Detection of a transient mitochondrial DNA heteroplasmy in the progeny of crossed genetically divergent isolates of arbuscular mycorrhizal fungi
Detection of a transient mitochondrial DNA heteroplasmy in the progeny of crossed genetically divergent isolates of arbuscular mycorrhizal fungi
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DOI：
10.1111/nph.12372
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发表时间：
2013-10-01
期刊：
影响因子：
9.4
通讯作者：
Hijri, Mohamed
中科院分区：
文献类型：
--
作者：
de la Providencia, Ivan Enrique;Nadimi, Maryam;Hijri, Mohamed
在丛枝菌根真菌（AMF）中，特别是在Rhizophagus irregularis中，已经发现了非自融合和核遗传交换现象。然而，线粒体传递伴随着非自我融合的遗传差异菌株仍然未知。在这里，我们测试的假设，线粒体DNA（mtDNA）异质性发生在孢子的后代，通过交叉遗传差异mtDNA在R。三个地理位置遥远的分离株被用来研究非自身融合和mtDNA传递给后代。我们对两个R. irregularis分离株，并在这些分离株和DAOM-197198的基因间区域开发了分离株特异性大小可变标记。在共生前期和共生期获得了3个杂交组合。每个杂交组合的后代孢子进行基因分型，使用隔离物特异性markers.We发现的证据表明，非自我识别发生在来自不同大陆的菌株在共生前和共生阶段。后代个体孢子的基因分型模式清楚地表明存在两个亲本mtDNA单倍型的标记。我们的研究结果表明，线粒体DNA异质性发生在杂交菌株的后代。然而，这种异质性似乎是一个短暂的阶段，因为所有的活的后代孢子，能够发芽显示只有一个mtDNA单倍型。
Nonself fusion and nuclear genetic exchange have been documented in arbuscular mycorrhizal fungi (AMF), particularly in Rhizophagus irregularis. However, mitochondrial transmission accompanying nonself fusion of genetically divergent isolates remains unknown.Here, we tested the hypothesis that mitochondrial DNA (mtDNA) heteroplasmy occurs in the progeny of spores, obtained by crossing genetically divergent mtDNAs in R. irregularis isolates.Three isolates of geographically distant locations were used to investigate nonself fusions and mtDNA transmission to the progeny. We sequenced two additional mtDNAs of two R. irregularis isolates and developed isolate-specific size-variable markers in intergenic regions of these isolates and those of DAOM-197198. We achieved three crossing combinations in pre-symbiotic and symbiotic phases. Progeny spores per crossing combination were genotyped using isolate-specific markers.We found evidence that nonself recognition occurs between isolates originating from different continents both in pre-symbiotic and symbiotic phases. Genotyping patterns of individual spores from the progeny clearly showed the presence of markers of the two parental mtDNA haplotypes. Our results demonstrate that mtDNA heteroplasmy occurs in the progeny of the crossed isolates. However, this heteroplasmy appears to be a transient stage because all the live progeny spores that were able to germinate showed only one mtDNA haplotype.