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Berlin, Germany

Lenz D.,Max Planck Institute of Molecular Plant Physiology | Lenz D.,LGC Genomics GmbH | May P.,University of Luxembourg | May P.,Institute for Systems Biology | Walther D.,Max Planck Institute of Molecular Plant Physiology
BMC Research Notes | Year: 2011

Background: MicroRNA (miRNA) mediated regulation of gene expression has been recognized as a major posttranscriptional regulatory mechanism also in plants. We performed a comparative analysis of miRNAs and their respective gene targets across four plant species: Arabidopsis thaliana (Ath), Medicago truncatula(Mtr), Brassica napus (Bna), and Chlamydomonas reinhardtii (Cre). Results: miRNAs were obtained from mirBase with 218 miRNAs for Ath, 375 for Mtr, 46 for Bna, and 73 for Cre, annotated for each species respectively. miRNA targets were obtained from available database annotations, bioinformatic predictions using RNAhybrid as well as predicted from an analysis of mRNA degradation products (degradome sequencing) aimed at identifying miRNA cleavage products. On average, and considering both experimental and bioinformatic predictions together, every miRNA was associated with about 46 unique gene transcripts with considerably variation across species. We observed a positive and linear correlation between the number miRNAs and the total number of transcripts across different plant species suggesting that the repertoire of miRNAs correlates with the size of the transcriptome of an organism. Conserved miRNA-target pairs were found to be associated with developmental processes and transcriptional regulation, while species-specific (in particular, Ath) pairs are involved in signal transduction and response to stress processes. Conserved miRNAs have more targets and higher expression values than non-conserved miRNAs. We found evidence for a conservation of not only the sequence of miRNAs, but their expression levels as well. Conclusions: Our results support the notion of a high birth and death rate of miRNAs and that miRNAs serve many species specific functions, while conserved miRNA are related mainly to developmental processes and transcriptional regulation with conservation operating at both the sequence and expression level. © 2010 Walther et al; licensee BioMed Central Ltd. Source


Shen H.,Humboldt University of Berlin | Shen H.,Nanjing Agricultural University | Braband A.,Humboldt University of Berlin | Braband A.,LGC Genomics GmbH | Scholtz G.,Humboldt University of Berlin
Journal of Zoological Systematics and Evolutionary Research | Year: 2015

We sequenced the complete mitogenomes of three species of Decapoda, Astacidea, comprising Astacida (freshwater crayfish) and Homarida (marine clawed lobsters): 1. Procambarus fallax f. virginalis (Astacida, Astacoidea), 2. Homarus gammarus (Homarida, Nephropoidea) and 3. Enoplometopus occidentalis (Homarida, Enoplometopoidea). Together with the available species in GenBank, the taxon Astacidea is covered with at least one representative for each of the four main subtaxa. Astacidea show unexpectedly diverse genomic organizations. Ten different gene arrangements have been observed in the 28 investigated species. Compared with the decapod ground pattern, a huge inversion, involving more than half of the mitogenome, has been found in four freshwater crayfish species of Astacoidea and convergently in one lobster species. Surprisingly, this inversion can also be observed in the distantly related Priapulida. This multiple convergent evolution suggests a relative ease in the evolution of great similarities in mitochondrial gene order. In addition, a partial or complete loss of the protein-coding gene nad2 has been found in E. occidentalis and H. gammarus but not in Nephrops norvegicus, Homarus americanus and Enoplometopus debelius. A reversal of the strand asymmetry has been found in five astacideans which is supposed to be caused by the inversion of a replication origin in the control region. © 2015 Blackwell Verlag GmbH. Source


Meier-Kolthoff J.P.,Leibniz Institute DSMZ German Collection of Microorganisms and Cell Cultures | Hahnke R.L.,Leibniz Institute DSMZ German Collection of Microorganisms and Cell Cultures | Petersen J.,Leibniz Institute DSMZ German Collection of Microorganisms and Cell Cultures | Scheuner C.,Leibniz Institute DSMZ German Collection of Microorganisms and Cell Cultures | And 16 more authors.
Standards in Genomic Sciences | Year: 2014

