scholarly journals The Nereid on the rise: Platynereis as a model system

EvoDevo ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
B. Duygu Özpolat ◽  
Nadine Randel ◽  
Elizabeth A. Williams ◽  
Luis Alberto Bezares-Calderón ◽  
Gabriele Andreatta ◽  
...  
Keyword(s):  
Single Cell ◽  
General Characteristic ◽  
Whole Body ◽  
Sensory Cells ◽  
Body Volume ◽  
Reproduction Biology ◽  
Genomics Research ◽  
Platynereis Dumerilii ◽  
Young Worm ◽  
Volume Electron Microscopy

AbstractThe Nereid Platynereis dumerilii (Audouin and Milne Edwards (Annales des Sciences Naturelles 1:195–269, 1833) is a marine annelid that belongs to the Nereididae, a family of errant polychaete worms. The Nereid shows a pelago-benthic life cycle: as a general characteristic for the superphylum of Lophotrochozoa/Spiralia, it has spirally cleaving embryos developing into swimming trochophore larvae. The larvae then metamorphose into benthic worms living in self-spun tubes on macroalgae. Platynereis is used as a model for genetics, regeneration, reproduction biology, development, evolution, chronobiology, neurobiology, ecology, ecotoxicology, and most recently also for connectomics and single-cell genomics. Research on the Nereid started with studies on eye development and spiralian embryogenesis in the nineteenth and early twentieth centuries. Transitioning into the molecular era, Platynereis research focused on posterior growth and regeneration, neuroendocrinology, circadian and lunar cycles, fertilization, and oocyte maturation. Other work covered segmentation, photoreceptors and other sensory cells, nephridia, and population dynamics. Most recently, the unique advantages of the Nereid young worm for whole-body volume electron microscopy and single-cell sequencing became apparent, enabling the tracing of all neurons in its rope-ladder-like central nervous system, and the construction of multimodal cellular atlases. Here, we provide an overview of current topics and methodologies for P. dumerilii, with the aim of stimulating further interest into our unique model and expanding the active and vibrant Platynereis community.

scholarly journals Ciliomotor circuitry underlying whole-body coordination of ciliary activity in the Platynereis larva

2017 ◽  
Author(s):  
Csaba Verasztó ◽  
Nobuo Ueda ◽  
Luis A. Bezares-Calderón ◽  
Aurora Panzera ◽  
Elizabeth A. Williams ◽  
...  
Keyword(s):  
Beat Frequency ◽  
Ciliary Beat Frequency ◽  
Whole Body ◽  
Ciliary Activity ◽  
Ciliary Beating ◽  
Stop And Go ◽  
Multiciliated Cells ◽  
Platynereis Dumerilii ◽  
Catecholaminergic Cells ◽  
Ciliary Locomotion

AbstractCiliated surfaces harbouring synchronously beating cilia can generate fluid flow or drive locomotion. In ciliary swimmers, ciliary beating, arrests, and changes in beat frequency are often coordinated across extended or discontinuous surfaces. To understand how such coordination is achieved, we studied the ciliated larvae of Platynereis dumerilii, a marine annelid. Platynereis larvae have segmental multiciliated cells that regularly display spontaneous coordinated ciliary arrests. We used whole-body connectomics, activity imaging, transgenesis, and neuron ablation to characterize the ciliomotor circuitry. We identified cholinergic, serotonergic, and catecholaminergic ciliomotor neurons. The synchronous rhythmic activation of cholinergic cells drives the coordinated arrests of all cilia. The serotonergic cells are active when cilia are beating. Serotonin inhibits the cholinergic rhythm, and increases ciliary beat frequency. Based on their connectivity and alternating activity, the catecholaminergic cells may generate the rhythm. The ciliomotor circuitry thus constitutes a stop-and-go pacemaker system for the whole-body coordination of ciliary locomotion.

Abstract 15080: Chronic Mild Sleep Curtailment Increases Markers of Adiposity While Maintained Healthy Sleep Reduces These Measures in Women

Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Faris M Zuraikat ◽  
Samantha E Scaccia ◽  
Arindam RoyChoudhury ◽  
Marie-Pierre St-Onge
Keyword(s):  
Skeletal Muscle ◽  
Body Weight ◽  
Sleep Duration ◽  
Cardiovascular Health ◽  
Sleep Time ◽  
Whole Body ◽  
Body Volume ◽  
Insufficient Sleep ◽  
Wrist Actigraphy ◽  
Sleep Condition

