scholarly journals A Magnesium Transport Protein Related to Mammalian SLC41 and Bacterial MgtE Contributes to Circadian Timekeeping in a Unicellular Green Alga

Genes ◽  
2019 ◽  
Vol 10 (2) ◽  
pp. 158
Author(s):  
Helen K. Feord ◽  
Frederick E.G. Dear ◽  
Darren J. Obbard ◽  
Gerben van Ooijen
Keyword(s):  
Translational Regulation ◽  
Feedback Loops ◽  
Magnesium Ions ◽  
Sequence Analyses ◽  
Clock Period ◽  
Clock Model ◽  
Ostreococcus Tauri ◽  
Unicellular Green Alga ◽  
Taxonomic Groups ◽  
Daily Changes

Circadian clocks in eukaryotes involve both transcriptional-translational feedback loops, post-translational regulation, and metabolic, non-transcriptional oscillations. We recently identified the involvement of circadian oscillations in the intracellular concentrations of magnesium ions (Mg2+i) that were conserved in three eukaryotic kingdoms. Mg2+i in turn contributes to transcriptional clock properties of period and amplitude, and can function as a zeitgeber to define phase. However, the mechanism—or mechanisms—responsible for the generation of Mg2+i oscillations, and whether these are functionally conserved across taxonomic groups, remain elusive. We employed the cellular clock model Ostreococcus tauri to provide a first study of an MgtE domain-containing protein in the green lineage. OtMgtE shares homology with the mammalian SLC41A1 magnesium/sodium antiporter, which has previously been implicated in maintaining clock period. Using genetic overexpression, we found that OtMgtE contributes to both timekeeping and daily changes in Mg2+i. However, pharmacological experiments and protein sequence analyses indicated that critical differences exist between OtMgtE and either the ancestral MgtE channel or the mammalian SLC41 antiporters. We concluded that even though MgtE domain-containing proteins are only distantly related, these proteins retain a shared role in contributing to cellular timekeeping and the regulation of Mg2+i.

scholarly journals Genome-Wide Analysis of Core Cell Cycle Genes in the Unicellular Green Alga Ostreococcus tauri

2004 ◽  
Vol 22 (3) ◽  
pp. 589-597 ◽  
Author(s):  
Steven Robbens ◽  
Basheer Khadaroo ◽  
Alain Camasses ◽  
Evelyne Derelle ◽  
Conchita Ferraz ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Green Alga ◽  
Genome Wide Analysis ◽  
Cell Cycle Genes ◽  
Ostreococcus Tauri ◽  
Genome Wide ◽  
Unicellular Green Alga

scholarly journals Combining Nanopore and Illumina Sequencing Permits Detailed Analysis of Insertion Mutations and Structural Variations Produced by PEG-Mediated Transformation in Ostreococcus tauri

2021 ◽  
Author(s):  
Julie Thomy ◽  
Frederic Sanchez ◽  
Marta Gut ◽  
Fernando Cruz ◽  
Tyler Alioto ◽  
...  
Keyword(s):  
Insertional Mutagenesis ◽  
Chromosomal Rearrangements ◽  
Molecular Techniques ◽  
End Joining ◽  
Structural Variations ◽  
Vector Integration ◽  
Ostreococcus Tauri ◽  
Unicellular Green Alga ◽  
Genomic Studies ◽  
Non Homologous End Joining

Ostreococcus tauri is a simple unicellular green alga representing an ecologically important group of phytoplankton in oceans worldwide. Modern molecular techniques must be developed in order to understand the mechanisms that permit adaptation of microalgae to their environment. We present for the first time in O. tauri a detailed characterization of individual genomic integration events of foreign DNA of plasmid origin after PEG-mediated transformation. Vector integration appears to be random, occurring mainly at a single locus, and thus confirming the utility of this technique for insertional mutagenesis. While the mechanism of double-stranded DNA repair in the O. tauri model remains to be elucidated, we clearly demonstrate by genome resequencing that the integration of the vector leads to frequent structural variations (deletions/insertions and duplications) and some chromosomal rearrangements in the genome at the insertion loci, and often within the vector sequence itself. From these observations, we speculate that a non-homologous end joining-like mechanism is required during random insertion events, as described in plants and other freshwater algal models. PEG-mediated transformation is therefore a promising molecular biology tool, not only for functional genomic studies, but also for biotechnological research in ecologically important marine algae.

scholarly journals Combining Nanopore and Illumina Sequencing Permits Detailed Analysis of Insertion Mutations and Structural Variations Produced by PEG-Mediated Transformation in Ostreococcus tauri

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 664
Author(s):  
Julie Thomy ◽  
Frederic Sanchez ◽  
Marta Gut ◽  
Fernando Cruz ◽  
Tyler Alioto ◽  
...  
Keyword(s):  
Insertional Mutagenesis ◽  
Chromosomal Rearrangements ◽  
Single Copy ◽  
Molecular Techniques ◽  
End Joining ◽  
Structural Variations ◽  
Vector Integration ◽  
Ostreococcus Tauri ◽  
Unicellular Green Alga ◽  
Genomic Studies

Ostreococcus tauri is a simple unicellular green alga representing an ecologically important group of phytoplankton in oceans worldwide. Modern molecular techniques must be developed in order to understand the mechanisms that permit adaptation of microalgae to their environment. We present for the first time in O. tauri a detailed characterization of individual genomic integration events of foreign DNA of plasmid origin after PEG-mediated transformation. Vector integration occurred randomly at a single locus in the genome and mainly as a single copy. Thus, we confirmed the utility of this technique for insertional mutagenesis. While the mechanism of double-stranded DNA repair in the O. tauri model remains to be elucidated, we clearly demonstrate by genome resequencing that the integration of the vector leads to frequent structural variations (deletions/insertions and duplications) and some chromosomal rearrangements in the genome at the insertion loci. Furthermore, we often observed variations in the vector sequence itself. From these observations, we speculate that a nonhomologous end-joining-like mechanism is employed during random insertion events, as described in plants and other freshwater algal models. PEG-mediated transformation is therefore a promising molecular biology tool, not only for functional genomic studies, but also for biotechnological research in this ecologically important marine alga.

