Aylward Janneke, Havenga Minette, Wingfield Brenda D, Wingfield Michael J, Dreyer Léanne L, Roets Francois, Steenkamp Emma T
Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20 Hatfield, 0028, South Africa; Department of Conservation Ecology and Entomology, Stellenbosch University, Private Bag X1 Matieland, 7602, South Africa.
Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Private Bag X20 Hatfield, 0028, South Africa.
Mol Phylogenet Evol. 2022 Jun;171:107456. doi: 10.1016/j.ympev.2022.107456. Epub 2022 Mar 28.
The mating-type (MAT1) locus encodes transcription factors essential for the onset of the sexual cycle in ascomycete fungi. This locus has been characterised in only a few heterothallic, plant pathogenic Mycosphaerellaceae and Teratosphaeriaceae. We used available genome sequences for Mycosphaerellales species to investigate the presence of two unique mating-type-associated features. The accessory MAT1 genes, MAT1-1-10 (MATORF2) and MAT1-2-12 (MATORF1), typically occurred in both MAT idiomorphs of Mycosphaerellaceae species. In contrast, they were associated with only one idiomorph in Teratosphaeriaceae species. In Pseudocercospora, phylogenetic analyses showed that homologs present in different idiomorphs were paralogous and subject to different selective pressures, indicating that their evolution is linked to mating type. In almost half of the investigated Mycosphaerellales genomes, numerous short fragment sequences, almost identical to portions of the MAT1-1-1 and MAT1-2-1 genes, were present in multiple areas outside of the MAT1 locus. Aligned to the MAT1 genes, these sequences resembled an mRNA transcript. Fragment sequences were similar among species groups and occurred at the same genomic positions, implying that monophyletic groups have the same origins of these sequences. Although the functions of the MAT fragment sequences and accessory MAT1 genes remain unknown, both were expressed in the representative Mycosphaerellaceae and Teratosphaeriaceae species that were investigated.
交配型（MAT1）位点编码子囊菌真菌有性生殖周期起始所必需的转录因子。该位点仅在少数异宗配合的植物病原球腔菌科和球座菌科中得到了表征。我们利用球腔菌目物种的现有基因组序列来研究两个独特的与交配型相关特征的存在情况。辅助MAT1基因MAT1-1-10（MATORF2）和MAT1-2-12（MATORF1）通常存在于球腔菌科物种的两种交配型特异性基因座中。相比之下，它们仅与球座菌科物种的一种交配型特异性基因座相关。在假尾孢属中，系统发育分析表明，不同交配型特异性基因座中存在的同源物是旁系同源物，且受到不同的选择压力，这表明它们的进化与交配型有关。在近一半被研究的球腔菌目基因组中，许多短片段序列与MAT1-1-1和MAT1-2-1基因的部分序列几乎相同，这些序列存在于MAT1位点之外的多个区域。与MAT1基因比对后，这些序列类似于mRNA转录本。片段序列在物种组之间相似，且出现在相同的基因组位置，这意味着单系类群的这些序列有相同的起源。尽管MAT片段序列和辅助MAT1基因的功能尚不清楚，但在被研究的代表性球腔菌科和球座菌科物种中它们均有表达。