Introduction: Over one-third of US adults do not achieve adequate sleep duration of 7 or more h per night. Short sleep is linked to higher odds of cardiometabolic diseases, including obesity. However, whether prolonged insufficient sleep causes increased body weight or adiposity remains unclear. Objective: To compare, in women, changes in body weight and composition in response to prolonged mild sleep restriction (SR) vs maintenance of healthy, habitual sleep (HS). Methods: Women (n=55; age: 35±13 y; BMI: 25.5±3.5 kg/m 2 ) with average adequate sleep duration (total sleep time [TST]=455±23 min) took part in a randomized crossover study with two 6-wk phases: HS and SR. In HS, usual bed and wake times (determined from 2 wk wrist actigraphy and sleep logs) were maintained. In SR, TST was reduced by 1.5 h/night. Sleep was measured continuously and verified weekly for compliance. Body weight and composition were measured at 0 and 6 wk using magnetic resonance imaging (MRI). Linear-mixed models tested interactions of sleep condition with week on outcome measures. Results: Average TST was reduced in SR and unchanged in HS (-87±19 vs -7±26 min, P<0.01). Significant study condition by week interactions were observed for whole-body volume (WBV), waist circumference (WC), and skeletal muscle. In HS, WBV and WC decreased while these measures increased in SR (WBV: -0.47±0.22 vs 0.27±0.05 L, P=0.02; WC: -1.04 ± 0.78 vs 1.16 ± 0.54 cm, P=0.04). Results were similar for skeletal muscle (-0.19 ± 0.07 vs 0.17 ± 0.01 L, P<0.01). A trend for a reduction in weight was observed in HS relative to SR (-0.39±0.31 vs 0.34±0.09 kg, P=0.09). Conclusions: This is the first evidence that prolonged insufficient sleep leads to increased body size in women. Conversely, maintaining adequate sleep may improve body composition. Our data suggest that healthy sleep duration should be a key component of strategies to improve cardiovascular health in women.

scholarly journals Synchrotron imaging of the grasshopper tracheal system: morphological and physiological components of tracheal hypermetry

2009 ◽  
Vol 297 (5) ◽  
pp. R1343-R1350 ◽  
Author(s):  
Kendra J. Greenlee ◽  
Joanna R. Henry ◽  
Scott D. Kirkton ◽  
Mark W. Westneat ◽  
Kamel Fezzaa ◽  
...  
Keyword(s):  
Late Stage ◽  
Early Stage ◽  
Tissue Growth ◽  
Whole Body ◽  
Body Volume ◽  
Volume Changes ◽  
Tracheal System ◽  
Body Regions ◽  
Air Sacs ◽  
Synchrotron Imaging

As grasshoppers increase in size during ontogeny, they have mass specifically greater whole body tracheal and tidal volumes and ventilation than predicted by an isometric relationship with body mass and body volume. However, the morphological and physiological bases to this respiratory hypermetry are unknown. In this study, we use synchrotron imaging to demonstrate that tracheal hypermetry in developing grasshoppers ( Schistocerca americana) is due to increases in air sacs and tracheae and occurs in all three body segments, providing evidence against the hypothesis that hypermetry is due to gaining flight ability. We also assessed the scaling of air sac structure and function by assessing volume changes of focal abdominal air sacs. Ventilatory frequencies increased in larger animals during hypoxia (5% O2) but did not scale in normoxia. For grasshoppers in normoxia, inflated and deflated air sac volumes and ventilation scaled hypermetrically. During hypoxia (5% O2), many grasshoppers compressed air sacs nearly completely regardless of body size, and air sac volumes scaled isometrically. Together, these results demonstrate that whole body tracheal hypermetry and enhanced ventilation in larger/older grasshoppers are primarily due to proportionally larger air sacs and higher ventilation frequencies in larger animals during hypoxia. Prior studies showed reduced whole body tracheal volumes and tidal volume in late-stage grasshoppers, suggesting that tissue growth compresses air sacs. In contrast, we found that inflated volumes, percent volume changes, and ventilation were identical in abdominal air sacs of late-stage fifth instar and early-stage animals, suggesting that decreasing volume of the tracheal system later in the instar occurs in other body regions that have harder exoskeleton.

Total Body Volume estimates from DXA whole body scans

2011 ◽  
Vol 14 (2) ◽  
pp. 168
Author(s):  
Joseph Wilson ◽  
Jennifer Sherman ◽  
John Shepherd
Keyword(s):  
Whole Body ◽  
Body Volume ◽  
Total Body ◽  
Total Body Volume ◽  
Volume Estimates

scholarly journals Ciliomotor circuitry underlying whole-body coordination of ciliary activity in the Platynereis larva

eLife ◽  
2017 ◽  
Vol 6 ◽  
Author(s):  
Csaba Verasztó ◽  
Nobuo Ueda ◽  
Luis A Bezares-Calderón ◽  
Aurora Panzera ◽  
Elizabeth A Williams ◽  
...  
Keyword(s):  
Beat Frequency ◽  
Ciliary Beat Frequency ◽  
Whole Body ◽  
Ciliary Activity ◽  
Ciliary Beating ◽  
Stop And Go ◽  
Multiciliated Cells ◽  
Platynereis Dumerilii ◽  
Catecholaminergic Cells ◽  
Ciliary Locomotion

