Hoshino A, Johzuka-Hisatomi Y, Iida S
National Institute for Basic Biology, Myodaiji, 444-8585, Okazaki, Japan.
Gene. 2001 Mar 7;265(1-2):1-10. doi: 10.1016/s0378-1119(01)00357-2.
We review gene duplication and subsequent structural and functional divergence in the anthocyanin biosynthesis genes in the Japanese and common morning glories and discuss their evolutionary implications. These plants appear to contain at least six copies of the CHS gene and three tandem copies of the DFR gene. Of these, the CHS-D and DFR-B genes are mainly responsible for flower pigmentation and mutations in these genes confer white flowers. We compared the genomic sequences of these duplicated genes between the two morning glories and found small mobile element-like sequences (MELSs) and direct repeats (DRs) in introns and intergenic regions. The results indicate that the MELS elements and DRs play significant roles in divergence after gene duplication. We also discuss DNA rearrangements occurring before and after speciation of these morning glories. DNA transposable elements belonging to the Ac/Ds or En/Spm families have acted as major spontaneous mutagens in these morning glories. We also describe the structural features of the first Mu-related element found in the morning glories and polymorphisms found in the same species.
我们回顾了日本牵牛和普通牵牛中花青素生物合成基因的基因复制以及随后的结构和功能分化，并讨论了它们的进化意义。这些植物似乎含有至少六个拷贝的CHS基因和三个串联拷贝的DFR基因。其中，CHS-D和DFR-B基因主要负责花朵色素沉着，这些基因的突变会导致白花。我们比较了两种牵牛中这些重复基因的基因组序列，在内含子和基因间区域发现了小的类移动元件序列（MELSs）和直接重复序列（DRs）。结果表明，MELS元件和DRs在基因复制后的分化中起重要作用。我们还讨论了这些牵牛物种形成前后发生的DNA重排。属于Ac/Ds或En/Spm家族的DNA转座元件在这些牵牛中充当了主要的自发诱变剂。我们还描述了在牵牛中发现的第一个与Mu相关的元件的结构特征以及在同一物种中发现的多态性。
