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The Complete Plastid Genome Sequence Of Welwitschia Mirabilis: An Unusually Compact Plastome With Accelerated Divergence Rates, Skip R. Mccoy, Jennifer V. Kuehl, Jeffrey L. Boore, Linda A. Raubeson

All Faculty Scholarship for the College of the Sciences

Background

Welwitschia mirabilis is the only extant member of the family Welwitschiaceae, one of three lineages of gnetophytes, an enigmatic group of gymnosperms variously allied with flowering plants or conifers. Limited sequence data and rapid divergence rates have precluded consensus on the evolutionary placement of gnetophytes based on molecular characters. Here we report on the first complete gnetophyte chloroplast genome sequence, from Welwitschia mirabilis, as well as analyses on divergence rates of protein-coding genes, comparisons of gene content and order, and phylogenetic implications.

Results

The chloroplast genome of Welwitschia mirabilis [GenBank: EU342371] is comprised of 119,726 base pairs and exhibits …

Comparative Chloroplast Genomics: Analyses Including New Sequences From The Angiosperms Nuphar Advena And Ranunculus Macranthus, Linda A. Raubeson, Rhiannon Peery, Timothy W. Chumley, Chris Dziubek, H. Matthew Fourcade, Jeffrey L. Boore, Robert K. Jansen

All Faculty Scholarship for the College of the Sciences

Background

The number of completely sequenced plastid genomes available is growing rapidly. This array of sequences presents new opportunities to perform comparative analyses. In comparative studies, it is often useful to compare across wide phylogenetic spans and, within angiosperms, to include representatives from basally diverging lineages such as the genomes reported here: Nuphar advena (from a basal-most lineage) and Ranunculus macranthus (a basal eudicot). We report these two new plastid genome sequences and make comparisons (within angiosperms, seed plants, or all photosynthetic lineages) to evaluate features such as the status of ycf15 and ycf68 as protein coding genes, the distribution …