Department of Life Sciences, Chromosome Research Institute, Sahmyook University, Seoul, 01795, Republic of Korea.
Department of Plant Science, Plant Genomics and Breeding Institute, Research Institute for Agriculture and Life Sciences, College of Agriculture and Life Sciences, Seoul National University, Seoul, 151-921, Republic of Korea.
Genes Genomics. 2019 Jul;41(7):839-847. doi: 10.1007/s13258-019-00786-x. Epub 2019 Mar 22.
The family Araliaceae contains many medicinal species including ginseng of which the whole genome sequencing analyses have been going on these days.
To characterize the chromosomal distribution of 5S and 45S rDNAs and telomeric repeat in four ginseng related species of Aralia elata (Miq.) Seem., Dendropanax morbiferus H. Lév., Eleutherococcus sessiliflorus (Rupr. Et Maxim.) Seem., Kalopanax septemlobus (Thunb. ex A.Murr.) Koidz.
Pre-labelled oligoprobe (PLOP)-fluorescence in situ hybridization (FISH) was carried out.
The chromosome number of A. elata was 2n = 24, whereas that of the other three species of D. morbiferus, E. sessiliflorus, and K. septemlobus was 2n = 48, corresponding to diploid and tetraploid, respectively, based on the basic chromosome number x = 12 in Araliaceae. In all four species, one pair of 5S signals were detected in the proximal regions of the short arms of chromosome 3, whereas in K. septemlobus, the 5S rDNA signals localized in the subtelomeric region of short arm of chromosome 3, while all the 45S rDNA signals localized at the paracentromeric region of the short arm of chromosome 1. And the telomeric repeat signals were detected at the telomeric region of both short and long arms of most chromosomes.
The PLOP-FISH was very effective compared with conventional FISH method. These results provide useful comparative cytogenetic information to better understand the genome structure of each species and will be useful to trace the history of ginseng genomic constitution.
五加科包含许多药用物种，包括人参，目前正在对其进行全基因组测序分析。
研究刺五加（Aralia elata (Miq.) Seem.）、楤木（Dendropanax morbiferus H. Lév.）、无梗五加（Eleutherococcus sessiliflorus (Rupr. Et Maxim.) Seem.）和轮叶八宝（Kalopanax septemlobus (Thunb. ex A.Murr.) Koidz.）这四种人参近缘种的 5S 和 45S rDNAs 及端粒重复序列在染色体上的分布特征。
采用预标记寡核苷酸探针（PLOP）-荧光原位杂交（FISH）技术。
刺五加的染色体数为 2n = 24，而楤木、无梗五加和轮叶八宝的染色体数分别为 2n = 48，这与五加科的基本染色体数 x = 12 相对应，表明这三种植物分别为二倍体和四倍体。在这四种植物中，一对 5S 信号都定位于第 3 号染色体短臂的近侧区域，而在轮叶八宝中，5S rDNA 信号定位于第 3 号染色体短臂的亚端粒区，所有的 45S rDNA 信号都定位于第 1 号染色体短臂的着丝粒区。端粒重复序列信号则定位于大多数染色体的短臂和长臂的端粒区。
与常规 FISH 方法相比，PLOP-FISH 非常有效。这些结果为更好地了解每个物种的基因组结构提供了有用的比较细胞遗传学信息，并且有助于追踪人参基因组组成的历史。
