Diatoms are a diverse group of phytoplankton usually dominating areas characterized by rapidly shifting light conditions. Because of their high growth rates and interesting biochemical profile, their biomass is considered for various commercial applications. This study aimed at identifying strains with superior growth in a photobioreactor (PBR) by screening the natural intraspecific diversity of ecotypes isolated from different habitats.
View Article and Find Full Text PDFCarotenoids are pigments that have a range of functions in human health. The carotenoid diatoxanthin is suggested to have antioxidant, anti-inflammatory and chemo-preventive properties. Diatoxanthin is only produced by a few groups of microalgae, where it functions in photoprotection.
View Article and Find Full Text PDFAureochromes (AUREOs) are unique blue light receptors and transcription factors found only in stramenopile algae. While each of the four AUREOs identified in the diatom Phaeodactylum tricornutum may have a specific function, PtAUREO1a has been shown to have a strong impact on overall gene regulation, when light changes from red to blue light conditions. Despite its significance, the molecular mechanism of PtAUREO1a is largely unexplored.
View Article and Find Full Text PDFThe chloroplast signal recognition particle (CpSRP) receptor (CpFTSY) is a component of the CpSRP pathway that post-translationally targets light-harvesting complex proteins (LHCPs) to the thylakoid membranes in plants and green algae containing chloroplasts derived from primary endosymbiosis. In plants, CpFTSY also plays a major role in the co-translational incorporation of chloroplast-encoded subunits of photosynthetic complexes into the thylakoids. This role has not been demonstrated in green algae.
View Article and Find Full Text PDFThe CRISPR/Cas9 system is an RNA-guided sequence-specific genome editing tool, which has been adopted for single or multiple gene editing in a wide range of organisms. When working with gene families with functional redundancy, knocking out multiple genes within the same family may be required to generate a phenotype. In this study, we tested the possibility of exploiting the known tolerance of Cas9 for mismatches between the single-guide RNA (sgRNA) and target site to simultaneously introduce indels in multiple homologous genes in the marine diatom Phaeodactylum tricornutum.
View Article and Find Full Text PDFThe chloroplast signal recognition particle 54 kDa (CpSRP54) protein is a member of the CpSRP pathway known to target proteins to thylakoid membranes in plants and green algae. Loss of CpSRP54 in the marine diatom Phaeodactylum tricornutum lowers the accumulation of a selection of chloroplast-encoded subunits of photosynthetic complexes, indicating a role in the co-translational part of the CpSRP pathway. In contrast to plants and green algae, absence of CpSRP54 does not have a negative effect on the content of light-harvesting antenna complex proteins and pigments in P.
View Article and Find Full Text PDFThe family of chloroplast ALBINO3 (ALB3) proteins function in the insertion and assembly of thylakoid membrane protein complexes. Loss of ALB3b in the marine diatom leads to a striking change of cell color from the normal brown to green. A 75% decrease of the main fucoxanthin-chlorophyll -binding proteins was identified in the strains as the cause of changes in the spectral properties of the mutant cells.
View Article and Find Full Text PDFThe CRISPR/Cas9 technology has opened the possibility for targeted genome editing in various organisms including diatom model organisms. One standard method for delivery of vectors to diatom cells is by biolistic particle bombardment. Recently delivery by conjugation was added to the tool-box.
View Article and Find Full Text PDFDiatoms are major components of phytoplankton and play a key role in the ecology of aquatic ecosystems. These algae are of great scientific importance for a wide variety of research areas, ranging from marine ecology and oceanography to biotechnology. During the last 20 years, the availability of genomic information on selected diatom species and a substantial progress in genetic manipulation, strongly contributed to establishing diatoms as molecular model organisms for marine biology research.
View Article and Find Full Text PDFObjective: The objective of this study was to analyse intraspecific sequence variation of Atlantic cod mitochondrial DNA, based on a comprehensive collection of completely sequenced mitochondrial genomes.
Results: We determined the complete mitochondrial DNA sequence of 124 cod specimens from the eastern and western part of the species' distribution range in the North Atlantic Ocean. All specimens harboured a unique mitochondrial DNA haplotype.
Altern Ther Health Med
May 2018
Context • Approximately 25% of the US population suffers from dry eyes or some abnormality of the exposed ocular surface. Investigation of effective modalities for their management is needed. Objective • The study intended to examine the efficacy of a proprietary, daily, Dry Eye Protocol consisting of daily use of a moist, heated, ocular compress and intake of an omega-3 dietary supplement in treatment of ocular surface disease.
