title: The complete chloroplast and mitochondrial genomes of the green macroalga Ulva sp. UNA00071828 (Ulvophyceae, Chlorophyta).
abstract: Sequencing mitochondrial and chloroplast genomes has become an integral part in understanding the genomic machinery and the phylogenetic histories of green algae. Previously, only three chloroplast genomes (Oltmannsiellopsis viridis, Pseudendoclonium akinetum, and Bryopsis hypnoides) and two mitochondrial genomes (O. viridis and P. akinetum) from the class Ulvophyceae have been published. Here, we present the first chloroplast and mitochondrial genomes from the ecologically and economically important marine, green algal genus Ulva. The chloroplast genome of Ulva sp. was 99,983 bp in a circular-mapping molecule that lacked inverted repeats, and thus far, was the smallest ulvophycean plastid genome. This cpDNA was a highly compact, AT-rich genome that contained a total of 102 identified genes (71 protein-coding genes, 28 tRNA genes, and three ribosomal RNA genes). Additionally, five introns were annotated in four genes: atpA (1), petB (1), psbB (2), and rrl (1). The circular-mapping mitochondrial genome of Ulva sp. was 73,493 bp and follows the expanded pattern also seen in other ulvophyceans and trebouxiophyceans. The Ulva sp. mtDNA contained 29 protein-coding genes, 25 tRNA genes, and two rRNA genes for a total of 56 identifiable genes. Ten introns were annotated in this mtDNA: cox1 (4), atp1 (1), nad3 (1), nad5 (1), and rrs (3). Double-cut-and-join (DCJ) values showed that organellar genomes across Chlorophyta are highly rearranged, in contrast to the highly conserved organellar genomes of the red algae (Rhodophyta). A phylogenomic investigation of 51 plastid protein-coding genes showed that Ulvophyceae is not monophyletic, and also placed Oltmannsiellopsis (Oltmannsiellopsidales) and Tetraselmis (Chlorodendrophyceae) closely to Ulva (Ulvales) and Pseudendoclonium (Ulothrichales).
authors: Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487-0345, United States of America.
authors: James T
authors: JT
authors: Melton
authors: Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487-0345, United States of America; Marine Biology Research Group, Department of Biology, Ghent University, Krijgslaan 281-S8, 9000 Ghent, Belgium.
authors: Frederik
authors: F
authors: Leliaert
authors: Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487-0345, United States of America; Smithsonian Marine Station at Fort Pierce, 701 Seaway Drive, Fort Pierce, Florida 34949, United States of America.
authors: Ana
authors: A
authors: Tronholm
authors: Department of Biological Sciences, The University of Alabama, Tuscaloosa, Alabama 35487-0345, United States of America.
authors: Juan M
authors: JM
authors: Lopez-Bautista
mesh_terms: D001483:Base Sequence; D054628:Genome, Chloroplast; D054629:Genome, Mitochondrial; D018745:Genome, Plant; D008969:Molecular Sequence Data; D044445:Ulva / Q000235:genetics*