蚜虫次级内共生菌的多样性和功能

内共生菌与其寄主之间的关系一直都是生物学研究的热点。蚜虫类昆虫的内共生菌分为初级内共生菌(Buchnera)和一些次级内共生菌。Buchnera与蚜虫寄主之间有密切的营养共生关系,对蚜虫寄主的生长发育至关重要。虽然次级内共生菌在蚜虫体内含量相对较少,但是随着研究的不断深入,次级内共生菌无论对蚜虫寄主的生态行为(抵御寄生蜂、耐高温特性、体色形成等)还是物种形成和进化的影响都不容忽视。此外,次级内共生菌基因组序列的测定,也促进了功能基因学的发展。在系统梳理已发表文献的基础上,本文主要综述了蚜虫次级内共生菌的基本特征、多样性、及其对蚜虫寄主的生态影响,进而对未来值得关注的问题进行了展望。

Diversity and functions of the secondary endosymbionts in aphids

Symbiotic associations between symbionts and their hosts have being a hot research topic in biology. Aphids contain the primary endosymbiont Buchnera and several major secondary endosymbionts within their bodies. Buchnera and aphid hosts have a strict nutritional mutualism, which is critical to the normal development of aphids. Although the secondary endosymbionts have lower population densities than Buchnera in aphids, more and more studies show that they have important impact on the ecology and behavior (e.g. parasite wasp resistance, higher temperature tolerance, body color) as well as speciation and evolution of their aphid hosts. In addition, functional genomics have been facilitated with the sequencing of secondary endosymbiont genomes. This paper reviews basic characteristics, diversity and the ecological functions of secondary endosymbionts of aphids, and highlights several scientific questions worthy of concern in the future.