Trajectory and genomic determinants of fungal-pathogen speciation and host adaptation

作者：Xiao Hu, Guohua Xiao, Peng Zheng, Yanfang Shang, Yao Su, Xinyu Zhang, Xingzhong Liu, Shuai Zhan, Raymond J. St. Leger, Chengshu Wang · 发表于：Proceedings of the National Academy of Sciences · 年份：2014 · DOI：10.1073/pnas.1412662111 · 被引用次数：332 · 研究领域：Nematode management and characterization studies、Entomopathogenic Microorganisms in Pest Control、Mycorrhizal Fungi and Plant Interactions

Much remains unknown regarding speciation. Host-pathogen interactions are a major driving force for diversification, but the genomic basis for speciation and host shifting remains unclear. The fungal genus Metarhizium contains species ranging from specialists with very narrow host ranges to generalists that attack a wide range of insects. By genomic analyses of seven species, we demonstrated that generalists evolved from specialists via transitional species with intermediate host ranges and that this shift paralleled insect evolution. We found that specialization was associated with retention of sexuality and rapid evolution of existing protein sequences whereas generalization was associated with protein-family expansion, loss of genome-defense mechanisms, genome restructuring, horizontal gene transfer, and positive selection that accelerated after reinforcement of reproductive isolation. These results advance understanding of speciation and genomic signatures that underlie pathogen adaptation to hosts.