Ceratocystis fimbriata is a host specific fungal pathogen of sweet potato (Ipomoea batatas). The closely related species, C. manginecans, is an important pathogen of trees (e.g. Acacia mangium and Mangifera indica) but has never been isolated from tuber crops. The genetic factors that determine the host range and host specificity of these species have not been determined. The aim of this study was to compare the genomes of C. fimbriata and C. manginecans in order to identify species-specific genetic differences that could be associated with host specificity. This included whole-genome alignments as well as comparisons of gene content and transposable elements (TEs). The genomes of the two species were found to be very similar, sharing similar catalogues of CAZymes, peptidases and lipases. However, the genomes of the two species also varied, harbouring species-specific genes (e.g. small secreted effectors, nutrient processing proteins and stress response proteins). A portion of the TEs identified (17%) had a unique distribution in each species. Transposable elements appeared to have played a prominent role in the divergence of the two species because they were strongly associated with chromosomal translocations and inversions as well as with unique genomic regions containing species-specific genes. Two large effector clusters, with unique TEs in each species, were identified. These effectors displayed non-synonymous mutations and deletions, conserved within a species, and could serve as mutational hot-spots for the development of host specificity in the two species.

Ceratocystis fimbriata是甘薯 ( Ipomoea batatas )的宿主特异性真菌病原体。密切相关的物种C. manginecans是树木（例如Acacia mangium和Mangifera indica）的重要病原体，但从未从块茎作物中分离出来。决定这些物种的宿主范围和宿主特异性的遗传因素尚未确定。本研究的目的是比较C. fimbriata和C. manginecans的基因组以确定可能与宿主特异性相关的物种特异性遗传差异。这包括全基因组比对以及基因含量和转座因子 (TE) 的比较。发现这两个物种的基因组非常相似，共享类似的 CAZymes、肽酶和脂肪酶目录。然而，这两个物种的基因组也各不相同，包含物种特异性基因（例如小分泌效应蛋白、营养加工蛋白和应激反应蛋白）。确定的一部分 TE (17%) 在每个物种中都有独特的分布。转座因子似乎在两个物种的分化中发挥了重要作用，因为它们与染色体易位和倒位以及包含物种特异性基因的独特基因组区域密切相关。确定了两个大型效应簇，每个物种具有独特的 TE。这些效应子显示出非同义突变和缺失，在一个物种内是保守的，并且可以作为两个物种宿主特异性发展的突变热点。