Ciliated surfaces harbouring synchronously beating cilia can generate fluid flow or drive locomotion. In ciliary swimmers, ciliary beating, arrests, and changes in beat frequency are often coordinated across extended or discontinuous surfaces. To understand how such coordination is achieved, we studied the ciliated larvae of Platynereis dumerilii, a marine annelid. Platynereis larvae have segmental multiciliated cells that regularly display spontaneous coordinated ciliary arrests. We used whole-body connectomics, activity imaging, transgenesis, and neuron ablation to characterize the ciliomotor circuitry. We identified cholinergic, serotonergic, and catecholaminergic ciliomotor neurons. The synchronous rhythmic activation of cholinergic cells drives the coordinated arrests of all cilia. The serotonergic cells are active when cilia are beating. Serotonin inhibits the cholinergic rhythm, and increases ciliary beat frequency. Based on their connectivity and alternating activity, the catecholaminergic cells may generate the rhythm. The ciliomotor circuitry thus constitutes a stop-and-go pacemaker system for the whole-body coordination of ciliary locomotion.

scholarly journals Dynamic Imaging of Marrow-Resident Granulocytes Interacting with Human Mesenchymal Stem Cells upon Systemic Lipopolysaccharide Challenge

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Jay T. Myers ◽  
Deborah S. Barkauskas ◽  
Alex Y. Huang
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Single Cell ◽  
Human Mesenchymal Stem Cells ◽  
Dynamic Imaging ◽  
Whole Body ◽  
Whole Body Imaging ◽  
Single Cell Level ◽  
Cell Level

Human mesenchymal stem cells (hMSCs) have gained intense research interest due to their immune-modulatory, tissue differentiating, and homing properties to sites of inflammation. Despite evidence demonstrating the biodistribution of infused hMSCs in target organs using static fluorescence imaging or whole-body imaging techniques, surprisingly little is known about how hMSCs behave dynamically within host tissues on a single-cell levelin vivo. Here, we infused fluorescently labeled clinical-grade hMSCs into immune-competent mice in which neutrophils and monocytes express a second fluorescent marker under the lysozyme M (LysM) promoter. Using intravital two-photon microscopy (TPM), we were able for the first time to capture dynamic interactions between hMSCs and LysM+granulocytes in the calvarium bone marrow of recipient mice during systemic LPS challenge in real time. Interestingly, many of the infused hMSCs remained intact despite repeated cellular contacts with host neutrophils. However, we were able to observe the destruction and subsequent phagocytosis of some hMSCs by surrounding granulocytes. Thus, our imaging platform provides opportunities to gain insight into the biology and therapeutic mechanisms of hMSCsin vivoat a single-cell level within live hosts.

scholarly journals Spatiotemporal dynamics of inner ear sensory and non-sensory cells revealed by single-cell transcriptomics

Cell Reports ◽  
2021 ◽  
Vol 36 (2) ◽  
pp. 109358
Author(s):  
Taha A. Jan ◽  
Yasmin Eltawil ◽  
Angela H. Ling ◽  
Leon Chen ◽  
Daniel C. Ellwanger ◽  
...  
Keyword(s):  
Single Cell ◽  
Inner Ear ◽  
Spatiotemporal Dynamics ◽  
Sensory Cells

scholarly journals The Impact of Single-Cell Genomics on Adipose Tissue Research

2020 ◽  
Vol 21 (13) ◽  
pp. 4773
Author(s):  
Alana Deutsch ◽  
Daorong Feng ◽  
Jeffrey E. Pessin ◽  
Kosaku Shinoda
Keyword(s):  
Adipose Tissue ◽  
Single Cell ◽  
Energy Homeostasis ◽  
Whole Body ◽  
Diabetes Research ◽  
Obesity And Diabetes ◽  
Important Regulator ◽  
Whole Body Metabolism ◽  
Tissue Aging ◽  
The Impact

Adipose tissue is an important regulator of whole-body metabolism and energy homeostasis. The unprecedented growth of obesity and metabolic disease worldwide has required paralleled advancements in research on this dynamic endocrine organ system. Single-cell RNA sequencing (scRNA-seq), a highly meticulous methodology used to dissect tissue heterogeneity through the transcriptional characterization of individual cells, is responsible for facilitating critical advancements in this area. The unique investigative capabilities achieved by the combination of nanotechnology, molecular biology, and informatics are expanding our understanding of adipose tissue’s composition and compartmentalized functional specialization, which underlie physiologic and pathogenic states, including adaptive thermogenesis, adipose tissue aging, and obesity. In this review, we will summarize the use of scRNA-seq and single-nuclei RNA-seq (snRNA-seq) in adipocyte biology and their applications to obesity and diabetes research in the hopes of increasing awareness of the capabilities of this technology and acting as a catalyst for its expanded use in further investigation.

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