3月18日的Nature上，发表了来自Broad研究所，阿姆斯特丹大学，加州大学，西班牙，法国等国际研究团队经过基因组对比分析发现镰菌属真菌宿主选择的遗传差异。
镰菌属真菌是真菌中的重要类群，其分布广泛，可生存在土壤等多种环境中。镰孢菌的许多种类是重要的植物病原菌， 如由尖孢镰孢菌等镰孢菌侵染引起的瓜类枯萎病是瓜类生产上的主要病害之一， 尤以黄瓜、西瓜和甜瓜上的危害最为严重。
有些镰孢菌属真菌宿主选择范围很宽，而有些则选择范围较窄。为了了解不同菌种对宿主选择的分子机制，科学家们对三个宿主选择范围有宽有窄的镰菌属真菌（其中两个刚完成测序）Fusarium graminearum, Fusarium verticillioides 和 Fusarium oxysporum f. sp.lycopersici进行了比较基因组研究，这些基因组比对是为了解是驱动这些差异的线索。
科学家们研究分析表明，在镰菌属真菌基因组的种属特异性序列占据整个基因组的1/4，包含4个同源染色体。这个种属特异性的区域包含大量的转座子和有进化痕迹的基因，这些基因与致病性有很大关系。科学家们尝试将两个菌种在标准生长介质上混合（将来自一个尖孢镰刀菌番茄病原体的两个完整染色体转移），就能将一个非致病菌种变成一个致病菌种。
这些发现为了解宿主范围及致病性的演化提供了线索。（生物谷Bioon.com）
生物谷推荐原文出处：
Nature doi:10.1038/nature08850
Comparative genomics reveals mobile pathogenicity chromosomes in Fusarium
Li-Jun Ma1,26, H. Charlotte van der Does2,26, Katherine A. Borkovich3, Jeffrey J. Coleman4, Marie-Josée Daboussi5, Antonio Di Pietro6, Marie Dufresne5, Michael Freitag7, Manfred Grabherr1, Bernard Henrissat8, Petra M. Houterman2, Seogchan Kang9, Won-Bo Shim10, Charles Woloshuk11, Xiaohui Xie12, Jin-Rong Xu11, John Antoniw13, Scott E. Baker14, Burton H. Bluhm11, Andrew Breakspear15, Daren W. Brown16, Robert A. E. Butchko16, Sinead Chapman1, Richard Coulson17, Pedro M. Coutinho8, Etienne G. J. Danchin8,27, Andrew Diener18, Liane R. Gale15, Donald M. Gardiner19, Stephen Goff20, Kim E. Hammond-Kosack13, Karen Hilburn15, Aurélie Hua-Van5, Wilfried Jonkers2, Kemal Kazan19, Chinnappa D. Kodira1,27, Michael Koehrsen1, Lokesh Kumar1, Yong-Hwan Lee21, Liande Li3, John M. Manners19, Diego Miranda-Saavedra22, Mala Mukherjee10, Gyungsoon Park3, Jongsun Park21, Sook-Young Park9,27, Robert H. Proctor16, Aviv Regev1, M. Carmen Ruiz-Roldan6, Divya Sain3, Sharadha Sakthikumar1, Sean Sykes1, David C. Schwartz23, B. Gillian Turgeon24, Ilan Wapinski1, Olen Yoder25, Sarah Young1, Qiandong Zeng1, Shiguo Zhou23, James Galagan1, Christina A. Cuomo1, H. Corby Kistler15 & Martijn Rep2
Fusarium species are among the most important phytopathogenic and toxigenic fungi. To understand the molecular underpinnings of pathogenicity in the genus Fusarium, we compared the genomes of three phenotypically diverse species: Fusarium graminearum, Fusarium verticillioides and Fusarium oxysporum f. sp. lycopersici. Our analysis revealed lineage-specific (LS) genomic regions in F. oxysporum that include four entire chromosomes and account for more than one-quarter of the genome. LS regions are rich in transposons and genes with distinct evolutionary profiles but related to pathogenicity, indicative of horizontal acquisition. Experimentally, we demonstrate the transfer of two LS chromosomes between strains of F. oxysporum, converting a non-pathogenic strain into a pathogen. Transfer of LS chromosomes between otherwise genetically isolated strains explains the polyphyletic origin of host specificity and the emergence of new pathogenic lineages in F. oxysporum. These findings put the evolution of fungal pathogenicity into a new perspective.
