scholarly journals From molecular manipulation of domesticated Chlamydomonas reinhardtii to survival in nature

eLife ◽  
2018 ◽  
Vol 7 ◽  
Author(s):  
Severin Sasso ◽  
Herwig Stibor ◽  
Maria Mittag ◽  
Arthur R Grossman
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Cell Biology ◽  
Real Life ◽  
Model Organism ◽  
Natural Habitats ◽  
Algal Biotechnology ◽  
Cellular Processes ◽  
Physiological Diversity ◽  
Molecular Manipulation ◽  
Abiotic Interactions

In the mid-20th century, the unicellular and genetically tractable green alga Chlamydomonas reinhardtii was first developed as a model organism to elucidate fundamental cellular processes such as photosynthesis, light perception and the structure, function and biogenesis of cilia. Various studies of C. reinhardtii have profoundly advanced plant and cell biology, and have also impacted algal biotechnology and our understanding of human disease. However, the 'real' life of C. reinhardtii in the natural environment has largely been neglected. To extend our understanding of the biology of C. reinhardtii, it will be rewarding to explore its behavior in its natural habitats, learning more about its abundance and life cycle, its genetic and physiological diversity, and its biotic and abiotic interactions.

scholarly journals Analysis of the Phosphoproteome of Chlamydomonas reinhardtii Provides New Insights into Various Cellular Pathways

2006 ◽  
Vol 5 (3) ◽  
pp. 457-468 ◽  
Author(s):  
Volker Wagner ◽  
Gunther Geßner ◽  
Ines Heiland ◽  
Marc Kaminski ◽  
Susan Hawat ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Metal Ion ◽  
Redox Regulation ◽  
Neutral Loss ◽  
Regulation Of Gene Expression ◽  
Model Organism ◽  
High Yield ◽  
Ionization Mass ◽  
Regulatory Pathways ◽  
Cellular Processes

ABSTRACT The unicellular flagellated green alga Chlamydomonas reinhardtii has emerged as a model organism for the study of a variety of cellular processes. Posttranslational control via protein phosphorylation plays a key role in signal transduction, regulation of gene expression, and control of metabolism. Thus, analysis of the phosphoproteome of C. reinhardtii can significantly enhance our understanding of various regulatory pathways. In this study, we have grown C. reinhardtii cultures in the presence of an inhibitor of Ser/Thr phosphatases to increase the phosphoprotein pool. Phosphopeptides from these cells were enriched by immobilized metal-ion affinity chromatography and analyzed by nano-liquid chromatography-electrospray ionization-mass spectrometry (MS) with MS-MS as well as neutral-loss-triggered MS-MS-MS spectra. In this way, we were able to identify 360 phosphopeptides from 328 different phosphoproteins of C. reinhardtii, thus providing new insights into a variety of cellular processes, including metabolic and signaling pathways. Comparative analysis of the phosphoproteome also yielded new functional information on proteins controlled by redox regulation (thioredoxin target proteins) and proteins of the chloroplast 70S ribosome, the centriole, and especially the flagella, for which 32 phosphoproteins were identified. The high yield of phosphoproteins of the latter correlates well with the presence of several flagellar kinases and indicates that phosphorylation/dephosphorylation represents one of the key regulatory mechanisms of eukaryotic cilia. Our data also provide new insights into certain cilium-related mammalian diseases.

scholarly journals Komagataella phaffii as Emerging Model Organism in Fundamental Research

2021 ◽  
Vol 11 ◽  
Author(s):  
Lukas Bernauer ◽  
Astrid Radkohl ◽  
Leonie Gabriela Katharina Lehmayer ◽  
Anita Emmerstorfer-Augustin
Keyword(s):  
Cell Biology ◽  
Model Organism ◽  
Methylotrophic Yeast ◽  
Sole Source ◽  
Strain Engineering ◽  
Cellular Processes ◽  
Komagataella Phaffii ◽  
Cell Wall Biogenesis ◽  
Fundamental Research ◽  
The Common

