scholarly journals Selection for synchronized cell division in simple multicellular organisms

2018 ◽  
Author(s):  
Jason Olejarz ◽  
Kamran Kaveh ◽  
Carl Veller ◽  
Martin A. Nowak
Keyword(s):  
Cell Division ◽  
Natural Selection ◽  
Population Model ◽  
Natural Question ◽  
Cell Divisions ◽  
Major Transition ◽  
History Of ◽  
Selection For ◽  
Life On Earth ◽  
Multicellular Organisms

AbstractThe evolution of multicellularity was a major transition in the history of life on earth. Conditions under which multicellularity is favored have been studied theoretically and experimentally. But since the construction of a multicellular organism requires multiple rounds of cell division, a natural question is whether these cell divisions should be synchronous or not. We study a simple population model in which there compete simple multicellular organisms that grow either by synchronous or asynchronous cell divisions. We demonstrate that natural selection can act differently on synchronous and asynchronous cell division, and we offer intuition for why these phenotypes are generally not neutral variants of each other.

The Major Transitions in Evolution

1997 ◽  
Author(s):  
John Maynard Smith ◽  
Eors Szathmary
Keyword(s):  
Full Range ◽  
Evolution Of Cooperation ◽  
Major Transitions ◽  
Insect Societies ◽  
Wide Range ◽  
Major Transition ◽  
Life Itself ◽  
History Of ◽  
Emergence Of Cooperation ◽  
Multicellular Organisms

Over the history of life there have been several major changes in the way genetic information is organized and transmitted from one generation to the next. These transitions include the origin of life itself, the first eukaryotic cells, reproduction by sexual means, the appearance of multicellular plants and animals, the emergence of cooperation and of animal societies, and the unique language ability of humans. This ambitious book provides the first unified discussion of the full range of these transitions. The authors highlight the similarities between different transitions--between the union of replicating molecules to form chromosomes and of cells to form multicellular organisms, for example--and show how understanding one transition sheds light on others. They trace a common theme throughout the history of evolution: after a major transition some entities lose the ability to replicate independently, becoming able to reproduce only as part of a larger whole. The authors investigate this pattern and why selection between entities at a lower level does not disrupt selection at more complex levels. Their explanation encompasses a compelling theory of the evolution of cooperation at all levels of complexity. Engagingly written and filled with numerous illustrations, this book can be read with enjoyment by anyone with an undergraduate training in biology. It is ideal for advanced discussion groups on evolution and includes accessible discussions of a wide range of topics, from molecular biology and linguistics to insect societies.

scholarly journals Selection for synchronized cell division in simple multicellular organisms

2018 ◽  
Vol 457 ◽  
pp. 170-179 ◽  
Author(s):  
Jason Olejarz ◽  
Kamran Kaveh ◽  
Carl Veller ◽  
Martin A. Nowak
Keyword(s):  
Cell Division ◽  
Selection For ◽  
Multicellular Organisms

scholarly journals Transformation of Riccia fluitans, an Amphibious Liverwort Dynamically Responding to Environmental Changes

2020 ◽  
Vol 21 (15) ◽  
pp. 5410
Author(s):  
Felix Althoff ◽  
Sabine Zachgo
Keyword(s):  
Molecular Mechanisms ◽  
Environmental Changes ◽  
Morphological Plasticity ◽  
Terrestrial Ecosystems ◽  
Transformation Protocol ◽  
Major Transition ◽  
Terrestrial Environments ◽  
History Of ◽  
Life On Earth ◽  
Colonization Of Land

The colonization of land by streptophyte algae, ancestors of embryophyte plants, was a fundamental event in the history of life on earth. Bryophytes are early diversifying land plants that mark the transition from freshwater to terrestrial ecosystems. The amphibious liverwort Riccia fluitans can thrive in aquatic and terrestrial environments and thus represents an ideal organism to investigate this major transition. Therefore, we aimed to establish a transformation protocol for R. fluitans to make it amenable for genetic analyses. An Agrobacterium transformation procedure using R. fluitans callus tissue allows to generate stably transformed plants within 10 weeks. Furthermore, for comprehensive studies spanning all life stages, we demonstrate that the switch from vegetative to reproductive development can be induced by both flooding and poor nutrient availability. Interestingly, a single R. fluitans plant can consecutively adapt to different growth environments and forms distinctive and reversible features of the thallus, photosynthetically active tissue that is thus functionally similar to leaves of vascular plants. The morphological plasticity affecting vegetative growth, air pore formation, and rhizoid development realized by one genotype in response to two different environments makes R. fluitans ideal to study the adaptive molecular mechanisms enabling the colonialization of land by aquatic plants.

