Raman Gurusamy, Choi Kyoung Su, Park SeonJoo
Department of Life Sciences, Yeungnam University, Gyeongsan 38541, Korea.
Genes (Basel). 2016 Dec 2;7(12):115. doi: 10.3390/genes7120115.
is a popular ornamental fern cultivated worldwide. Native to the Korean Peninsula, Japan, and Dokdo Island in the Sea of Japan, it is the only fern present on Dokdo Island. We isolated and characterized the chloroplast (cp) genome of , and compared it with those of closely related species. The genes and were found to be present within the cp genome of , whereas and were lacking. Moreover, cp genomes of and lack and , suggesting these are not conserved among angiosperm cp genomes. The deletion of , , and in the cp genomes of and other eupolypod ferns indicates these genes are restricted to tree ferns, non-core leptosporangiates, and basal ferns. The cp genome also encoded and , with GUG start codons that were only conserved in polypod ferns, and it shares two significant inversions with other ferns, including a minor inversion of the region and an approximate 3 kb inversion of the region. Phylogenetic analyses showed that was found to be a sister clade to Psilotales-Ophioglossales with a 100% bootstrap (BS) value. The sister relationship between Pteridaceae and eupolypods was also strongly supported by a 100% BS, but Bayesian molecular clock analyses suggested that diversified in the mid-Paleogene period (45.15 ± 4.93 million years ago) and might have moved from Eurasia to Dokdo Island.
是一种在全球广泛种植的受欢迎的观赏蕨类植物。原产于朝鲜半岛、日本和日本海的独岛，它是独岛上唯一的蕨类植物。我们分离并鉴定了的叶绿体（cp）基因组，并将其与近缘物种的进行了比较。发现基因和存在于的cp基因组中，而和则缺失。此外，和的cp基因组缺乏和，表明这些在被子植物cp基因组中不保守。和其他真多歧蕨类植物的cp基因组中、和的缺失表明这些基因仅限于树蕨、非核心薄囊蕨类和基部蕨类。的cp基因组还编码了和，其起始密码子为GUG，仅在多歧蕨类中保守，并且它与其他蕨类植物有两个显著的倒位，包括区域的一个小倒位和区域的一个约3 kb的倒位。系统发育分析表明，被发现是松叶蕨目-瓶尔小草目（Psilotales - Ophioglossales）的姐妹分支，自展值（BS）为100%。凤尾蕨科（Pteridaceae）和真多歧蕨类之间的姐妹关系也得到了100% BS的有力支持，但贝叶斯分子钟分析表明，在古近纪中期（4515 ± 493万年前）分化，可能从欧亚大陆迁移到了独岛。
