The highly conserved rps12 gene in ferns provides strong evidence for decreased substitution rates in the inverted repeat region

2021 ◽  
Vol 307 (2) ◽  
Author(s):  
Jingyao Ping ◽  
Aimin Li ◽  
Peipei Feng ◽  
Ming Zhu ◽  
Yingjuan Su ◽  
...  
Plants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 397
Author(s):  
Kyoung Su Choi ◽  
Young-Ho Ha ◽  
Hee-Young Gil ◽  
Kyung Choi ◽  
Dong-Kap Kim ◽  
...  

Previous studies on the chloroplast genome in Clematis focused on the chloroplast structure within Anemoneae. The chloroplast genomes of Cleamtis were sequenced to provide information for studies on phylogeny and evolution. Two Korean endemic Clematis chloroplast genomes (Clematis brachyura and C. trichotoma) range from 159,170 to 159,532 bp, containing 134 identical genes. Comparing the coding and non-coding regions among 12 Clematis species revealed divergent sites, with carination occurring in the petD-rpoA region. Comparing other Clematis chloroplast genomes suggested that Clematis has two inversions (trnH-rps16 and rps4), reposition (trnL-ndhC), and inverted repeat (IR) region expansion. For phylogenetic analysis, 71 protein-coding genes were aligned from 36 Ranunculaceae chloroplast genomes. Anemoneae (Anemoclema, Pulsatilla, Anemone, and Clematis) clades were monophyletic and well-supported by the bootstrap value (100%). Based on 70 chloroplast protein-coding genes, we compared nonsynonymous (dN) and synonymous (dS) substitution rates among Clematis, Anemoneae (excluding Clematis), and other Ranunculaceae species. The average synonymoussubstitution rates (dS)of large single copy (LSC), small single copy (SSC), and IR genes in Anemoneae and Clematis were significantly higher than those of other Ranunculaceae species, but not the nonsynonymous substitution rates (dN). This study provides fundamental information on plastid genome evolution in the Ranunculaceae.


1984 ◽  
Vol 62 (7) ◽  
pp. 571-576 ◽  
Author(s):  
David A. Boyd ◽  
Thomas C. Hobman ◽  
Sally A. Gruenke ◽  
Glen R. Klassen

A physical map of the mtDNA (mitochondrial DNA) of Achlya klebsiana has been constructed. The molecule is circular and has a size of 50.7 ± 1.3 kilobases (kb). A large portion of genome exists in the form of an inverted repeat region, each copy being from 9.74 to 10.92 kb in length. Part of the repeat region is homologous to the yeast mitochondrial 21S rRNA gene. Two isomers of the molecule are present owing to a flip–flop rearrangement of the unique regions. Since no restriction-site differences have been detected between the two repeat regions, it is likely that the inverted repeat condition promotes continual sequence conversion, thus preserving the evolutionary advantages of gene duplication. The physical map of A. klebsiana mtDNA was compared with that of Achlya ambisexualis E-87 and it was found that the inverted repeat regions, as well as a 7-kb unique region adjacent to one of the repeat regions, were highly conserved with respect to restriction-site spacing.


Sign in / Sign up

Export Citation Format

Share Document