How heat stress drives the expression of LTR retrotransposons in the flatworm model organism Macrostomum lignano

Corals and their endosymbiotic dinoflagellates of the genus Symbiodinium have a fragile relationship that breaks down under heat stress, an event known as bleaching. However, many coral species have adapted to high temperature environments such as the Red Sea (RS). To investigate mechanisms underlying temperature adaptation in zooxanthellate cnidarians we compared transcriptome- and proteome-wide heat stress response (24 h at 32°C) of three strains of the model organism Aiptasia pallida from regions with differing temperature profiles; North Carolina (CC7), Hawaii (H2) and the RS. Correlations between transcript and protein levels were generally low but inter-strain comparisons highlighted a common core cnidarian response to heat stress, including protein folding and oxidative stress pathways. RS anemones showed the strongest increase in antioxidant gene expression and exhibited significantly lower reactive oxygen species (ROS) levels in hospite . However, comparisons of antioxidant gene and protein expression between strains did not show strong differences, indicating similar antioxidant capacity across the strains. Subsequent analysis of ROS production in isolated symbionts confirmed that the observed differences of ROS levels in hospite were symbiont-driven. Our findings indicate that RS anemones do not show increased antioxidant capacity but may have adapted to higher temperatures through association with more thermally tolerant symbionts.

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THE IMPORTANCE OF HSP-25 IN CAENORHABDITIS ELEGANS LONGEVITY

Innovation in Aging ◽

10.1093/geroni/igz038.3176 ◽

2019 ◽

Vol 3 (Supplement_1) ◽

pp. S865-S865

Author(s):

Niaya James ◽

Jessica L Scheirer ◽

Karl Rodriguez

Keyword(s):

Heat Stress ◽

Caenorhabditis Elegans ◽

Heat Shock ◽

Model Organism ◽

Small Heat Shock Protein ◽

Health Science ◽

Science Center ◽

Knock Out ◽

University Of Texas

Abstract Karl A. Rodriguez’s laboratory at the University of Texas Health Science Center, San Antonio, Texas, is interested in the role of small heat shock proteins in the proteostasis network and aging using the model organism, Caenorhabditis elegans. Molecular chaperones facilitate protein folding and improve the degradation activity of the proteasome and autolysosome hence decreasing disease-associated aggregates. Previous work in rodents have shown an increase in expression levels of the small heat shock protein 25 (HSP-25) correlates with maximum lifespan potential. To further explore the role of HSP-25 in C. elegans, two HSP-25 knock-out strains were exposed to a one-hour heat stress, heat shock, and two non-heat stress conditions.

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Transcriptional signatures of somatic neoblasts and germline cells in Macrostomum lignano

eLife ◽

10.7554/elife.20607 ◽

2016 ◽

Vol 5 ◽

Cited By ~ 23

Author(s):

Magda Grudniewska ◽

Stijn Mouton ◽

Daniil Simanov ◽

Frank Beltman ◽

Margriet Grelling ◽

...

Keyword(s):

Gene Expression ◽

Stem Cells ◽

De Novo ◽

Transcriptome Assembly ◽

Model Organism ◽

Proliferating Cells ◽

Macrostomum Lignano ◽

Germline Cells

The regeneration-capable flatworm Macrostomum lignano is a powerful model organism to study the biology of stem cells in vivo. As a flatworm amenable to transgenesis, it complements the historically used planarian flatworm models, such as Schmidtea mediterranea. However, information on the transcriptome and markers of stem cells in M. lignano is limited. We generated a de novo transcriptome assembly and performed the first comprehensive characterization of gene expression in the proliferating cells of M. lignano, represented by somatic stem cells, called neoblasts, and germline cells. Knockdown of a selected set of neoblast genes, including Mlig-ddx39, Mlig-rrm1, Mlig-rpa3, Mlig-cdk1, and Mlig-h2a, confirmed their crucial role for the functionality of somatic neoblasts during homeostasis and regeneration. The generated M. lignano transcriptome assembly and gene expression signatures of somatic neoblasts and germline cells will be a valuable resource for future molecular studies in M. lignano.