Severe telomere shortening in patients with paroxysmal nocturnal hemoglobinuria affects both GPI– and GPI+ hematopoiesis

Blood ◽  
2003 ◽  
Vol 102 (2) ◽  
pp. 514-516 ◽  
Author(s):  
Anastasios Karadimitris ◽  
David J. Araten ◽  
Lucio Luzzatto ◽  
Rosario Notaro
Keyword(s):  
Stem Cells ◽  
Cell Division ◽  
Aplastic Anemia ◽  
Distinctive Feature ◽  
Paroxysmal Nocturnal Hemoglobinuria ◽  
Epigenetic Change ◽  
Telomere Shortening ◽  
Hematopoietic Stem ◽  
Cell Divisions ◽  
History Of

Abstract A most distinctive feature of paroxysmal nocturnal hemoglobinuria (PNH) is that in each patient glycosylphosphatidylinositol-negative (GPI–) and GPI+ hematopoietic stem cells (HSCs) coexist, and both contribute to hematopoiesis. Telomere size correlates inversely with the cell division history of HSCs. In 10 patients with hemolytic PNH the telomeres in sorted GPI– granulocytes were shorter than in sorted GPI+ granulocytes in 4 cases, comparable in 2 cases, and longer in the remaining 4 cases. Furthermore, the telomeres of both GPI– and GPI+ hematopoietic cells were markedly shortened compared with age-matched controls. The short telomeres in the GPI– cells probably reflect the large number of cell divisions required for the progeny of a single cell to contribute a large proportion of hematopoiesis. The short telomeres of the GPI+ cells indicate that the residual hematopoiesis contributed by these cells is not normal. This epigenetic change is an additional feature shared by PNH and aplastic anemia.

scholarly journals Natural reward drives the advancement of life

2020 ◽  
Vol 5 ◽  
pp. 1-35
Author(s):  
Owen M. Gilbert
Keyword(s):  
Free Energy ◽  
Natural Selection ◽  
Resource Limitation ◽  
Economic Systems ◽  
Natural Reward ◽  
Resource Limited ◽  
Evolutionary Force ◽  
History Of ◽  
Sudden Appearance ◽  
Life On Earth

Throughout the history of life on earth, rare and complex innovations have periodically increased the efficiency with which abiotic free energy and biotic resources are converted to biomass and organismal diversity. Such macroevolutionary expansions have increased the total amount of abiotic free energy utilized by life and shaped the earth’s ecosystems. Meanwhile, Darwin’s theory of natural selection assumes a historical, worldwide state of effective resource limitation, which could not possibly be true if life evolved from one or a few original ancestors. In this paper, I analyze the self-contradiction in Darwin’s theory that comes from viewing the world and universe as effectively resource limited. I then extend evolutionary theory to include a second deterministic evolutionary force, natural reward. Natural reward operates on complex inventions produced by natural selection and is analogous to the reward for innovation in human economic systems. I hypothesize that natural reward, when combined with climate change and extinction, leads to the increased innovativeness, or what I call the advancement, of life with time. I then discuss applications of the theory of natural reward to the evolution of evolvability, the apparent sudden appearance of new forms in the fossil record, and human economic evolution. I conclude that the theory of natural reward holds promise as an explanation for the historical advancement of life on earth.

