TY - JOUR T1 - Signatures of host specialization and a recent transposable element burst in the dynamic one-speed genome of the fungal barley powdery mildew pathogen JF - bioRxiv DO - 10.1101/246280 SP - 246280 AU - Lamprinos Frantzeskakis AU - Barbara Kracher AU - Stefan Kusch AU - Makoto Yoshikawa-Maekawa AU - Saskia Bauer AU - Carsten Pedersen AU - Pietro D Spanu AU - Takaki Maekawa AU - Paul Schulze-Lefert AU - Ralph Panstruga Y1 - 2018/01/01 UR - http://biorxiv.org/content/early/2018/01/11/246280.abstract N2 - Powdery mildews are biotrophic pathogenic fungi infecting a number of economically important plants. The grass powdery mildew, Blumeria graminis, has become a model organism to study host specialization of obligate biotrophic fungal pathogens. We resolved the large-scale genomic architecture of B. graminis forma specialis hordei (Bgh) to explore the potential influence of its genome organization on the co-evolutionary process with its host plant, barley (Hordeum vulgare). The near-chromosome level assemblies of the Bgh reference isolate DH14 and one of the most diversified isolates, RACE1, enabled a comparative analysis of these haploid genomes, which are highly enriched with transposable elements (TEs). We found largely retained genome synteny and gene repertoires, yet detected copy number variation (CNV) of secretion signal peptide-containing protein-coding genes (SPs) and locally disrupted synteny blocks. Genes coding for sequence-related SPs are often locally clustered, but neither the SP clusters nor TEs are enriched in specific genomic regions. Extended comparative analysis with different host-specific B. graminis formae speciales revealed the existence of a core suite of SPs, but also isolate-specific SP sets as well as congruence of SP CNV and phylogenetic relationship. We further detected evidence for a recent, lineage-specific expansion of TEs in the Bgh genome. The characteristics of the Bgh genome (largely retained synteny, CNV of SP genes, recently proliferated TEs and a lack of compartmentalization) are consistent with a “one-speed” genome that differs in its architecture and (co-)evolutionary pattern from the “two-speed” genomes reported for several other filamentous phytopathogens.AbbreviationsAVRavirulence effector geneBghBlumeria graminis f.sp. hordeiCNVcopy number variationCSEPcandidate secreted effector proteinESTexpressed sequence tagFPKMfragments per kilobase [sequence length] and million [sequenced fragments]mtDNAmitochondrial DNASNPsingle nucleotide polymorphismSPsecreted proteinTEtransposable element ER -