Spermidine Synthase and Saccharopine Reductase Have Co-Expression Patterns Both in Basidiomycetes with Fusion Form and Ascomycetes with Separate Form
oleh: Yayong Yang, Lei Shi, Xinyu Xu, Jin Wen, Tianyue Xie, Hui Li, Xiaoyu Li, Mengyu Chen, Xinyi Dou, Chengjin Yuan, Hanbing Song, Baogui Xie, Yongxin Tao
| Format: | Article |
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| Diterbitkan: | MDPI AG 2023-03-01 |
Deskripsi
Gene fusion is a process through which two or more distinct genes are fused into a single chimeric gene. Unlike most harmful fusion genes in cancer cells, in this study, we first found that spermidine synthetase- (SPDS, catalyst of spermidine biosynthesis) and saccharopine reductase- (SR, catalyst of the penultimate step of lysine biosynthesis) encoding genes form a natural chimeric gene, <i>FfSpdsSr</i>, in <i>Flammulina filiformis</i>. Through the cloning of full-length ORFs in different strains and the analysis of alternative splicing in developmental stages, <i>FfSpdsSr</i> has only one copy and unique transcript encoding chimeric SPDS-SR in <i>F. filiformis</i>. By an orthologous gene search of <i>SpdsSr</i> in more than 80 fungi, we found that the chimeric <i>SpdsSr</i> exists in basidiomycetes, while the two separate <i>Spds</i> and <i>Sr</i> independently exist in ascomycetes, chytridiomycetes, and oomycetes. Further, the transcript level of <i>FfSpdsSr</i> was investigated in different developmental stages and under some common environmental factors and stresses by RT-qPCR. The results showed that <i>FfSpdsSr</i> mainly up-regulated in the elongation stage and pileus development of <i>F. filiformis</i>, as well as under blue light, high temperature, H<sub>2</sub>O<sub>2</sub>, and MeJA treatments. Moreover, a total of 15 sets of RNA-Seq data, including 218 samples of <i>Neurospora crassa</i>, were downloaded from the GEO database and used to analyze the expression correlation of <i>NcSpds</i> and <i>NcSr</i>. The results showed that the separate <i>NcSpds</i> and <i>NcSr</i> shared highly similar co-expression patterns in the samples with different strains and different nutritional and environmental condition treatments. The chimeric <i>SpdsSr</i> in basidiomycetes and the co-expression pattern of the <i>Spds</i> and <i>Sr</i> in <i>N. crassa</i> indicate the special link of spermidine and lysine in fungi, which may play an important role in the growth and development of fruiting body and in response to the multiple environmental factors and abiotic stresses.