Journal articles: 'Endosymbiosis'

1

Nowack, Eva C. M., and Michael Melkonian. "Endosymbiotic associations within protists." Philosophical Transactions of the Royal Society B: Biological Sciences 365, no. 1541 (March 12, 2010): 699–712. http://dx.doi.org/10.1098/rstb.2009.0188.

Full text

Abstract:

The establishment of an endosymbiotic relationship typically seems to be driven through complementation of the host's limited metabolic capabilities by the biochemical versatility of the endosymbiont. The most significant examples of endosymbiosis are represented by the endosymbiotic acquisition of plastids and mitochondria, introducing photosynthesis and respiration to eukaryotes. However, there are numerous other endosymbioses that evolved more recently and repeatedly across the tree of life. Recent advances in genome sequencing technology have led to a better understanding of the physiological basis of many endosymbiotic associations. This review focuses on endosymbionts in protists (unicellular eukaryotes). Selected examples illustrate the incorporation of various new biochemical functions, such as photosynthesis, nitrogen fixation and recycling, and methanogenesis, into protist hosts by prokaryotic endosymbionts. Furthermore, photosynthetic eukaryotic endosymbionts display a great diversity of modes of integration into different protist hosts. In conclusion, endosymbiosis seems to represent a general evolutionary strategy of protists to acquire novel biochemical functions and is thus an important source of genetic innovation.

APA, Harvard, Vancouver, ISO, and other styles

2

Takahashi, Toshiyuki. "Method for Stress Assessment of Endosymbiotic Algae in Paramecium bursaria as a Model System for Endosymbiosis." Microorganisms 10, no. 6 (June 18, 2022): 1248. http://dx.doi.org/10.3390/microorganisms10061248.

Full text

Abstract:

Endosymbiosis between heterotrophic host and microalga often breaks down because of environmental conditions, such as temperature change and exposure to toxic substances. By the time of the apparent breakdown of endosymbiosis, it is often too late for the endosymbiotic system to recover. In this study, I developed a technique for the stress assessment of endosymbiotic algae using Paramecium bursaria as an endosymbiosis model, after treatment with the herbicide paraquat, an endosymbiotic collapse inducer. Microcapillary flow cytometry was employed to evaluate a large number of cells in an approach that is more rapid than microscopy evaluation. In the assay, red fluorescence of the chlorophyll reflected the number of endosymbionts within the host cell, while yellow fluorescence fluctuated in response to the deteriorating viability of the endosymbiont under stress. Hence, the yellow/red fluorescence intensity ratio can be used as an algal stress index independent of the algal number. An optical evaluation revealed that the viability of the endosymbiotic algae within the host cell decreased after treatment with paraquat and that the remaining endosymbionts were exposed to high stress. The devised assay is a potential environmental monitoring method, applicable not only to P. bursaria but also to multicellular symbiotic units, such as corals.

APA, Harvard, Vancouver, ISO, and other styles

3

Souza, Lucas Santana, Josephine Solowiej-Wedderburn, Adriano Bonforti, and Eric Libby. "Modeling endosymbioses: Insights and hypotheses from theoretical approaches." PLOS Biology 22, no. 4 (April 10, 2024): e3002583. http://dx.doi.org/10.1371/journal.pbio.3002583.

Full text

Abstract:

Endosymbiotic relationships are pervasive across diverse taxa of life, offering key avenues for eco-evolutionary dynamics. Although a variety of experimental and empirical frameworks have shed light on critical aspects of endosymbiosis, theoretical frameworks (mathematical models) are especially well-suited for certain tasks. Mathematical models can integrate multiple factors to determine the net outcome of endosymbiotic relationships, identify broad patterns that connect endosymbioses with other systems, simplify biological complexity, generate hypotheses for underlying mechanisms, evaluate different hypotheses, identify constraints that limit certain biological interactions, and open new lines of inquiry. This Essay highlights the utility of mathematical models in endosymbiosis research, particularly in generating relevant hypotheses. Despite their limitations, mathematical models can be used to address known unknowns and discover unknown unknowns.

APA, Harvard, Vancouver, ISO, and other styles

4

Archibald, John M. "Genomic perspectives on the birth and spread of plastids." Proceedings of the National Academy of Sciences 112, no. 33 (April 20, 2015): 10147–53. http://dx.doi.org/10.1073/pnas.1421374112.

