Akagi H, Shimada H, Fujimura T
Plant Biotechnology Laboratory, Life Science Institute, Mitsui Toatsu Chemicals, Inc., Togo 1144, Mobara 297, Japan.
Curr Genet. 1995 Dec;29(1):58-65. doi: 10.1007/BF00313194.
Analyzing more than 100 independent rice cybrids, we found evidence for inter-molecular recombination between parental mitochondrial genomes occurring at high frequency soon after protoplast fusion. The structure of the region around the atp6 gene showed extensive polymorphism among Indica (MTC-5A), Japonica (Nipponbare), and wild abortive (IR58024A) mitochondrial genomes. Recombination between the mitochondrial genomes of IR58024A and MTC-5A around the atp6 gene was detected by Southern-blot analysis of cybrid plants. Such recombinant mitochondrial molecules were also cloned from IR58024A/Nipponbare cybrid callus. PCR analysis around the atp6 gene demonstrated that inter-parental recombination occurs in practically all cybrid calli within 2 weeks after protoplast fusion. At this point, parental and recombinant mitochondrial genomes co-existed within the callus. Over the course of further cultivation, however, mitochondrial genome diversity decreased as parental and/or recombinant genomes segregated out.
通过分析100多个独立的水稻细胞质杂种，我们发现了原生质体融合后不久亲本线粒体基因组之间发生高频分子间重组的证据。atp6基因周围区域的结构在籼稻（MTC - 5A）、粳稻（日本晴）和野败型（IR58024A）线粒体基因组之间表现出广泛的多态性。通过对细胞质杂种植物的Southern杂交分析，检测到IR58024A和MTC - 5A线粒体基因组在atp6基因周围发生了重组。这种重组的线粒体分子也从IR58024A/日本晴细胞质杂种愈伤组织中克隆得到。围绕atp6基因的PCR分析表明，亲本间重组在原生质体融合后2周内几乎在所有细胞质杂种愈伤组织中发生。此时，亲本和重组线粒体基因组在愈伤组织中共存。然而，在进一步培养过程中，随着亲本和/或重组基因组的分离，线粒体基因组多样性降低。
