A mathematical model for bleb regulation in zebrafish primordial germ cells

2021 ◽  
Author(s):  
Carolin Dirks ◽  
Paul Striewski ◽  
Benedikt Wirth ◽  
Anne Aalto ◽  
Adan Olguin-Olguin
Keyword(s):  
Mathematical Model ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Reaction System ◽  
Surface Model ◽  
Bulk Surface ◽  
Membrane Blebs ◽  
Bleb Formation ◽  
The Mathematical Model

Abstract Blebs are cell protrusions generated by local membrane–cortex detachments followed by expansion of the plasma membrane. Blebs are formed by some migrating cells, e.g. primordial germ cells of the zebrafish. While blebs occur randomly at each part of the membrane in unpolarized cells, a polarization process guarantees the occurrence of blebs at a preferential site and thereby facilitates migration toward a specified direction. Little is known about the factors involved in the controlled and directed bleb generation, yet recent studies revealed the influence of an intracellular flow and the stabilizing role of the membrane–cortex linker molecule Ezrin. Based on this information, we develop and analyse a coupled bulk-surface model describing a potential cellular mechanism by which a bleb could be induced at a controlled site. The model rests upon intracellular Darcy flow and a diffusion–advection–reaction system, describing the temporal evolution from a homogeneous to a strongly anisotropic Ezrin distribution. We prove the well-posedness of the mathematical model and show that simulations qualitatively correspond to experimental observations, suggesting that indeed the interaction of an intracellular flow with membrane proteins can be the cause of the Ezrin redistribution accompanying bleb formation.

scholarly journals The Mathematical Model for Total Pubertal Growth in Idiopathic Growth Hormone (GH) Deficiency Suggests a Moderate Role of GH Dose

2003 ◽  
Vol 88 (10) ◽  
pp. 4748-4753 ◽  
Author(s):  
Michael B. Ranke ◽  
Anders Lindberg ◽  
David D. Martin ◽  
Bert Bakker ◽  
Patrick Wilton ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Growth Hormone ◽  
Gh Deficiency ◽  
Pubertal Growth ◽  
The Mathematical Model

On the role of germ cells in planarian regeneration

Development ◽  
1980 ◽  
Vol 55 (1) ◽  
pp. 53-63
Author(s):  
V. Gremigni ◽  
C. Miceli ◽  
I. Puccinelli
Keyword(s):  
Chromosome Number ◽  
Germ Cells ◽  
Primordial Germ Cells ◽  
Karyological Analysis ◽  
Blastema Formation ◽  
Planarian Regeneration ◽  
Somatic Tissues ◽  
Caudal Area ◽  
Complete Regeneration

Specimens from a polyploid biotype of Dugesia lugubris s.l. were used to clarify the role and fate of germ cells during planarian regeneration. These specimens provide a useful karyological marker because embryonic and somatic cells (3n = 12) can be easily distinguished from male (2n = 8) and female (6n = 24) germ cells by their chromosome number. We succeed in demonstrating how primordial germ cells participate in blastema formation and take part in rebuilding somatic tissues. This evidence was obtained by cutting each planarian specimen twice at appropriate levels. The first aimed to induce primordial germ cells to migrate to the wound. The second cut was performed after complete regeneration and aimed to obtain a blastema from a cephalic or caudal area devoid of gonads. A karyological analysis of mitotic cells present in each blastema obtained after the second cut provided evidence that cells, originally belonging to the germ lines, are still present in somatic tissues even months after complete regeneration. The role of primordial germ cells in planarian regeneration was finally discussed in relation to the phenomenon of metaplasia or transdifferentiation.

Dual role of Ovol2 on the germ cell lineage segregation during gastrulation in mouse embryogenesis

Development ◽  
2022 ◽  
Author(s):  
Yuki Naitou ◽  
Go Nagamatsu ◽  
Nobuhiko Hamazaki ◽  
Kenjiro Shirane ◽  
Masafumi Hayashi ◽  
...  
Keyword(s):  
Germ Cells ◽  
Splice Variant ◽  
Epithelial To Mesenchymal Transition ◽  
Functional Relationship ◽  
Germ Line ◽  
Primordial Germ Cells ◽  
Cell Lineage ◽  
Animal Kingdom ◽  
Mesenchymal Transition

In mammals, primordial germ cells (PGCs), the origin of the germ line, are specified from the epiblast at the posterior region where gastrulation simultaneously occurs, yet the functional relationship between PGC specification and gastrulation remains unclear. Here, we show that Ovol2, a transcription factor conserved across the animal kingdom, balances these major developmental processes by repressing the epithelial-to-mesenchymal transition (EMT) driving gastrulation and the upregulation of genes associated with PGC specification. Ovol2a, a splice variant encoding a repressor domain, directly regulates EMT-related genes and consequently induces re-acquisition of potential pluripotency during PGC specification, whereas Ovol2b, another splice variant missing the repressor domain, directly upregulates genes associated with PGC specification. Taken together, these results elucidate the molecular mechanism underlying allocation of the germ line among epiblast cells differentiating into somatic cells through gastrulation.

