scholarly journals Coccolith arrangement follows Eulerian mathematics in the coccolithophore Emiliania huxleyi

2017 ◽  
Author(s):  
Kai Xu ◽  
David Hutchins ◽  
Kunshan Gao
Keyword(s):  
Cell Division ◽  
Natural Selection ◽  
Cell Growth ◽  
Cell Surface ◽  
Surface Area ◽  
Emiliania Huxleyi ◽  
Simulation Software ◽  
Ecological Role ◽  
Carbon Biogeochemistry ◽  
Oceanic Carbon

Background. The globally abundant coccolithophore, Emiliania huxleyi, plays an important ecological role in oceanic carbon biogeochemistry by forming a cellular covering of plate-like CaCO3 crystals (coccoliths) and fixing CO2. It is unknown how the cells arrange different sizes of coccoliths to maintain full coverage as the cell surface area changes due to growth and cell division. Methods. We used Euler’s polyhedron formula and simulation software CaGe, validated with the geometries of coccoliths, to analyses the coccolith topology of coccosphere and the arrange mechanism. Results. The cells arrange each of the coccoliths to interlock with 4–6 others to keep pace with cell growth and cell division. Conclusions. This study represents an example of how natural selection has arrived at a solution based on Euler’s polyhedral formula in response to the challenge of maintaining a CaCO3 covering on coccolithophore cells as cell size changes.

scholarly journals Coccolith arrangement follows Eulerianmathematics in the coccolithophore Emiliania huxleyi

2018 ◽  
Author(s):  
Kai Xu ◽  
David Hutchins ◽  
Kunshan Gao
Keyword(s):  
Cell Division ◽  
Cell Surface ◽  
Surface Area ◽  
Emiliania Huxleyi ◽  
Daily Cycle ◽  
Cell Surface Area ◽  
Carbon Biogeochemistry ◽  
Variable Light ◽  
Cell Changes ◽  
Oceanic Carbon

Background. The globally abundant coccolithophore, Emiliania huxleyi, plays an importantecological role in oceanic carbon biogeochemistry by forming a cellularcovering of plate-like CaCO 3 crystals (coccoliths) and fixing CO 2 .It is unknown how the cells arrange different-size of coccoliths to maintainfull coverage, as the cell surface area of the cell changes during daily cycle. Methods. We used Euler’s polyhedron formula and CaGe simulationsoftware, validated with the geometries of coccoliths, to analze and simulatethe coccolith topology of the coccosphere and to explore the arrangementmechanisms. Results. There were only small variations in the geometries ofcoccoliths, even when the cells were cultured under variable light conditions.Because of geometric limits, small coccoliths tended to interlock with fewerand larger coccoliths, and vice versa. Consequently, to sustain a full coverageon the surface of cell, each coccolith was arranged to interlock with four tosix others, which in turn led to each coccosphere contains at least 6coccoliths. Conclusions. The number of coccoliths per coccosphere must keep pacewith changes on the cell surface area as a result of photosynthesis,respiration and cell division. This study is an example of natural selectionfollowing Euler’s polyhedral formula, in response to the challenge ofmaintaining a CaCO 3 covering on coccolithophore cells as cell sizechanges.

scholarly journals Coccolith arrangement follows Eulerianmathematics in the coccolithophore Emiliania huxleyi

2018 ◽  
Author(s):  
Kai Xu ◽  
David Hutchins ◽  
Kunshan Gao
Keyword(s):  
Cell Division ◽  
Cell Surface ◽  
Surface Area ◽  
Emiliania Huxleyi ◽  
Daily Cycle ◽  
Cell Surface Area ◽  
Carbon Biogeochemistry ◽  
Variable Light ◽  
Cell Changes ◽  
Oceanic Carbon