Probing the Mitotic History and Developmental Stage of Hematopoietic Cells Using Single Telomere Length Analysis (STELA)

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 2449-2449
Author(s):  
Mark Hills ◽  
Kai Lucke ◽  
Connie J. Eaves ◽  
Peter M. Lansdorp
Keyword(s):  
Stem Cells ◽  
Cell Division ◽  
Cord Blood ◽  
Telomere Length ◽  
Progenitor Cells ◽  
Hematopoietic Cells ◽  
Cell Divisions ◽  
Stem And Progenitor Cells ◽  
History Of ◽  
Length Analysis

Abstract In most somatic cells, telomeres shorten with each round of cell division. As a result telomere length can be used to assess the mitotic history of cells with some important caveats: the telomere length at birth is highly variable (presumably reflecting different alleles of genes regulating telomere length in the germline), telomere losses can be compensated by telomerase and the overall decline in telomere length includes sporadic, variable losses of telomere repeats resulting from damage to telomeric DNA and/or replication errors. The first caveat can be circumvented by testing cells from the same individual and sporadic telomere losses can be analyzed by single telomere length analysis (STELA). It is more difficult to exclude the effect of telomerase on telomere length but we have previously shown that, despite readily detectable expression of telomerase, hematopoietic stem and progenitor cells show a progressive decline in telomere length with cell division and with age. The clinical relevance of telomere shortening is illustrated in several recent studies linking very short telomeres to bone marrow failure and pulmonary fibrosis. We now show that purified human hematopoietic populations from mobilized peripheral blood (MPB) and cord blood (CB) enriched for stem cells (Lin−CD34+CD38−Rho−) and successively more mature cells display progressively shorter telomeres, pointing to the utility of this method for studies of the mitotic relationship between various stem and progenitor cells. Ultra-short telomeres were readily observed (and found to be significantly more frequent) in terminally differentiated cell populations of MPB, suggesting that sporadic telomere losses occur more frequently during differentiation. When 1000 Lin−CD34+CD38−Rho− cord blood cells were transplanted into two immuno-deficient mice, the most primitive human hematopoietic cells with a CD34+CD38− phenotype lost 3970 and 2790 bp respectively following regeneration in vivo, indicative of ~ 30–80 cell divisions assuming a telomere loss of 50–100 bp/division. Further losses in more differentiated cells were similar to those observed in cells before transplantation. These results illustrate the power of STELA for analysis of telomeres in rare cells and point to a novel strategy to study the turnover and replicative history of cells. Furthermore, these data demonstrate that self-renewal divisions in stem cells rather than additional cell divisions in downstream progenitors are the primary cause of telomere loss following transplantation.

Stimulated Virus Production in Vinblastine and Cytochalasin-Induced Multinucleate Cells

1970 ◽  
Vol 28 ◽  
pp. 186-187
Author(s):  
Krishan Awtar
Keyword(s):  
Cell Division ◽  
Normal Cell ◽  
Virus Production ◽  
Multinucleate Cells ◽  
Daughter Cells ◽  
Cell Divisions ◽  
Nuclear Membranes ◽  
Division 2 ◽  
Vinblastine Sulfate

Exposure of cells to low sublethal but mitosis-arresting doses of vinblastine sulfate (Velban) results in the initial arrest of cells in mitosis followed by their subsequent return to an “interphase“-like stage. A large number of these cells reform their nuclear membranes and form large multimicronucleated cells, some containing as many as 25 or more micronuclei (1). Formation of large multinucleate cells is also caused by cytochalasin, by causing the fusion of daughter cells at the end of an otherwise .normal cell division (2). By the repetition of this process through subsequent cell divisions, large cells with 6 or more nuclei are formed.

Conclusion

2017 ◽  
Author(s):  
Erin Lambert
Keyword(s):  
Dutch Reformed ◽  
Christian Life ◽  
The Reformation ◽  
History Of ◽  
Life On Earth

This conclusion offers a brief commentary on the implications of song, resurrection, and belief for the broader history of the Reformation. It relates the various uses of song by Lutherans (hymn pamphlets), Anabaptists (martyr songs), Dutch Reformed exiles (psalms), and Catholics (motets) to these confessions’ ideas of belief as it concerned resurrection and their understandings of how belief was bound up with the Christian life on earth. In place of a story of the transformation of one conception of Christianity to many different conceptions, this book as a whole suggests that the Reformation might be reconceived as a much more elemental debate about the role that belief was to play in a Christian life.

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