Institute of Vegetables, Zhejiang Academy of Agricultural Sciences, Hangzhou, 310021, China.
College of Horticulture, Nanjing Agricultural University, Nanjing, 210095, China.
Theor Appl Genet. 2019 Apr;132(4):1223-1233. doi: 10.1007/s00122-018-03274-0. Epub 2019 Feb 13.
We used a mitochondrial (mt) mutant of cucumber to document rare maternal transmission of mt polymorphisms and demonstrate that polymorphisms can become more prevalent and sort to progenies to increase mt DNA diversity. The mitochondrial (mt) DNAs of most angiosperms show maternal inheritance, although relatively rare biparental or paternal transmission has been documented. The mt DNAs of plants in the genus Cucumis (family Cucurbitaceae) are paternally transmitted in intra- and interspecific crosses. MSC16 is an inbred line of cucumber (Cucumis sativus) with a mitochondrially associated mosaic (MSC) phenotype. MSC16 was crossed as the male parent to wild-type cultivar Calypso, and hybrid progenies were evaluated for the wild-type phenotype in order to screen for rare maternal or biparental transmission of the mt DNA. We then used standard and droplet digital (dd) PCR to study the transmission of polymorphic mt markers across three generations. We observed evidence for occasional maternal and biparental transmission of the mt DNA in cucumber. The transmission of specific regions of the maternal mt DNA could be as high as 17.8%, although the amounts of these maternal regions were often much lower relative to paternally transmitted regions. Different combinations of maternal and paternal mt polymorphisms were detected in progenies across generations, indicating that relatively rare maternal regions can be transmitted to progenies and become predominant to increase mt DNA diversity over generations.
我们使用黄瓜的线粒体（mt）突变体来记录罕见的母系 mt 多态性传递，并证明多态性可以变得更为普遍，并通过后代进行分类，从而增加 mtDNA 多样性。尽管已经记录到相对罕见的双亲或父系传递，但大多数被子植物的线粒体（mt）DNA 都表现出母系遗传。植物属中的 mtDNA 黄瓜（葫芦科）在种内和种间杂交中呈父系传递。MSC16 是黄瓜（Cucumis sativus）的自交系，具有与线粒体相关的镶嵌（MSC）表型。MSC16 作为父本与野生型品种 Calypso 杂交，评估杂种后代的野生型表型，以筛选 mtDNA 的罕见母系或双亲传递。然后，我们使用标准和液滴数字（dd）PCR 研究了三代中多态性 mt 标记的传递。我们观察到了黄瓜中 mtDNA 偶尔发生母系和双亲传递的证据。母系 mtDNA 的特定区域的传递率可高达 17.8%，尽管这些母系区域的数量相对于父系传递区域通常要低得多。在不同世代的后代中检测到了母系和父系 mt 多态性的不同组合，这表明相对罕见的母系区域可以传递给后代，并通过后代进行分类，从而增加 mtDNA 多样性。
