New insights from an old mutant: SPADIX4 governs fruiting body development but not hyphal fusion in Sordaria macrospora
New insights from an old mutant: SPADIX4 governs fruiting body development but not hyphal fusion in Sordaria macrospora
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DOI：
10.1007/s00438-016-1258-0
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发表时间：
2016-10
影响因子：
3.1
通讯作者：
I. Teichert;Miriam Lutomski;R. Märker;M. Nowrousian;U. Kück
中科院分区：
文献类型：
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作者：
I. Teichert;Miriam Lutomski;R. Märker;M. Nowrousian;U. Kück
在丝状真菌的有性生活史中，产生多细胞子实体用于孢子的传播。丝状子囊菌Sordaria macrospora作为研究子实体形成的模式系统有很长的历史，已经产生了两个不育突变体的集合。然而，对于大多数这些突变体，潜在的遗传缺陷仍然未知。在这里，我们调查了突变肉穗花序（spd），这是在20世纪50年代通过X射线诱变产生的，并终止性发育后，形成前子实体（原围鞘）。我们对spd基因组进行了测序，发现了一个22 kb的缺失，影响了四个基因，我们将其命名为spd 1 -4。缺失菌株的产生表明，子实体形成仅需要spd 4。虽然大孢链霉菌的不育性常伴随营养菌丝融合缺陷，但Δ spd 4仍具有融合能力。这一特征将SPD 4与许多其他性发育调节因子区分开来。值得注意的是，GFP标记的SPD 4积累在营养菌丝和子实体的起始，子囊孢子线圈的细胞核，但不是在无菌组织从发展中的原子囊壳。我们的研究结果指出，SPD 4子实体形成的一个特定的决定因素。因此，对SPD 4的研究将有助于了解真菌性发育启动过程中的细胞重编程。
During the sexual life cycle of filamentous fungi, multicellular fruiting bodies are generated for the dispersal of spores. The filamentous ascomyceteSordaria macrosporahas a long history as a model system for studying fruiting body formation, and two collections of sterile mutants have been generated. However, for most of these mutants, the underlying genetic defect remains unknown. Here, we investigated the mutant spadix (spd) that was generated by X-ray mutagenesis in the 1950s and terminates sexual development after the formation of pre-fruiting bodies (protoperithecia). We sequenced the spd genome and found a 22 kb deletion affecting four genes, which we termedspd1-4. Generation of deletion strains revealed that onlyspd4is required for fruiting body formation. Although sterility inS. macrosporais often coupled with a vegetative hyphal fusion defect, Δspd4 was still capable of fusion. This feature distinguishes SPD4 from many other regulators of sexual development. Remarkably, GFP-tagged SPD4 accumulated in the nuclei of vegetative hyphae and fruiting body initials, the ascogonial coils, but not in sterile tissue from the developing protoperithecium. Our results point to SPD4 as a specific determinant of fruiting body formation. Research on SPD4 will, therefore, contribute to understanding cellular reprogramming during initiation of sexual development in fungi.