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The regenerative flatworm Macrostomum lignano, a model organism with high experimental potential

The International Journal of Developmental Biology ◽

10.1387/ijdb.180077eb ◽

2018 ◽

Vol 62 (6-7-8) ◽

pp. 551-558 ◽

Cited By ~ 5

Author(s):

Stijn Mouton ◽

Jakub Wudarski ◽

Magda Grudniewska ◽

Eugene Berezikov

Keyword(s):

Model Organism ◽

Macrostomum Lignano

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Influence of temperature on the development, reproduction and regeneration in the flatworm model organism Macrostomum lignano

10.1101/389478 ◽

2018 ◽

Cited By ~ 1

Author(s):

Jakub Wudarski ◽

Kirill Ustyantsev ◽

Lisa Glazenburg ◽

Eugene Berezikov

Keyword(s):

Heat Shock ◽

Heat Shock Response ◽

Elevated Temperatures ◽

Model Organism ◽

Response Threshold ◽

Reproduction Rate ◽

Negative Consequences ◽

Time Reproduction ◽

Shock Response ◽

Macrostomum Lignano

AbstractThe free-living marine flatworm Macrostomum lignano is a powerful model organism to study mechanisms of regeneration and stem cell regulation due to its convenient combination of biological and experimental properties, including the availability of transgenesis methods, which is unique among flatworm models. However, due to its relatively recent introduction in research, there are still many biological aspects of the animal that are not known. One of such questions is the influence of the culturing temperature on Macrostomum biology. Here we systematically investigated how different culturing temperatures affect the development time, reproduction rate, regeneration, heat shock response, and gene knockdown efficiency by RNA interference in M. lignano. We used marker transgenic lines of the flatworm to accurately measure the regeneration endpoint and to establish the stress response threshold for temperature shock. We found that compared to the culturing temperature of 20°C commonly used for M. lignano, elevated temperatures of 25°C-30°C substantially speed-up the development and regeneration time and increase reproduction rate without detectable negative consequences for the animal, while temperatures above 30°C elicit a heat shock response.We show that altering the temperature conditions can be used to shorten the time required to establish M. lignano cultures, store important lines and optimize the microinjection procedures for transgenesis. Our findings will help to optimize the design of experiments in M. lignano and thus facilitate future research in this model organism.

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A platform for efficient transgenesis in Macrostomum lignano, a flatworm model organism for stem cell research

10.1101/151654 ◽

2017 ◽

Cited By ~ 1

Author(s):

Jakub Wudarski ◽

Daniil Simanov ◽

Kirill Ustyantsev ◽

Katrien de Mulder ◽

Margriet Grelling ◽

...

Keyword(s):

Stem Cell ◽

Fluorescent Proteins ◽

Model Organism ◽

Promoter Regions ◽

Cell Stage ◽

Genetic Studies ◽

Stem Cell Regulation ◽

Genome Wide ◽

Macrostomum Lignano ◽

Transgenic Lines

ABSTRACTRegeneration-capable flatworms are informative research models to study the mechanisms of stem cell regulation, regeneration and tissue patterning. However, the lack of transgenesis methods significantly hampers their wider use. Here we report development of a transgenesis method for Macrostomum lignano, a basal flatworm with excellent regeneration capacity. We demonstrate that microinjection of DNA constructs into fertilized one-cell stage eggs, followed by a low dose of irradiation, frequently results in random integration of the transgene in the genome and its stable transmission through the germline. To facilitate selection of promoter regions for transgenic reporters, we assembled and annotated the M. lignano genome, including genome-wide mapping of transcription start regions, and showed its utility by generating multiple stable transgenic lines expressing fluorescent proteins under several tissue-specific promoters. The reported transgenesis method and annotated genome sequence will permit sophisticated genetic studies on stem cells and regeneration using M. lignano as a model organism.