View Article and Find Full Text PDFThe establishment of the CRISPR/Cas9 technology in diatoms ( Hopes , 2016 ; Nymark , 2016 ) enables a simple, inexpensive and effective way of introducing targeted alterations in the genomic DNA of this highly important group of eukaryotic phytoplankton. Diatoms are of interest as model microorganisms in a variety of areas ranging from oceanography to materials science, in nano- and environmental biotechnology, and are presently being investigated as a source of renewable carbon-neutral fuel and chemicals. Here we present a detailed protocol of how to perform CRISPR/Cas9 gene editing of the marine diatom , including: 1) insertion of guide RNA target site in the diatom optimized CRISPR/Cas9 vector (pKS diaCas9-sgRNA), 2) biolistic transformation for introduction of the pKS diaCas9-sgRNA plasmid to cells and 3) a high resolution melting based PCR assay to screen for CRISPR/Cas9 induced mutations.
View Article and Find Full Text PDFHere we report that the CRISPR/Cas9 technology can be used to efficiently generate stable targeted gene mutations in microalgae, using the marine diatom Phaeodactylum tricornutum as a model species. Our vector design opens for rapid and easy adaption of the construct to the target chosen. To screen for CRISPR/Cas9 mutants we employed high resolution melting based PCR assays, mutants were confirmed by sequencing and further validated by functional analyses.
View Article and Find Full Text PDFContext: Recent changes in usage guidelines have created the potential for millions more Americans to be prescribed statin medications. Caution should be advised because the risk of adverse effects of statins may outweigh their benefits and preclude their preventive use for patients without confirmed cardiovascular disease (CVD) who present with elevated blood lipids. However, statins have shown some benefit in primary CVD prevention.
View Article and Find Full Text PDFPhotosynthetic diatoms that live suspended throughout the water column will constantly be swept up and down by vertical mixing. When returned to the photic zone after experiencing longer periods in darkness, mechanisms exist that enable the diatoms both to survive sudden light exposure and immediately utilize the available energy in photosynthesis and growth. We have investigated both the response to prolonged darkness and the re-acclimation to moderate intensity white irradiance (E = 100 µmol m(-2) s(-1)) in the diatom Phaeodactylum tricornutum, using an integrated approach involving global transcriptional profiling, pigment analyses, imaging and photo-physiological measurements.
View Article and Find Full Text PDFExpression and processing of mitochondrial gene transcripts are fundamental to mitochondrial function, but information from early vertebrates like teleost fishes is essentially lacking. We have analyzed mitogenome sequences of ten codfishes (family Gadidae), and provide complete sequences from three new species (Saithe, Pollack and Blue whiting). Characterization of the mitochondrial mRNAs in Saithe and Atlantic cod identified a set of ten poly(A) transcripts, and six UAA stop codons are generated by posttranscriptional polyadenylation.
View Article and Find Full Text PDFSemaphorins, originally identified as axon guidance molecules, have also been implicated in angiogenesis, function of the immune system and cancerous growth. Here we show that deletion of Plexin B2 (Plxnb2), a semaphorin receptor that is expressed both in the pretubular aggregates and the ureteric epithelium in the developing kidney, results in renal hypoplasia and occasional double ureters. The rate of cell proliferation in the ureteric epithelium and consequently the number of ureteric tips are reduced in the kidneys lacking Plexin B2 (Plxnb2-/-).
View Article and Find Full Text PDFObjective: The aim of the study was to investigate whether serum lipopolysaccharide (LPS) activities are associated with the progression of kidney disease in patients with type 1 diabetes.
Research Design And Methods: For this prospective study, we chose 477 Finnish patients with type 1 diabetes, who were followed for 6 years. At the baseline visit, 239 patients had a normal albumin excretion rate (normoalbuminuria) and 238 patients had macroalbuminuria.
Proc Natl Acad Sci U S A
June 2008
Recently, it has been reported that there is a differential subcellular distribution of components of the minor U12-dependent and major U2-dependent spliceosome, and further that the minor spliceosome functions in the cytoplasm. To study the subcellular localization of the snRNA components of both the major and minor spliceosomes, we performed in situ hybridizations with mouse tissues and human cells. In both cases, all spliceosomal snRNAs were nearly exclusively detected in the nucleus, and the minor U11 and U12 snRNAs were further shown to colocalize with U4 and U2, respectively, in human cells.
View Article and Find Full Text PDFInformation technology (IT) is finding its way into daily clinical work. IT is primarily seen as a tool for providing quality of service, cutting costs and promoting efficiency in every aspect of health care, but improvements for patients' safety are also a driving force. IT-solutions can be found both at an administrative and a clinical level, supporting everything from documentation, distribution and storing of patient data to workflows, monitoring and decision making.
View Article and Find Full Text PDFThe humoral immune response to human immunodeficiency virus type 1 (HIV-1) was studied in 25 AIDS patients with CD4 lymphocyte counts of less than 400/mm3. Humoral immune responses against tissue culture adapted strains of HIV-1, and two limited-passage patient isolates were investigated. Total anti-HIV antibody levels were not significantly different between different individuals.
View Article and Find Full Text PDFActa Pharmacol Toxicol (Copenh)
March 1974