Although Escherichia coli is the most widely studied bacterial model organism and often considered to be the model bacterium per se, its type strain was until now forgotten from microbial genomics. As a part of the Genomic Encyclopedia of Bacteria and Archaea project, we here describe the features of E. coli DSM 30083T together with its genome sequence and annotation as well as novel aspects of its phenotype. The 5,038,133 bp containing genome sequence includes 4,762 protein-coding genes and 175 RNA genes as well as a single plasmid. Affiliation of a set of 250 genome-sequenced E. coli strains, Shigella and outgroup strains to the type strain of E. coli was investigated using digital DNA:DNA-hybridization (dDDH) similarities and differences in genomic G+C content. As in the majority of previous studies, results show Shigella spp. embedded within E. coli and in most cases forming a single subgroup of it. Phylogenomic trees also recover the proposed E. coli phylotypes as monophyla with minor exceptions and place DSM 30083T in phylotype B2 with E. coli S88 as its closest neighbor. The widely used lab strain K-12 is not only genomically but also physiologically strongly different from the type strain. The phylotypes do not express a uniform level of character divergence as measured using dDDH, however, thus an alternative arrangement is proposed and discussed in the context of bacterial subspecies. Analyses of the genome sequences of a large number of E. coli strains and of strains from > 100 other bacterial genera indicate a value of 79-80% dDDH as the most promising threshold for delineating subspecies, which in turn suggests the presence of five subspecies within E. coli. © 2014 Meier-Kolthoff et al.; licensee BioMed Central Ltd. Source


Kuppusamy T.,University of Western Australia | Giavalisco P.,Max Planck Institute of Molecular Plant Physiology | Arvidsson S.,Max Planck Institute of Molecular Plant Physiology | Arvidsson S.,LGC Genomics GmbH | And 7 more authors.
Plant Physiology | Year: 2014

Hakea prostrata (Proteaceae) is adapted to severely phosphorus-impoverished soils and extensively replaces phospholipids during leaf development. We investigated how polar lipid profiles change during leaf development and in response to external phosphate supply. Leaf size was unaffected by a moderate increase in phosphate supply. However, leaf protein concentration increased by more than 2-fold in young and mature leaves, indicating that phosphate stimulates protein synthesis. Orthologs of known lipid-remodeling genes in Arabidopsis (Arabidopsis thaliana) were identified in the H. prostrata transcriptome. Their transcript profiles in young and mature leaves were analyzed in response to phosphate supply alongside changes in polar lipid fractions. In young leaves of phosphate-limited plants, phosphatidylcholine/phosphatidylethanolamine and associated transcript levels were higher, while phosphatidylglycerol and sulfolipid levels were lower than in mature leaves, consistent with low photosynthetic rates and delayed chloroplast development. Phosphate reduced galactolipid and increased phospholipid concentrations in mature leaves, with concomitant changes in the expression of only four H. prostrata genes, GLYCEROPHOSPHODIESTER PHOSPHODIESTERASE1, N-METHYLTRANSFERASE2, NONSPECIFIC PHOSPHOLIPASE C4, and MONOGALACTOSYLDIACYLGLYCEROL3. Remarkably, phosphatidylglycerol levels decreased with increasing phosphate supply and were associated with lower photosynthetic rates. Levels of polar lipids with highly unsaturated 32:x (x = number of double bonds in hydrocarbon chain) and 34:x acyl chains increased.We conclude that a regulatory network with a small number of central hubs underpins extensive phospholipid replacement during leaf development in H. prostrata. This hardwired regulatory framework allows increased photosynthetic phosphorus use efficiency and growth in a low-phosphate environment. This may have rendered H. prostrata lipid metabolism unable to adjust to higher internal phosphate concentrations. © 2014 American Society of Plant Biologists. All rights reserved. Source


Bernt M.,University of Leipzig | Braband A.,LGC Genomics GmbH | Schierwater B.,ITZ | Schierwater B.,American Museum of Natural History | And 6 more authors.
Molecular Phylogenetics and Evolution | Year: 2013

Many years of extensive studies of metazoan mitochondrial genomes have established differences in gene arrangements and genetic codes as valuable phylogenetic markers. Understanding the underlying mechanisms of replication, transcription and the role of the control regions which cause e.g. different gene orders is important to assess the phylogenetic signal of such events. This review summarises and discusses, for the Metazoa, the general aspects of mitochondrial transcription and replication with respect to control regions as well as several proposed models of gene rearrangements. As whole genome sequencing projects accumulate, more and more observations about mitochondrial gene transfer to the nucleus are reported. Thus occurrence and phylogenetic aspects concerning nuclear mitochondrial-like sequences (NUMTS) is another aspect of this review. © 2012 Elsevier Inc. Source

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