elusive. In this study, we demonstrate the spread of Rickettsia in an invasive agricultural pest, the whitefly Bemisia tabaci Mediterranean (MED), across northeastern China from 2018 to 2023. Here, we show that the beneficial symbiont Rickettsia spreads by manipulating host hormone signals. Our analyses suggest that Rickettsia have been horizontally acquired by B. tabaci MED from another invasive whitefly B. tabaci Middle East-Asia Minor 1 during periods of coexistence. Rickettsia is transmitted maternally and horizontally from female B. tabaci MED individuals. Rickettsia infection enhances fecundity and results in female bias among whiteflies. Our findings reveal that Rickettsia infection stimulates juvenile hormone (JH) synthesis, in turn enhancing fecundity, copulation events, and the female ratio of the offspring. Consequently, Rickettsia infection results in increased whitefly fecundity and female bias by modulating the JH pathway. More female progeny facilitates the transmission of Rickettsia. This study illustrates that the spread of Rickettsia among invasive whiteflies in northeastern China is propelled by host hormone regulation. Such symbiont invasions lead to rapid physiological and molecular evolution in the host, influencing the biology and ecology of an invasive species.
摘要：
可遗传的共生体在自然界的动物中很常见，但是支撑宿主种群共生体入侵的分子机制一直难以捉摸。在这项研究中,我们证明了立克次体在入侵农业害虫中的传播，地中海白粉虱烟粉虱（MED），2018年至2023年横跨中国东北。这里,我们表明，有益的共生体立克次体通过操纵宿主激素信号传播。我们的分析表明，在共存期间，B.tabaciMED已从另一种侵入性粉虱B.tabaci中东-亚洲小牛1水平获得立克次体。立克次体从女性烟粉虱MED个体母体和水平传播。立克次体感染可增强繁殖力，并导致粉虱中的女性偏见。我们的发现表明立克次体感染刺激幼体激素（JH）合成，反过来增强繁殖力，交配事件,和后代的雌性比例。因此,立克次体感染通过调节JH途径导致粉虱繁殖力增加和女性偏见。更多的雌性后代促进立克次体的传播。这项研究表明，立克次体在中国东北地区侵袭性粉虱中的传播是由宿主激素调节推动的。这种共生生物的入侵导致宿主的快速生理和分子进化，影响入侵物种的生物学和生态学。