Biomechanics of Soft Tissues: The Role of the Mathematical Model on Material Behavior

2019 ◽  
pp. 301-311
Author(s):  
Carlos Bustamante-Orellana ◽  
Robinson Guachi ◽  
Lorena Guachi-Guachi ◽  
Simone Novelli ◽  
Francesca Campana ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Soft Tissues ◽  
Material Behavior ◽  
The Mathematical Model

Functional requirement of gp130-mediated signaling for growth and survival of mouse primordial germ cells in vitro and derivation of embryonic germ (EG) cells

Development ◽  
1996 ◽  
Vol 122 (4) ◽  
pp. 1235-1242 ◽  
Author(s):  
U. Koshimizu ◽  
T. Taga ◽  
M. Watanabe ◽  
M. Saito ◽  
Y. Shirayoshi ◽  
...  
Keyword(s):  
Germ Cells ◽  
Intracellular Signaling ◽  
Primordial Germ Cells ◽  
Cell Formation ◽  
Embryonic Stem ◽  
Oncostatin M ◽  
Receptor Complexes ◽  
Binding Subunit

Leukemia inhibitory factor (LIF) is a cytokine known to influence proliferation and/or survival of mouse primordial germ cells (PGC) in culture. The receptor complex for LIF comprises LIF-binding subunit and non-binding signal transducer, gp130. The gp130 was originally identified as a signal-transducing subunit of interleukin (IL)-6 and later also found to be a functional component of receptor complexes for other LIF-related cytokines (oncostatin M [OSM], ciliary neurotrophic factor [CNTF] and IL-11). In this study, we have analyzed the functional role of gp130-mediated signaling in PGC growth in vitro. OSM was able to fully substitute for LIF; both cytokines promoted the proliferation of migratory PGC (mPGC) and enhanced the viability of postmigratory (colonizing) PGC (cPGC) when cultured on SI/SI4-m220 cells. Interestingly, IL-11 stimulated mPGC growth comparable to LIF and OSM, but did not affect cPGC survival. IL-6 and CNTF did not affect PGC. In addition, a combination of IL-6 and soluble IL-6 binding subunit (sIL-6R), which is known to activate intracellular signaling via gp130, fully reproduced the LIF action of PGC. Both in the presence and absence of LIF, addition of neutralizing antibody against gp130 in culture remarkably blocked cPGC survival. These results suggest a pivotal role of gp130 in PGC development, especially that it is indispensable for cPGC survival as comparable to the c-KIT-mediated action. We have further demonstrated that a combination of LIF with forskolin or retinoic acid, a potent mitogen for PGC, supported the proliferation of PGC, leading to propagation of the embryonic stem cell-like cells, termed embryonic germ (EG) cells. Since EG cells were also obtained by using OSM or the IL-6/sIL-6R complex in place of LIF, a significant contribution of gp130-mediated signaling in EG cell formation was further suggested.

Effects of ten–eleven translocation 1 (Tet1) on DNA methylation and gene expression in chicken primordial germ cells

2019 ◽  
Vol 31 (3) ◽  
pp. 509 ◽  
Author(s):  
Minli Yu ◽  
Dongfeng Li ◽  
Wanyan Cao ◽  
Xiaolu Chen ◽  
Wenxing Du
Keyword(s):  
Gene Expression ◽  
Dna Methylation ◽  
Germ Cells ◽  
Dna Methyltransferase ◽  
Primordial Germ Cells ◽  
Dna Demethylation ◽  
Caveolin 1 ◽  
Expression Of Genes ◽  
Deleted In Azoospermia

