RRC ID 28419
著者 McDonald SM, Plant JN, Worden AZ.
タイトル The mixed lineage nature of nitrogen transport and assimilation in marine eukaryotic phytoplankton: a case study of micromonas.
ジャーナル Mol Biol Evol
Abstract The prasinophyte order Mamiellales contains several widespread marine picophytoplankton (≤ 2 μm diameter) taxa, including Micromonas and Ostreococcus. Complete genome sequences are available for two Micromonas isolates, CCMP1545 and RCC299. We performed in silico analyses of nitrogen transporters and related assimilation genes in CCMP1545 and RCC299 and compared these with other green lineage organisms as well as Chromalveolata, fungi, bacteria, and archaea. Phylogenetic reconstructions of ammonium transporter (AMT) genes revealed divergent types contained within each Mamiellales genome. Some were affiliated with plant and green algal AMT1 genes and others with bacterial AMT2 genes. Land plant AMT2 genes were phylogenetically closer to archaeal transporters than to Mamiellales AMT2 genes. The Mamiellales represent the first green algal genomes to harbor AMT2 genes, which are not found in Chlorella and Chlamydomonas or the chromalveolate algae analyzed but are present in oomycetes. Fewer nitrate transporter (NRT) than AMT genes were identified in the Mamiellales. NRT1 was found in all but CCMP1545 and showed highest similarity to Mamiellales and proteobacterial NRTs. NRT2 genes formed a bootstrap-supported clade basal to other green lineage organisms. Several nitrogen-related genes were colocated, forming a nitrogen gene cluster. Overall, RCC299 showed the most divergent suite of nitrogen transporters within the various Mamiellales genomes, and we developed TaqMan quantitative polymerase chain reaction primer-probes targeting a subset of these, as well as housekeeping genes, in RCC299. All those investigated showed expression either under standard growth conditions or under nitrogen depletion. Like other recent publications, our findings show a higher degree of "mixed lineage gene affiliations" among eukaryotes than anticipated, and even the most phylogenetically anomalous versions appear to be functional. Nitrogen is often considered a regulating factor for phytoplankton populations. This study provides a springboard for exploring the use and functional diversification of inorganic nitrogen transporters and related genes in eukaryotic phytoplankton.
巻・号 27(10)
ページ 2268-83
公開日 2010-10-1
DOI 10.1093/molbev/msq113
PII msq113
PMID 20457585
PMC PMC2944026
MeSH Amino Acid Sequence Archaea / genetics Bacteria / genetics Bayes Theorem Cation Transport Proteins / genetics* Cation Transport Proteins / metabolism Chlorophyta / genetics* Cluster Analysis Computational Biology DNA, Complementary / genetics Eukaryota / genetics Fungi / genetics Gene Expression Profiling Models, Genetic Molecular Sequence Data Nitrogen / metabolism* Phylogeny* Phytoplankton / genetics* Polymerase Chain Reaction / methods Sequence Alignment Species Specificity
IF 11.062
引用数 47
WOS 分野 GENETICS & HEREDITY BIOCHEMISTRY & MOLECULAR BIOLOGY EVOLUTIONARY BIOLOGY
リソース情報
藻類 NIES-2672