The Experts below are selected from a list of 42 Experts worldwide ranked by ideXlab platform
Frantisek Baluska - One of the best experts on this subject based on the ideXlab platform.
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Cell-Cell Channels, Viruses, and Evolution
Annals of the New York Academy of Sciences, 2020Co-Authors: Frantisek BaluskaAbstract:Between prokaryotic cells and eukaryotic cells there is dramatic difference in complexity which represents a problem for the current version of the cell Theory, as well as for the current version of evolution Theory. In the past few decades, the Serial Endosymbiotic Theory of Lynn Margulis has been confirmed. This results in a radical departure from our understanding of living systems: the eukaryotic cell represents de facto "cells-within-cell." Higher order "cells-within-cell" situations are obvious at the eukaryotic cell level in the form of secondary and tertiary endosymbiosis, or in the male and female gametophytes of higher plants. The next challenge of the current version of the cell Theory is represented by the fact that the multicellular fungi and plants are, in fact, supracellular assemblies as their cells are not physically separated from each other. Moreover, there are also examples of alliances and mergings between multicellular organisms. Infection, especially the viral one, but also bacterial and fungal infections, followed by symbiosis, is proposed to act as the major force that drives the biological evolution toward higher complexity.
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Cell‐Cell Channels, Viruses, and Evolution
Annals of the New York Academy of Sciences, 2009Co-Authors: Frantisek BaluskaAbstract:: Between prokaryotic cells and eukaryotic cells there is dramatic difference in complexity which represents a problem for the current version of the cell Theory, as well as for the current version of evolution Theory. In the past few decades, the Serial Endosymbiotic Theory of Lynn Margulis has been confirmed. This results in a radical departure from our understanding of living systems: the eukaryotic cell represents de facto"cells-within-cell." Higher order "cells-within-cell" situations are obvious at the eukaryotic cell level in the form of secondary and tertiary endosymbiosis, or in the male and female gametophytes of higher plants. The next challenge of the current version of the cell Theory is represented by the fact that the multicellular fungi and plants are, in fact, supracellular assemblies as their cells are not physically separated from each other. Moreover, there are also examples of alliances and mergings between multicellular organisms. Infection, especially the viral one, but also bacterial and fungal infections, followed by symbiosis, is proposed to act as the major force that drives the biological evolution toward higher complexity.
G. Hinkle - One of the best experts on this subject based on the ideXlab platform.
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Symbiosis and the origin of eukaryotic motility
1991Co-Authors: L. Margulis, G. HinkleAbstract:Ongoing work to test the hypothesis of the origin of eukaryotic cell organelles by microbial symbioses is discussed. Because of the widespread acceptance of the Serial Endosymbiotic Theory (SET) of the origin of plastids and mitochondria, the idea of the symbiotic origin of the centrioles and axonemes for spirochete bacteria motility symbiosis was tested. Intracellular microtubular systems are purported to derive from symbiotic associations between ancestral eukaryotic cells and motile bacteria. Four lines of approach to this problem are being pursued: (1) cloning the gene of a tubulin-like protein discovered in Spirocheata bajacaliforniesis; (2) seeking axoneme proteins in spirochets by antibody cross-reaction; (3) attempting to cultivate larger, free-living spirochetes; and (4) studying in detail spirochetes (e.g., Cristispira) symbiotic with marine animals. Other aspects of the investigation are presented.
Lynn Margulis - One of the best experts on this subject based on the ideXlab platform.
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Search for eukaryotic motility proteins in spirochetes: immunological detection of a tektin-like protein in Spirochaeta halophila.