Komagataella phaffii (Pichia pastoris) is one of the most extensively applied yeast species in pharmaceutical and biotechnological industries, and, therefore, also called the biotech yeast. However, thanks to more advanced strain engineering techniques, it recently started to gain attention as model organism in fundamental research. So far, the most studied model yeast is its distant cousin, Saccharomyces cerevisiae. While these data are of great importance, they limit our knowledge to one organism only. Since the divergence of the two species 250 million years ago, K. phaffii appears to have evolved less rapidly than S. cerevisiae, which is why it remains more characteristic of the common ancient yeast ancestors and shares more features with metazoan cells. This makes K. phaffii a valuable model organism for research on eukaryotic molecular cell biology, a potential we are only beginning to fully exploit. As methylotrophic yeast, K. phaffii has the intriguing property of being able to efficiently assimilate methanol as a sole source of carbon and energy. Therefore, major efforts have been made using K. phaffii as model organism to study methanol assimilation, peroxisome biogenesis and pexophagy. Other research topics covered in this review range from yeast genetics including mating and sporulation behavior to other cellular processes such as protein secretion, lipid biosynthesis and cell wall biogenesis. In this review article, we compare data obtained from K. phaffii with S. cerevisiae and other yeasts whenever relevant, elucidate major differences, and, most importantly, highlight the big potential of using K. phaffii in fundamental research.

scholarly journals Hydin seek: finding a function in ciliary motility

2007 ◽  
Vol 176 (4) ◽  
pp. 403-404 ◽  
Author(s):  
Elizabeth F. Smith
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Cell Biology ◽  
Model Organism ◽  
Human Diseases ◽  
Unique Role ◽  
Ciliary Motility ◽  
The Past ◽  
Experimental Approaches ◽  
Underlying Mechanisms

One of the most surprising discoveries in cell biology in the past 5–10 years is the number of diverse human diseases that result from defects in ciliary assembly and/or motility, so-called ciliopathies (Badano, J.L., N. Mitsuma, P.L. Beales, and N. Katsanis. 2006. Annu. Rev. Genomics Hum. Genet. 7:125–148). The results presented by Lechtreck and Witman (see p. 473 of this issue) provide yet another example of how work in the model organism Chlamydomonas reinhardtii can reveal important insights into the underlying mechanisms of ciliary assembly/function and the diseases associated with defects in these organelles. By taking advantage of the wide array of experimental approaches C. reinhardtii offers, Lechtreck and Witman determined the precise axonemal location of hydin, a protein that, when mutated, causes hydrocephalus, and defined a unique role for hydin in ciliary motility.

scholarly journals To Divide or Not to Divide? How Deuterium Affects Growth and Division of Chlamydomonas reinhardtii

Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 861
Author(s):  
Veronika Kselíková ◽  
Vilém Zachleder ◽  
Kateřina Bišová
Keyword(s):  
Cell Cycle ◽  
Chlamydomonas Reinhardtii ◽  
Cell Cycle Progression ◽  
Model Organism ◽  
Cycle Progression ◽  
Synchronous Cultures ◽  
Multiple Fission ◽  
First Choice ◽  
High Doses

Extensive in vivo replacement of hydrogen by deuterium, a stable isotope of hydrogen, induces a distinct stress response, reduces cell growth and impairs cell division in various organisms. Microalgae, including Chlamydomonas reinhardtii, a well-established model organism in cell cycle studies, are no exception. Chlamydomonas reinhardtii, a green unicellular alga of the Chlorophyceae class, divides by multiple fission, grows autotrophically and can be synchronized by alternating light/dark regimes; this makes it a model of first choice to discriminate the effect of deuterium on growth and/or division. Here, we investigate the effects of high doses of deuterium on cell cycle progression in C. reinhardtii. Synchronous cultures of C. reinhardtii were cultivated in growth medium containing 70 or 90% D2O. We characterize specific deuterium-induced shifts in attainment of commitment points during growth and/or division of C. reinhardtii, contradicting the role of the “sizer” in regulating the cell cycle. Consequently, impaired cell cycle progression in deuterated cultures causes (over)accumulation of starch and lipids, suggesting a promising potential for microalgae to produce deuterated organic compounds.