Ten–eleven translocation 1 (Tet1) is involved in DNA demethylation in primordial germ cells (PGCs); however, the precise regulatory mechanism remains unclear. In the present study the dynamics of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) in developing PGCs and the role of Tet1 in PGC demethylation were analysed. Results show that 5mC levels dropped significantly after embryonic Day 4 (E4) and 5hmC levels increased reaching a peak at E5–E5.5. Interestingly, TET1 protein was highly expressed during E5 to E5.5, which showed a consistent trend with 5hmC. The expression of pluripotency-associated genes (Nanog, PouV and SRY-box 2 (Sox2)) and germ cell-specific genes (caveolin 1 (Cav1), piwi-like RNA-mediated gene silencing 1 (Piwi1) and deleted in azoospermia-like (Dazl)) was upregulated after E5, whereas the expression of genes from the DNA methyltransferase family was decreased. Moreover, the Dazl gene was highly methylated in early PGCs and then gradually hypomethylated. Knockdown of Tet1 showed impaired survival and proliferation of PGCs, as well as increased 5mC levels and reduced 5hmC levels. Further analysis showed that knockdown of Tet1 led to elevated DNA methylation levels of Dazl and downregulated gene expression including Dazl. Thus, this study reveals the dynamic epigenetic reprogramming of chicken PGCs invivo and the molecular mechanism of Tet1 in regulating genomic DNA demethylation and hypomethylation of Dazl during PGC development.

Role of stem cell factor in somatic–germ cell interactions during prenatal oogenesis

Zygote ◽  
1996 ◽  
Vol 4 (04) ◽  
pp. 349-351 ◽  
Author(s):  
Massimo De Felici ◽  
Anna Di Carlo ◽  
Maurizio Pesce
Keyword(s):  
Stem Cell ◽  
Germ Cells ◽  
Stem Cell Factor ◽  
Molecular Mechanisms ◽  
Primordial Germ Cells ◽  
Significant Progress ◽  
Proliferation And Differentiation ◽  
Complex Events ◽  
Mechanisms Of Migration

During embryogenesis germ cells originate from primordial germ cells (PGCs). The development of mammalian PGCs involves a number of complex events (formation and segregation of PGC precursors, PGC migration and proliferation) which lead to the differentiation of oocytes or prospermatogonia (for a review see De Feliciet al., 1992). During recent years developments in methods for isolation, purification and culture of mouse PGCs have led to significant progress in the understanding of molecular mechanisms of migration, proliferation and differentiation of these cells (for reviews see De Felici, 1994; and De Felici & Pesce, 1994a). In this paper we describe the key role played by stem cell factor (SCF) in PGC development and early folliculogenesis.

scholarly journals Small non-coding RNA profiling and the role of piRNA pathway genes in the protection of chicken primordial germ cells

BMC Genomics ◽  
2014 ◽  
Vol 15 (1) ◽  
pp. 757 ◽  
Author(s):  
Deivendran Rengaraj ◽  
Sang Lee ◽  
Tae Park ◽  
Hong Lee ◽  
Young Kim ◽  
...  
Keyword(s):  
Germ Cells ◽  
Primordial Germ Cells ◽  
Rna Profiling ◽  
Non Coding Rna ◽  
Pirna Pathway

A Control System on Soil Temperature

2014 ◽  
Vol 599-601 ◽  
pp. 673-679
Author(s):  
Shi Guo Chen ◽  
Li Hua Hu ◽  
Dong Sheng Wu ◽  
Xue Yong Chen
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Soil Temperature ◽  
Control Algorithm ◽  
Soil Ecology ◽  
Control Soil ◽  
Pid Algorithm ◽  
And Control ◽  
The Mathematical Model

The soil’s temperature plays an important role of soil ecology research. In order to gain and control soil’ temperature. A control system is proposed for soil’s temperature. And a new control algorithm which is based on the PID algorithm is designed in the control system to handle the complex change of the soil’s temperature. It does not need to know the mathematical model of soil’s temperature. At last, the control result is analyzed in this paper. The result shows that the soil’s temperature is controlled ideal by this control system which is accurate to 0.5°C.

scholarly journals Discovery of the spatial pattern of prickles on the stem of the rose and the mathematical model of the pattern

2019 ◽  
Author(s):  
Kazuaki Amikura ◽  
Hiroshi Ito
Keyword(s):  
Mathematical Model ◽  
Spatial Pattern ◽  
Plant Species ◽  
Statistical Data ◽  
Model Parameters ◽  
Developmental Patterns ◽  
The Mathematical Model ◽  
The Rose

Reproducible pattern is a key characteristic of organisms. Many developmental patterns are known that it is orchestrated by diffusion of the factors. Herein, we reported a novel patterning that seems to be controlled by diffusion factors. Although it looks like the prickles randomly emerge on the stem of rose, we deciphered patterns for the position of prickles with statistical data and proposed a mathematical model to explain the process via which the pattern emerged. By changing the model parameters, we reproduce another pattern on other plant species. This finding indicates that the patterns between many species are organized by similar systems. Moreover, although the pattern of organisms is often linked to its function, we consider the spatial pattern of prickles may have a function to play the role of prickles effectively. Further studies will clarify the role of prickles and reveal the entity of diffusive factors.

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