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Long terminal repeats (LTR) and transcription factors regulate PHRE1 and PHRE2 activity in Moso bamboo under heat stress

BMC Plant Biology ◽

10.1186/s12870-021-03339-1 ◽

2021 ◽

Vol 21 (1) ◽

Author(s):

Pradeep K. Papolu ◽

Muthusamy Ramakrishnan ◽

Qiang Wei ◽

Kunnummal Kurungara Vinod ◽

Long-Hai Zou ◽

...

Keyword(s):

Transcription Factors ◽

Heat Stress ◽

Transgenic Plants ◽

Promoter Activity ◽

Moso Bamboo ◽

Ltr Retrotransposons ◽

In Planta ◽

Environmental Stress Response ◽

Long Terminal Repeats ◽

Camv35s Promoter

Abstract Background LTR retrotransposons play a significant role in plant growth, genome evolution, and environmental stress response, but their regulatory response to heat stress remains unclear. We have investigated the activities of two LTR retrotransposons, PHRE1 and PHRE2, of moso bamboo (Phyllostachys edulis) in response to heat stress. Results The differential overexpression of PHRE1 and PHRE2 with or without CaMV35s promoter showed enhanced expression under heat stress in transgenic plants. The transcriptional activity studies showed an increase in transposition activity and copy number among moso bamboo wild type and Arabidopsis transgenic plants under heat stress. Comparison of promoter activity in transgenic plants indicated that 5’LTR promoter activity was higher than CaMV35s promoter. Additionally, yeast one-hybrid (Y1H) system and in planta biomolecular fluorescence complementation (BiFC) assay revealed interactions of heat-dependent transcription factors (TFs) with 5’LTR sequence and direct interactions of TFs with pol and gag. Conclusions Our results conclude that the 5’LTR acts as a promoter and could regulate the LTR retrotransposons in moso bamboo under heat stress.

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CSN5A Subunit of COP9 Signalosome Temporally Buffers Response to Heat in Arabidopsis

Biomolecules ◽

10.3390/biom9120805 ◽

2019 ◽

Vol 9 (12) ◽

pp. 805

Author(s):

Amit Kumar Singh ◽

Brijesh Singh Yadav ◽

Shanmuhapreya Dhanapal ◽

Mark Berliner ◽

Alin Finkelshtein ◽

...

Keyword(s):

Heat Stress ◽

Environmental Stress ◽

Lateral Roots ◽

Model Organism ◽

Immunoblot Analysis ◽

Auxin Signaling ◽

Plant Responses ◽

Stress Studies ◽

Evolutionarily Conserved

The COP9 (constitutive photomorphogenesis 9) signalosome (CSN) is an evolutionarily conserved protein complex which regulates various growth and developmental processes. However, the role of CSN during environmental stress is largely unknown. Using Arabidopsis as model organism, we used CSN hypomorphic mutants to study the role of the CSN in plant responses to environmental stress and found that heat stress specifically enhanced the growth of csn5a-1 but not the growth of other hypomorphic photomorphogenesis mutants tested. Following heat stress, csn5a-1 exhibits an increase in cell size, ploidy, photosynthetic activity, and number of lateral roots and an upregulation of genes connected to the auxin response. Immunoblot analysis revealed an increase in deneddylation of CUL1 but not CUL3 following heat stress in csn5a-1, implicating improved CUL1 activity as a basis for the improved growth of csn5a-1 following heat stress. Studies using DR5::N7-VENUS and DII-VENUS reporter constructs confirm that the heat-induced growth is due to an increase in auxin signaling. Our results indicate that CSN5A has a specific role in deneddylation of CUL1 and that CSN5A is required for the recovery of AUX/IAA repressor levels following recurrent heat stress to regulate auxin homeostasis in Arabidopsis.

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