植菌昆虫与其共生真菌协同进化分子机制

昆虫菌业（fungiculture）是一种类似于人类种植业的昆虫种植体系,包括种植、耕作、收获和营养依赖4个过程,可分为高级的社会性昆虫如切叶蚂蚁、白蚁等和低级的非社会性昆虫如食菌小蠹虫、卷叶象甲、蜥蜴甲虫、树蜂等,它们均能种植并取食真菌。近年来随着组学及微生物组技术的发展,植菌昆虫与其共生真菌协同进化的分子机制研究方面取得了重要进展。系统发育分析阐明了植菌昆虫的起源与进化历程,并显示出与共生真菌系统发育的一致性;共生真菌细胞核数量也从双核增加到最多17个核,而染色体倍型也从单倍体增加为二倍体甚至多倍体;组学分析则揭示了植菌昆虫与其共生真菌在精氨酸、碳水化合物、木质素及几丁质合成或降解等方面显示出了高度的协同进化。本文系统综述了植菌昆虫及其共生真菌的系统进化、核进化及基因组进化进展,并探讨这种协同进化机制的生物学意义。

Convergent evolutionary mechanism between fungus-growing insects and symbiotic fungi: a review

Insect fungiculture is an insect-growing system similar to human farming, including four processes of habitual planting, cultivation, harvest and nutritional dependency. Fungiculture can be maintained by advanced social insects such as leaf-cutter ants, termites, etc. and low-level non-social insects such as ambrosia beetles, leaf-rolling weevils, lizard beetles, and wood wasps that can grow and feed on fungal cultures. Many recent breakthroughs in the molecular mechanism of co-evolution of fungus-growing insects and their symbiotic fungi have been facilitated by omics and microbiome technology. Phylogenetic analysis clarifies that the origin and evolution of fungus-growing insects are highly consistent with insect symbiotic fungi. The number of symbiotic fungal nuclei also increases from dinuclear type to up to 17 nuclei while chromosomal haplotypes also increase from haploid to diploid or even polyploid. Genomics analysis also reveals a high degree of synergistic evolution in terms of arginine, carbohydrates, lignin and chitin metabolisms. This paper summarizes the phylogenetic evolution, nuclear evolution and genomic evolution of fungus-growing insects and their symbiotic fungi, and proposes the biological significance of this co-evolutionary molecular mechanism.