Background. The globally abundant coccolithophore, Emiliania huxleyi, plays an importantecological role in oceanic carbon biogeochemistry by forming a cellularcovering of plate-like CaCO 3 crystals (coccoliths) and fixing CO 2 .It is unknown how the cells arrange different-size of coccoliths to maintainfull coverage, as the cell surface area of the cell changes during daily cycle. Methods. We used Euler’s polyhedron formula and CaGe simulationsoftware, validated with the geometries of coccoliths, to analze and simulatethe coccolith topology of the coccosphere and to explore the arrangementmechanisms. Results. There were only small variations in the geometries ofcoccoliths, even when the cells were cultured under variable light conditions.Because of geometric limits, small coccoliths tended to interlock with fewerand larger coccoliths, and vice versa. Consequently, to sustain a full coverageon the surface of cell, each coccolith was arranged to interlock with four tosix others, which in turn led to each coccosphere contains at least 6coccoliths. Conclusions. The number of coccoliths per coccosphere must keep pacewith changes on the cell surface area as a result of photosynthesis,respiration and cell division. This study is an example of natural selectionfollowing Euler’s polyhedral formula, in response to the challenge ofmaintaining a CaCO 3 covering on coccolithophore cells as cell sizechanges.

scholarly journals Coccolith arrangement follows Eulerian mathematics in the coccolithophore Emiliania huxleyi

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e4608 ◽  
Author(s):  
Kai Xu ◽  
David Hutchins ◽  
Kunshan Gao
Keyword(s):  
Cell Surface ◽  
Surface Area ◽  
Emiliania Huxleyi ◽  
Simulation Software ◽  
Cell Surface Area ◽  
Full Coverage ◽  
Carbon Biogeochemistry ◽  
Variable Light ◽  
Cell Changes ◽  
Oceanic Carbon

Background The globally abundant coccolithophore, Emiliania huxleyi, plays an important ecological role in oceanic carbon biogeochemistry by forming a cellular covering of plate-like CaCO3 crystals (coccoliths) and fixing CO2. It is unknown how the cells arrange different-sized coccoliths to maintain full coverage, as the cell surface area of the cell changes during daily cycle. Methods We used Euler’s polyhedron formula and CaGe simulation software, validated with the geometries of coccoliths, to analyze and simulate the coccolith topology of the coccosphere and to explore the arrangement mechanisms. Results There were only small variations in the geometries of coccoliths, even when the cells were cultured under variable light conditions. Because of geometric limits, small coccoliths tended to interlock with fewer and larger coccoliths, and vice versa. Consequently, to sustain a full coverage on the surface of cell, each coccolith was arranged to interlock with four to six others, which in turn led to each coccosphere contains at least six coccoliths. Conclusion The number of coccoliths per coccosphere must keep pace with changes on the cell surface area as a result of photosynthesis, respiration and cell division. This study is an example of natural selection following Euler’s polyhedral formula, in response to the challenge of maintaining a CaCO3 covering on coccolithophore cells as cell size changes.

scholarly journals Cortical regulation of cell size by a sizer cdr2p

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Kally Z Pan ◽  
Timothy E Saunders ◽  
Ignacio Flor-Parra ◽  
Martin Howard ◽  
Fred Chang
Keyword(s):  
Cell Division ◽  
Protein Kinase ◽  
Cell Surface ◽  
Surface Area ◽  
Control Mechanism ◽  
Size Control ◽  
Mitotic Entry ◽  
Medial Cortex ◽  
Peripheral Membrane Protein ◽  
Dose Dependent

Cells can, in principle, control their size by growing to a specified size before commencing cell division. How any cell actually senses its own size remains poorly understood. The fission yeast Schizosaccharomyces pombe are rod-shaped cells that grow to ∼14 µm in length before entering mitosis. In this study, we provide evidence that these cells sense their surface area as part of this size control mechanism. We show that cells enter mitosis at a certain surface area, as opposed to a certain volume or length. A peripheral membrane protein kinase cdr2p has properties of a dose-dependent ‘sizer’ that controls mitotic entry. As cells grow, the local cdr2p concentration in nodes at the medial cortex accumulates as a measure of cell surface area. Our findings, which challenge a previously proposed pom1p gradient model, lead to a new model in which cells sense their size by using cdr2p to probe the surface area over the whole cell and relay this information to the medial cortex.

