Forestry & Agricultural Biotechnology Institute (FABI), Department of Biochemistry, Genetics & Microbiology, University of Pretoriagrid.49697.35, Pretoria, South Africa.
Microbiol Spectr. 2022 Oct 26;10(5):e0142522. doi: 10.1128/spectrum.01425-22. Epub 2022 Sep 26.
The and genes are thought to be the master regulators of sexual development in most ascomycete fungi, and they are often essential for this process. In contrast, it has been suggested that the secondary mating-type genes act to calibrate the sexual cycle and can be dispensable. Recent functional characterization of genes such as Aspergillus fumigatus Huntiella omanensis , and Botrytis cinerea has, however, shown that these secondary genes may play more central roles in the sexual pathway and are essential for the production of mature fruiting structures. We used a comparative transcriptome sequencing (RNA-seq) experiment to show that the truncation of in the wood inhabiting residing in the Ceratocystidaceae is associated with the differential expression of approximately 25% of all the genes present in the genome, including the transcriptional regulators , , , , , and . This suggests that MAT1-2-7 may act as a transcription factor and that Δ mutant sterility is the result of layered deregulation of a variety of signaling and developmental pathways. This study is one of only a few that details the functional characterization of a secondary gene in a nonmodel species. Given that this gene is present in other Ceratocystidaceae species and that there are diverse secondary genes present throughout the Pezizomycotina, further investigation into this gene and others like it will provide a clearer understanding of sexual development in these eukaryotes. Secondary mating-type genes are being described almost as quickly as new fungal genomes are being sequenced. Understanding the functions of these genes has lagged behind their description, in part due to limited taxonomic distribution, lack of conserved functional domains, and difficulties with regard to genetic manipulation protocols. This study aimed to address this by investigating a novel mating-type gene, , for which two independent mutant strains were generated in a previous study. We characterized the molecular response to the truncation of this gene in a nonmodel, wood-infecting fungus and showed that it resulted in widespread differential expression throughout the transcriptome of this fungus. This suggests that secondary genes may play a more important role than previously thought. This study also emphasizes the need for further research into the life cycles of nonmodel fungi, which often exhibit unique features that are very different from the systems understood from model species.
MAT1-2-7 基因可能作为转录因子发挥作用，而 Δ 突变体不育是各种信号和发育途径失调的结果。这项研究是少数几个详细描述非模式物种中次要 MAT 基因功能特征的研究之一。鉴于该基因存在于其他 Ceratocystidaceae 物种中，并且在整个 Pezizomycotina 中存在多种不同的次要 MAT 基因，进一步研究该基因及其类似基因将有助于更好地理解这些真核生物的有性生殖发育。
次级交配型基因的描述速度几乎与新真菌基因组测序的速度一样快。这些基因的功能理解落后于它们的描述，部分原因是它们的分类分布有限、缺乏保守的功能结构域以及遗传操作协议方面的困难。本研究旨在通过研究一种新型交配型基因 MAT1-2-7 来解决这个问题，该基因在之前的研究中已经生成了两个独立的突变株。我们对该基因截断在非模式木生真菌中的分子反应进行了表征，并表明它导致了整个真菌转录组中广泛的差异表达。这表明次级 MAT 基因可能比之前认为的更重要。这项研究还强调了需要对非模式真菌的生命周期进行进一步研究，因为它们通常表现出与从模式物种中理解的系统非常不同的独特特征。
