中科院最新Nature子刊文章

　松材线虫引起的松树萎蔫病是一种危害松树的世界性检疫病害，它的传播需要依赖媒介昆虫——松墨天牛。媒介与线虫发育速度的高度一致是实现传播的基础，但人们对其化学通讯调控机制了解甚少。Ascarosides是2005年在秀丽杆线虫首次发现的一类线虫信息素，调节线虫生长、发育和繁殖。

中国科学院动物研究所孙江华研究组发现ascarosides信息化合物不仅可以由松材线虫产生，其媒介昆虫-松墨天牛也可以产生。冬季，媒介天牛在低温产生大量长链ascs（Asc-C9）诱导自身停滞发育，进入滞育。来年春季，松材线虫扩散型三龄线虫产生短链ascarosides（Asc-C5，Asc-△C6）通过激发蜕皮激素的产生促进媒介天牛变态发育。一旦媒介羽化成成虫，表皮硬化前产生的长链ascarosides （Asc-C9）引诱松材线虫进入气管，被携带转移寄主。此结果表明，ascarosdies在媒介昆虫变态发育和松材线虫病扩散过程中起关键作用（如下图）。

该研究结果于8月1日在线发表于《自然-通讯》（Nature Comunications）（DOI:10.1038/ncomms12341））。动物所博士赵莉蔺为第一作者，研究员孙江华和邹振为通讯作者。该研究得到了中科院B类先导专项及“863”青年科学家专项、国家自然科学基金等的资助。

原文摘要：

Ascarosides coordinate the dispersal of a plant-parasitic nematode with the metamorphosis of its vector beetle

Insect vectors are required for the transmission of many species of parasitic nematodes, but the mechanisms by which the vectors and nematodes coordinate their life cycles are poorly understood. Here, we report that ascarosides, an evolutionarily conserved family of nematode pheromones, are produced not only by a plant-parasitic nematode, but also by its vector beetle. The pinewood nematode and its vector beetle cause pine wilt disease, which threatens forest ecosystems world-wide. Ascarosides secreted by the dispersal third-stage nematode LIII larvae promote beetle pupation by inducing ecdysone production in the beetle and up-regulating ecdysone-dependent gene expression. Once the beetle develops into the adult stage, it secretes ascarosides that attract the dispersal fourth-stage nematode LIV larvae, potentially facilitating their movement into the beetle trachea for transport to the next pine tree. These results demonstrate that ascarosides play a key role in the survival and spread of pine wilt disease.