scholarly journals Versatile CRISPR/Cas9 Systems for Genome Editing in Ustilago maydis

2021 ◽  
Vol 7 (2) ◽  
pp. 149
Author(s):  
Sarah-Maria Wege ◽  
Katharina Gejer ◽  
Fabienne Becker ◽  
Michael Bölker ◽  
Johannes Freitag ◽  
...  
Keyword(s):  
Genome Editing ◽  
Cell Biology ◽  
Gene Deletion ◽  
Fluorescent Protein ◽  
Point Mutations ◽  
Model Organism ◽  
Ustilago Maydis ◽  
Genomic Locus ◽  
Targeted Gene Deletion ◽  
Molecular Cell Biology

The phytopathogenic smut fungus Ustilago maydis is a versatile model organism to study plant pathology, fungal genetics, and molecular cell biology. Here, we report several strategies to manipulate the genome of U. maydis by the CRISPR/Cas9 technology. These include targeted gene deletion via homologous recombination of short double-stranded oligonucleotides, introduction of point mutations, heterologous complementation at the genomic locus, and endogenous N-terminal tagging with the fluorescent protein mCherry. All applications are independent of a permanent selectable marker and only require transient expression of the endonuclease Cas9hf and sgRNA. The techniques presented here are likely to accelerate research in the U. maydis community but can also act as a template for genome editing in other important fungi.

scholarly journals Learning the distribution of single-cell chromosome conformations in bacteria reveals emergent order across genomic scales

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Joris J. B. Messelink ◽  
Muriel C. F. van Teeseling ◽  
Jacqueline Janssen ◽  
Martin Thanbichler ◽  
Chase P. Broedersz
Keyword(s):  
Single Cell ◽  
Caulobacter Crescentus ◽  
Model Organism ◽  
Super Resolution ◽  
Chromosome Organization ◽  
General Strategy ◽  
Cell Axis ◽  
Cellular Processes ◽  
Emergent Order ◽  
Genomic Clusters

AbstractThe order and variability of bacterial chromosome organization, contained within the distribution of chromosome conformations, are unclear. Here, we develop a fully data-driven maximum entropy approach to extract single-cell 3D chromosome conformations from Hi–C experiments on the model organism Caulobacter crescentus. The predictive power of our model is validated by independent experiments. We find that on large genomic scales, organizational features are predominantly present along the long cell axis: chromosomal loci exhibit striking long-ranged two-point axial correlations, indicating emergent order. This organization is associated with large genomic clusters we term Super Domains (SuDs), whose existence we support with super-resolution microscopy. On smaller genomic scales, our model reveals chromosome extensions that correlate with transcriptional and loop extrusion activity. Finally, we quantify the information contained in chromosome organization that may guide cellular processes. Our approach can be extended to other species, providing a general strategy to resolve variability in single-cell chromosomal organization.

scholarly journals Mask R-CNN Based C. Elegans Detection with a DIY Microscope

Biosensors ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 257
Author(s):  
Sebastian Fudickar ◽  
Eike Jannik Nustede ◽  
Eike Dreyer ◽  
Julia Bornhorst
Keyword(s):  
Cell Biology ◽  
High Throughput Screening ◽  
Low Cost ◽  
Image Acquisition ◽  
Rapid Development ◽  
Model Organism ◽  
Large Data ◽  
Data Set ◽  
C Elegans ◽  
Do It Yourself

Caenorhabditis elegans (C. elegans) is an important model organism for studying molecular genetics, developmental biology, neuroscience, and cell biology. Advantages of the model organism include its rapid development and aging, easy cultivation, and genetic tractability. C. elegans has been proven to be a well-suited model to study toxicity with identified toxic compounds closely matching those observed in mammals. For phenotypic screening, especially the worm number and the locomotion are of central importance. Traditional methods such as human counting or analyzing high-resolution microscope images are time-consuming and rather low throughput. The article explores the feasibility of low-cost, low-resolution do-it-yourself microscopes for image acquisition and automated evaluation by deep learning methods to reduce cost and allow high-throughput screening strategies. An image acquisition system is proposed within these constraints and used to create a large data-set of whole Petri dishes containing C. elegans. By utilizing the object detection framework Mask R-CNN, the nematodes are located, classified, and their contours predicted. The system has a precision of 0.96 and a recall of 0.956, resulting in an F1-Score of 0.958. Considering only correctly located C. elegans with an [email protected] IoU, the system achieved an average precision of 0.902 and a corresponding F1 Score of 0.906.

