Birth of Four Chimeric Plastid Gene Clusters in Japanese Umbrella Pine.
Many genes in the plastid genomes (plastomes) of plants are organized as gene clusters, in which genes are co-transcribed, resembling bacterial operons. These plastid operons are highly conserved, even among conifers, whose plastomes are highly rearranged relative to other seed plants. We have determined the complete plastome sequence of Sciadopitys verticillata (Japanese umbrella pine), the sole member of Sciadopityaceae. The Sciadopitys plastome is characterized by extensive inversions, pseudogenization of four tRNA genes after tandem duplications, and a unique pair of 370-bp inverted repeats involved in the formation of isomeric plastomes. We showed that plastomic inversions in Sciadopitys have led to shuffling of the remote conserved operons, resulting in the birth of four chimeric gene clusters. Our data also demonstrated that the relocated genes can be co-transcribed in these chimeric gene clusters. The plastome of Sciadopitys advances our current understanding of how the conifer plastomes have evolved toward increased diversity and complexity.
Biodiversity Research Center, Academia Sinica, Nankang District, Taipei 11529, Taiwan Genome and Systems Biology Degree Program, National Taiwan University & Academia Sinica, Daan District, Taipei 10617, Taiwan.
Chih-Yao
CY
Hsu
Biodiversity Research Center, Academia Sinica, Nankang District, Taipei 11529, Taiwan.
Chung-Shien
CS
Wu
Biodiversity Research Center, Academia Sinica, Nankang District, Taipei 11529, Taiwan smchaw@sinca.edu.tw.
Shu-Miaw
SM
Chaw
D018744:DNA, Plant / Q000235:genetics; D019143:Evolution, Molecular; D054627:Genome, Plastid / Q000235:genetics*; D055029:Inverted Repeat Sequences / Q000235:genetics; D005810:Multigene Family; D010802:Phylogeny; D028223:Pinus / Q000235:genetics*; D018087:Plastids / Q000235:genetics; D012343:RNA, Transfer / Q000235:genetics*
D018744:DNA, Plant; D012343:RNA, Transfer
conifer; evolution; gene cluster; plastome; rearrangement