Palmer J D, Herbon L A
Department of Biology, University of Michigan, Ann Arbor 48109.
J Mol Evol. 1988;28(1-2):87-97. doi: 10.1007/BF02143500.
We examined the tempo and mode of mitochondrial DNA (mtDNA) evolution in six species of crucifers from two genera, Brassica and Raphanus. The six mtDNAs have undergone numerous internal rearrangements and therefore differ dramatically with respect to the sizes of their subgenomic circular chromosomes. Between 3 and 14 inversions must be postulated to account for the structural differences found between any two species. In contrast, these mtDNAs are extremely similar in primary sequence, differing at only 1-8 out of every 1000 bp. The point mutation rate in these plant mtDNAs is roughly 4 times slower than in land plant chloroplast DNA (cpDNA) and 100 times slower than in animal mtDNA. Conversely, the rate of rearrangements is extraordinarily faster in plant mtDNA than in cpDNA and animal mtDNA.
我们研究了来自芸苔属（Brassica）和萝卜属（Raphanus）两个属的六种十字花科植物中线粒体DNA（mtDNA）的进化节奏和模式。这六种mtDNA经历了大量的内部重排，因此它们的亚基因组环状染色体大小差异很大。必须假定在任意两个物种之间存在3至14次倒位，才能解释所发现的结构差异。相比之下，这些mtDNA的一级序列极其相似，每1000个碱基中只有1至8个不同。这些植物mtDNA中的点突变率大约比陆地植物叶绿体DNA（cpDNA）慢4倍，比动物mtDNA慢100倍。相反，植物mtDNA中的重排率比cpDNA和动物mtDNA快得多。