scholarly journals The organisation and functions of local Ca2+ signals

2001 ◽  
Vol 114 (12) ◽  
pp. 2213-2222 ◽  
Author(s):  
Martin D. Bootman ◽  
Peter Lipp ◽  
Michael J. Berridge
Keyword(s):  
Cell Proliferation ◽  
Gene Transcription ◽  
Cell Biology ◽  
Building Blocks ◽  
Cell Types ◽  
Diverse Range ◽  
Cellular Processes ◽  
Different Cell Types ◽  
Intracellular Messenger ◽  
Sensory Mechanisms

Calcium (Ca2+) is a ubiquitous intracellular messenger, controlling a diverse range of cellular processes, such as gene transcription, muscle contraction and cell proliferation. The ability of a simple ion such as Ca2+ to play a pivotal role in cell biology results from the facility that cells have to shape Ca2+ signals in space, time and amplitude. To generate and interpret the variety of observed Ca2+ signals, different cell types employ components selected from a Ca2+ signalling ‘toolkit’, which comprises an array of homeostatic and sensory mechanisms. By mixing and matching components from the toolkit, cells can obtain Ca2+ signals that suit their physiology. Recent studies have demonstrated the importance of local Ca2+ signals in defining the specificity of the interaction of Ca2+ with its targets. Furthermore, local Ca2+ signals are the triggers and building blocks for larger global signals that propagate throughout cells.

scholarly journals The Road Less Traveled? Unconventional Protein Secretion at Parasite–Host Interfaces

2021 ◽  
Vol 9 ◽  
Author(s):  
Erina A. Balmer ◽  
Carmen Faso
Keyword(s):  
Protein Secretion ◽  
Cell Biology ◽  
Mammalian Cells ◽  
Cell Model ◽  
Signal Sequence ◽  
Model Organism ◽  
Secreted Proteins ◽  
Current Status ◽  
Secretory Proteins ◽  
Secretion Pathways

Protein secretion in eukaryotic cells is a well-studied process, which has been known for decades and is dealt with by any standard cell biology textbook. However, over the past 20 years, several studies led to the realization that protein secretion as a process might not be as uniform among different cargos as once thought. While in classic canonical secretion proteins carry a signal sequence, the secretory or surface proteome of several organisms demonstrated a lack of such signals in several secreted proteins. Other proteins were found to indeed carry a leader sequence, but simply circumvent the Golgi apparatus, which in canonical secretion is generally responsible for the modification and sorting of secretory proteins after their passage through the endoplasmic reticulum (ER). These alternative mechanisms of protein translocation to, or across, the plasma membrane were collectively termed “unconventional protein secretion” (UPS). To date, many research groups have studied UPS in their respective model organism of choice, with surprising reports on the proportion of unconventionally secreted proteins and their crucial roles for the cell and survival of the organism. Involved in processes such as immune responses and cell proliferation, and including far more different cargo proteins in different organisms than anyone had expected, unconventional secretion does not seem so unconventional after all. Alongside mammalian cells, much work on this topic has been done on protist parasites, including genera Leishmania, Trypanosoma, Plasmodium, Trichomonas, Giardia, and Entamoeba. Studies on protein secretion have mainly focused on parasite-derived virulence factors as a main source of pathogenicity for hosts. Given their need to secrete a variety of substrates, which may not be compatible with canonical secretion pathways, the study of mechanisms for alternative secretion pathways is particularly interesting in protist parasites. In this review, we provide an overview on the current status of knowledge on UPS in parasitic protists preceded by a brief overview of UPS in the mammalian cell model with a focus on IL-1β and FGF-2 as paradigmatic UPS substrates.

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