Living apart together: crosstalk between the core and supernumerary genomes in a fungal plant pathogen

BMC Genomics

Research Article

Geert Haesaert¹  Kris Audenaert¹  Adriaan Vanheule²  Sarah De Saeger³  Monica Höfte⁴  Sven Warris⁵  Cees Waalwijk⁵  Elio Schijlen⁵  Theo van der Lee⁵  Henri van de Geest⁵ 

[1] Department of Applied Biosciences, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium;Department of Applied Biosciences, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium;Wageningen UR, Wageningen, The Netherlands;Department of Bioanalysis, Faculty of Pharmaceutical Sciences, Ghent University, Ghent, Belgium;Department of Crop Protection, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium;Wageningen UR, Wageningen, The Netherlands;

关键词: Single-molecule real-time sequencing;    Supernumerary chromosomes;    Fusarium;    Repeat-induced point mutation;    Translocation;    Gene duplications;    Transposable elements;   

DOI  :  10.1186/s12864-016-2941-6

 received in 2016-01-30, accepted in 2016-07-14,  发布年份 2016

来源: Springer

【 摘 要 】

BackgroundEukaryotes display remarkable genome plasticity, which can include supernumerary chromosomes that differ markedly from the core chromosomes. Despite the widespread occurrence of supernumerary chromosomes in fungi, their origin, relation to the core genome and the reason for their divergent characteristics are still largely unknown. The complexity of genome assembly due to the presence of repetitive DNA partially accounts for this.ResultsHere we use single-molecule real-time (SMRT) sequencing to assemble the genome of a prominent fungal wheat pathogen, Fusarium poae, including at least one supernumerary chromosome. The core genome contains limited transposable elements (TEs) and no gene duplications, while the supernumerary genome holds up to 25 % TEs and multiple gene duplications. The core genome shows all hallmarks of repeat-induced point mutation (RIP), a defense mechanism against TEs, specific for fungi. The absence of RIP on the supernumerary genome accounts for the differences between the two (sub)genomes, and results in a functional crosstalk between them. The supernumerary genome is a reservoir for TEs that migrate to the core genome, and even large blocks of supernumerary sequence (>200 kb) have recently translocated to the core. Vice versa, the supernumerary genome acts as a refuge for genes that are duplicated from the core genome.ConclusionsFor the first time, a mechanism was determined that explains the differences that exist between the core and supernumerary genome in fungi. Different biology rather than origin was shown to be responsible. A “living apart together” crosstalk exists between the core and supernumerary genome, accelerating chromosomal and organismal evolution.

【 授权许可】

CC BY   
© The Author(s). 2016