南京大学Long Wang等研究人员合作发现，重组和重复诱导的点突变景观揭示Magnaporthe oryzae有性和无性繁殖周期之间的权衡关系。2024年3月13日，《遗传学报》发表了这项成果。

研究人员表示，由Magnaporthe oryzae引起的真菌病是危害全球许多作物的最具破坏性的病害之一。有证据表明，有性生殖对真菌病害有利，因为杂交有利于宿主跳跃。然而，在自然田间观察到的M. oryzae的普遍克隆系却与这一预期相矛盾。更好地了解重组和真菌特异性重复诱导点突变（RIP）在塑造其演化轨迹中的作用，对于弥补这一知识空白至关重要。

研究人员利用来自252个种群样本和92个杂交后代的WGS数据，系统地研究了M. oryzae的RIP和重组景观。数据揭示了RIP可稳健地捕捉M. oryzae的种群历史，并提供了不同M. oryzae支系间重组和RIP率的准确估计。

值得注意的是，这些研究结果凸显了重组率和RIP率的亲本-原生偏倚，这与它们的性潜力和效应蛋白的变化密切相关。这种偏倚表明，在有性生殖周期中产生新的等位基因组合以促进宿主跳跃，与在无性生殖周期中刺激与TE相关的效应蛋白多样化以促进宿主共同演化之间，存在着关键的权衡。这些发现为理解M. oryzae的演化提供了独特的见解。

附：英文原文

Title: Recombination and repeat-induced point mutation landscapes reveal trade-offs between the sexual and asexual cycles of Magnaporthe oryzae

Author: anonymous

Issue&Volume: 2024/03/13

Abstract: The fungal disease caused by Magnaporthe oryzae is one of the most devastating diseases that endangers many crops worldwide. Evidences show that sexual reproduction can be advantageous for fungal diseases as hybridization facilitates host-jumping. However, the pervasive clonal lineages of M. oryzae observed in natural fields contradict this expectation. A better understanding of the roles of recombination and the fungi-specific repeat-induced point (RIP) mutation in shaping its evolutionary trajectory is essential to bridge this knowledge gap. Here we systematically investigate the RIP and recombination landscapes in M. oryzae using WGS data from 252 population samples and 92 cross progenies. Our data reveal that RIP can robustly capture the population history of M. oryzae, and we provide accurate estimations of the recombination and RIP rates across different M. oryzae clades. Significantly, our results highlight a parent-of-origin bias in both recombination and RIP rates, tightly associating with their sexual potential and the variations of effector proteins. This bias suggests a critical trade-off between generating novel allelic combinations in the sexual cycle to facilitate host-jumping and stimulating TE-associated diversification of effectors in the asexual cycle to facilitate host coevolution. These findings provide unique insights for understanding the evolution of blast fungus.

DOI: 10.1016/j.jgg.2024.03.003

Source: https://www.sciencedirect.com/science/article/abs/pii/S1673852724000560