BioSystems, 2003Co-Authors: Alison L. Barth, Jenny A. Stricker, Lynn MargulisAbstract:Abstract The Serial Endosymbiotic Theory (SET) for the spirochete origin of undulipodia (cilia and eukaryotic flagella) predicts that a greater number of axonemal proteins will show homology to spirochete than to other bacterial proteins. To continue testing, the SET proteins associated with eukaryotic motility (tektin, centrin and calmodulin) were sought in Spirochaeta halophila. Western blot immunological detection techniques (for tektin and centrin) and two-dimensional gel analysis (for calmodulin) were used. Tektins are filamentous proteins extending the length of the axoneme in sperm tails and other undulipodia. Whole cell extracts of S. halophila were probed with antibodies made against three sea urchin (Lytechinus pictus) sperm axonemal tektins (tektins A, B, and C). In the spirochetes, one tektin-like protein was detected as a band on Western blots (a C tektin.) An antibody made against Lytechinus pictus sperm tail axonemes, affinity-purified against the C tektin of another sea urchin, Stronglyocentrotus purpuratus, bound to a 30 kDa protein from Spirochaeta halophila. The C tektin epitope was not detected in Escherichia coli. Both the poly- and monoclonal anti-centrin antibodies cross-reacted with multiple proteins in the control alga (Tetraselmis striata) and in the putatively negative control bacterium E. coli. No cross reaction was seen between any anti-centrin antibody and S. halophila. Neither did a two-dimensional gel analysis reveal the presence of calmodulin in these spirochetes or in the two other prokaryotes tested (Spiroplasma citri, Ackoleplasma laidlawii). Although neither centrin nor calmodulin were detected, a 30 kDa tektin-like protein apparently is present in these spirochetes.
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Cell symbioisis Theory: Status and implications for the fossil record
Advances in Space Research, 2002Co-Authors: Lynn Margulis, John F. StolzAbstract:Although the entire Serial Endosymbiotic Theory has not been proven much progress has been made and the nature of the remaining critical observations can be now identified. There is little doubt that, regardless of the precise details, prokaryotes are single genomic systems and all eukaryotic cells are multigenomic ones. Eukaryotic cells are therefore best thought of as co-evolved microbial communities, entities that emerged as the symbiotic partnerships became tightly integrated by the late Late Proterozoic Aeon.
Günther Witzany - One of the best experts on this subject based on the ideXlab platform.
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Serial Endosymbiotic Theory (Set): The Biosemiotic Update
Acta Biotheoretica, 2006Co-Authors: Günther WitzanyAbstract:The Serial Endosymbiotic Theory explains the origin of nucleated eukaryotic cells by a merging of archaebacterial and eubacterial cells. The paradigmatic change is that the driving force behind evolution is not ramification but merging. Lynn Margulis describes the symbiogenetic processes in the language of mechanistic biology in such terms as “merging”, “fusion”, and “incorporation”. Biosemiotics argues that all cell-cell interactions are (rule-governed) sign-mediated interactions, i.e., communication processes. As the description of plant communication demonstrates, the biosemiotic approach is not limited to the level of molecular biology, but is also helpful in examining all sign-mediated interactions between organisms on the phenotypic level. If biosemiotics also uses the notions of “language” and “communication” to describe non-human sign-mediated interactions, then the underlying scientific justification of such usage should be critically considered. Therefore, I summarize the history of this discussion held between 1920 and 1980 and present its result, the pragmatic turn.
L. Margulis - One of the best experts on this subject based on the ideXlab platform.
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Symbiosis and the origin of eukaryotic motility
1991Co-Authors: L. Margulis, G. HinkleAbstract:Ongoing work to test the hypothesis of the origin of eukaryotic cell organelles by microbial symbioses is discussed. Because of the widespread acceptance of the Serial Endosymbiotic Theory (SET) of the origin of plastids and mitochondria, the idea of the symbiotic origin of the centrioles and axonemes for spirochete bacteria motility symbiosis was tested. Intracellular microtubular systems are purported to derive from symbiotic associations between ancestral eukaryotic cells and motile bacteria. Four lines of approach to this problem are being pursued: (1) cloning the gene of a tubulin-like protein discovered in Spirocheata bajacaliforniesis; (2) seeking axoneme proteins in spirochets by antibody cross-reaction; (3) attempting to cultivate larger, free-living spirochetes; and (4) studying in detail spirochetes (e.g., Cristispira) symbiotic with marine animals. Other aspects of the investigation are presented.