Spatial distribution of the parasite Kroyeria carchariaeglauci Hesse, 1879 (Copepoda: Siphonostomatoida: Kroyeriidae) on gills of the blue shark (Prionace glauca (L., 1758))

1987 ◽  
Vol 65 (5) ◽  
pp. 1275-1281 ◽  
Author(s):  
George W. Benz ◽  
Kevin S. Dupre
Keyword(s):  
Spatial Distribution ◽  
Natural Selection ◽  
Distribution Pattern ◽  
Surface Area ◽  
Blue Shark ◽  
Prionace Glauca ◽  
Homogeneous Groups ◽  
Secondary Lamellae ◽  
Gill Filaments ◽  
Gill Surface Area

Five blue sharks (Prionace glauca) were examined for gill-infesting copepods. Three species of siphonostomatoid copepods were collected: Gangliopus pyriformis, Phyllothyreus cornutus, and Kroyeria carchariaeglauci. The spatial distribution of K. carchariaeglauci was analyzed. The number of K. carchariaeglauci per shark was positively related to gill surface area and host size. Copepods were unevenly distributed amongst hemibranchs; flanking hemibranchs could be arranged into three statistically homogeneous groups. Female K. carchariaeglauci typically attached themselves within the middle 40% of each hemibranch; males were more evenly dispersed. Eighty percent of all K. carchariaeglauci attached themselves to secondary lamellae, the remainder were in the underlying excurrent water channels. Most K. carchariaeglauci were located between 10 and 25 mm along the lengths of gill filaments. Overall, the spatial distribution of K. carchariaeglauci was quite specific in all study planes. Explanation of this distribution is set forth in terms of natural selection pressures; however, the equally plausible explanation that the distribution pattern exhibited by these copepods is phylogenetically determined and may have little to do with contemporary selective constraints should not be ignored.

Relations between cell growth and cell division

1961 ◽  
Vol 23 (2) ◽  
pp. 354-360 ◽  
Author(s):  
I.L. Cameron ◽  
D.M. Prescott
Keyword(s):  
Cell Division ◽  
Cell Growth

Inhibition of DNA synthesis and cell division by a cell surface sialoglycopeptide

1989 ◽  
Vol 139 (2) ◽  
pp. 269-274 ◽  
Author(s):  
Heideh Fattaey ◽  
Terry C. Johnson ◽  
Hsin-Hwei Chou
Keyword(s):  
Cell Division ◽  
Cell Surface ◽  
Dna Synthesis ◽  
A Cell ◽  
Inhibition Of Dna Synthesis

scholarly journals MiR-26a-5p inhibits GSK3β expression and promotes cardiac hypertrophy in vitro

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e10371
Author(s):  
Liqun Tang ◽  
Jianhong Xie ◽  
Xiaoqin Yu ◽  
Yangyang Zheng
Keyword(s):  
Cell Surface ◽  
Cardiac Hypertrophy ◽  
Surface Area ◽  
Myocardial Cell ◽  
Immunofluorescence Staining ◽  
Cell Surface Area ◽  
Direct Target

Background The role of miR-26a-5p expression in cardiac hypertrophy remains unclear. Herein, the effect of miR-26a-5p on cardiac hypertrophy was investigated using phenylephrine (PE)-induced cardiac hypertrophy in vitro and in a rat model of hypertension-induced hypertrophy in vivo. Methods The PE-induced cardiac hypertrophy models in vitro and vivo were established. To investigate the effect of miR-26a-5p activation on autophagy, the protein expression of autophagosome marker (LC3) and p62 was detected by western blot analysis. To explore the effect of miR-26a-5p activation on cardiac hypertrophy, the relative mRNA expression of cardiac hypertrophy related mark GSK3β was detected by qRT-PCR in vitro and vivo. In addition, immunofluorescence staining was used to detect cardiac hypertrophy related mark α-actinin. The cell surface area was measured by immunofluorescence staining. The direct target relationship between miR-26a-5p and GSK3β was confirmed by dual luciferase report. Results MiR-26a-5p was highly expressed in PE-induced cardiac hypertrophy. MiR-26a-5p promoted LC3II and decreased p62 expression in PE-induced cardiac hypertrophy in the presence or absence of lysosomal inhibitor. Furthermore, miR-26a-5p significantly inhibited GSK3β expression in vitro and in vivo. Dual luciferase report results confirmed that miR-26a-5p could directly target GSK3β. GSK3β overexpression significantly reversed the expression of cardiac hypertrophy-related markers including ANP, ACTA1 and MYH7. Immunofluorescence staining results demonstrated that miR-26a-5p promoted cardiac hypertrophy related protein α-actinin expression, and increased cell surface area in vitro and in vivo. Conclusion Our study revealed that miR-26a-5p promotes myocardial cell autophagy activation and cardiac hypertrophy by regulating GSK3β, which needs further research.

Sign in / Sign up

Export Citation Format

Share Document