scholarly journals The genome sequence of the colonial chordate, Botryllus schlosseri

eLife ◽  
2013 ◽  
Vol 2 ◽  
Author(s):  
Ayelet Voskoboynik ◽  
Norma F Neff ◽  
Debashis Sahoo ◽  
Aaron M Newman ◽  
Dmitry Pushkarev ◽  
...  
Keyword(s):  
Stem Cell ◽  
Genome Sequence ◽  
High Throughput Sequencing ◽  
Whole Genome Sequence ◽  
Botryllus Schlosseri ◽  
Sequence Analyses ◽  
Homologous Genes ◽  
Novel Method ◽  
Taxonomic Groups ◽  
Eukaryotic Genomes

Botryllus schlosseri is a colonial urochordate that follows the chordate plan of development following sexual reproduction, but invokes a stem cell-mediated budding program during subsequent rounds of asexual reproduction. As urochordates are considered to be the closest living invertebrate relatives of vertebrates, they are ideal subjects for whole genome sequence analyses. Using a novel method for high-throughput sequencing of eukaryotic genomes, we sequenced and assembled 580 Mbp of the B. schlosseri genome. The genome assembly is comprised of nearly 14,000 intron-containing predicted genes, and 13,500 intron-less predicted genes, 40% of which could be confidently parceled into 13 (of 16 haploid) chromosomes. A comparison of homologous genes between B. schlosseri and other diverse taxonomic groups revealed genomic events underlying the evolution of vertebrates and lymphoid-mediated immunity. The B. schlosseri genome is a community resource for studying alternative modes of reproduction, natural transplantation reactions, and stem cell-mediated regeneration.

Sequential waves of polyadenylation and deadenylation define a translation circuit that drives meiotic progression

2008 ◽  
Vol 36 (4) ◽  
pp. 665-670 ◽  
Author(s):  
Eulàlia Belloc ◽  
Maria Piqué ◽  
Raúl Méndez
Keyword(s):  
Untranslated Region ◽  
Translational Regulation ◽  
Feedback Loops ◽  
Quiescent State ◽  
Cytoplasmic Polyadenylation ◽  
Meiotic Progression ◽  
Negative Feedback Loops ◽  
Positive And Negative Feedback ◽  
Maternal Mrnas ◽  
Combinatorial Code

The maternal mRNAs that drive meiotic progression in oocytes contain short poly(A) tails and it is only when these tails are elongated that translation takes place. Cytoplasmic polyadenylation requires two elements in the 3′-UTR (3′-untranslated region), the hexanucleotide AAUAAA and the CPE (cytoplasmic polyadenylation element), which also participates in the transport and localization, in a quiescent state, of its targets. However, not all CPE-containing mRNAs are activated at the same time during the cell cycle, and polyadenylation is temporally and spatially regulated during meiosis. We have recently deciphered a combinatorial code that can be used to qualitatively and quantitatively predict the translational behaviour of CPE-containing mRNAs. This code defines positive and negative feedback loops that generate waves of polyadenylation and deadenylation, creating a circuit of mRNA-specific translational regulation that drives meiotic progression.

scholarly journals Life-Cycle and Genome of OtV5, a Large DNA Virus of the Pelagic Marine Unicellular Green Alga Ostreococcus tauri

PLoS ONE ◽  
2008 ◽  
Vol 3 (5) ◽  
pp. e2250 ◽  
Author(s):  
Evelyne Derelle ◽  
Conchita Ferraz ◽  
Marie-Line Escande ◽  
Sophie Eychenié ◽  
Richard Cooke ◽  
...  
Keyword(s):  
Life Cycle ◽  
Green Alga ◽  
Dna Virus ◽  
Ostreococcus Tauri ◽  
Unicellular Green Alga

Observations of the Thermal Decomposition of Brucite

1968 ◽  
Vol 26 ◽  
pp. 446-447
Author(s):  
P. L. Burnett ◽  
W. R. Mitchell ◽  
C. L. Houck
Keyword(s):  
Thermal Decomposition ◽  
Magnesium Oxide ◽  
Basal Plane ◽  
Magnesium Ions ◽  
A Value ◽  
Reaction Proceeds

Natural Brucite (Mg(OH)2) decomposes on heating to form magnesium oxide (MgO) having its cubic ﹛110﹜ and ﹛111﹜ planes respectively parallel to the prism and basal planes of the hexagonal brucite lattice. Although the crystal-lographic relation between the parent brucite crystal and the resulting mag-nesium oxide crystallites is well known, the exact mechanism by which the reaction proceeds is still a matter of controversy. Goodman described the decomposition as an initial shrinkage in the brucite basal plane allowing magnesium ions to shift their original sites to the required magnesium oxide positions followed by a collapse of the planes along the original <0001> direction of the brucite crystal. He noted that the (110) diffraction spots of brucite immediately shifted to the positions required for the (220) reflections of magnesium oxide. Gordon observed separate diffraction spots for the (110) brucite and (220) magnesium oxide planes. The positions of the (110) and (100) brucite never changed but only diminished in intensity while the (220) planes of magnesium shifted from a value larger than the listed ASTM d spacing to the predicted value as the decomposition progressed.

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