Full text

Abstract:

The endosymbiotic origin of plastids from cyanobacteria was a landmark event in the history of eukaryotic life. Subsequent to the evolution of primary plastids, photosynthesis spread from red and green algae to unrelated eukaryotes by secondary and tertiary endosymbiosis. Although the movement of cyanobacterial genes from endosymbiont to host is well studied, less is known about the migration of eukaryotic genes from one nucleus to the other in the context of serial endosymbiosis. Here I explore the magnitude and potential impact of nucleus-to-nucleus endosymbiotic gene transfer in the evolution of complex algae, and the extent to which such transfers compromise our ability to infer the deep structure of the eukaryotic tree of life. In addition to endosymbiotic gene transfer, horizontal gene transfer events occurring before, during, and after endosymbioses further confound our efforts to reconstruct the ancient mergers that forged multiple lines of photosynthetic microbial eukaryotes.

APA, Harvard, Vancouver, ISO, and other styles

5

O’Malley, Maureen A. "Endosymbiosis and its implications for evolutionary theory." Proceedings of the National Academy of Sciences 112, no. 33 (April 16, 2015): 10270–77. http://dx.doi.org/10.1073/pnas.1421389112.

Full text

Abstract:

Historically, conceptualizations of symbiosis and endosymbiosis have been pitted against Darwinian or neo-Darwinian evolutionary theory. In more recent times, Lynn Margulis has argued vigorously along these lines. However, there are only shallow grounds for finding Darwinian concepts or population genetic theory incompatible with endosymbiosis. But is population genetics sufficiently explanatory of endosymbiosis and its role in evolution? Population genetics “follows” genes, is replication-centric, and is concerned with vertically consistent genetic lineages. It may also have explanatory limitations with regard to macroevolution. Even so, asking whether population genetics explains endosymbiosis may have the question the wrong way around. We should instead be asking how explanatory of evolution endosymbiosis is, and exactly which features of evolution it might be explaining. This paper will discuss how metabolic innovations associated with endosymbioses can drive evolution and thus provide an explanatory account of important episodes in the history of life. Metabolic explanations are both proximate and ultimate, in the same way genetic explanations are. Endosymbioses, therefore, point evolutionary biology toward an important dimension of evolutionary explanation.

APA, Harvard, Vancouver, ISO, and other styles

6

Veloz, Tomas, and Daniela Flores. "Reaction Network Modeling of Complex Ecological Interactions: Endosymbiosis and Multilevel Regulation." Complexity 2021 (August 7, 2021): 1–12. http://dx.doi.org/10.1155/2021/8760937.

Full text

Abstract:

Endosymbiosis is a type of symbiosis where one species of microscopic scale inhabits the cell of another species of a larger scale, such that the exchange of metabolic byproducts produces mutual benefit. These benefits can occur at different biological levels. For example, endosymbiosis promotes efficiency of the cell metabolism, cell replication, and the generation of a macroscopic layer that protects the organism from its predators. Therefore, modeling endosymbiosis requires a complex-systems and multilevel approach. We propose a model of endosymbiosis based on reaction networks, where species of the reaction network represent either ecological species, resources, or conditions for the ecological interactions to happen, and the endosymbiotic interaction mechanisms are represented by different sequences of reactions (processes) in the reaction network. As an example, we develop a toy model of the coral endosymbiotic interaction. The model considers two reaction networks, representing biochemical traffic and cellular proliferation levels, respectively. In addition, the model incorporates top-down and bottom-up regulation mechanisms that stabilizes the endosymbiotic interaction.

APA, Harvard, Vancouver, ISO, and other styles

7

Schreiber, Mona, and Sven B. Gould. "Antreiber evolutionärer Transformation: die Endosymbiose." BIOspektrum 27, no. 7 (November 2021): 701–4. http://dx.doi.org/10.1007/s12268-021-1670-9.

Full text

Abstract:

AbstractEndosymbiosis is a transformative force of evolution. Endosymbionts established billions of years ago shaped the face of earth and more recent ones take up intriguing new duties. Benefits of exploring endosymbioses are manyfold: we gain a better understanding of fundamental biological principles such as why prokaryotes fail to frequently evolve eukaryote-like complexity and can learn how beneficial partnerships are established. 50 years ago, endosymbiosis was met with scepticism, but is now accepted as a phenomenon responsible for some of life’s biggest transitions.

APA, Harvard, Vancouver, ISO, and other styles

8

Jenkins, Benjamin H., Finlay Maguire, Guy Leonard, Joshua D. Eaton, Steven West, Benjamin E. Housden, David S. Milner, and Thomas A. Richards. "Emergent RNA–RNA interactions can promote stability in a facultative phototrophic endosymbiosis." Proceedings of the National Academy of Sciences 118, no. 38 (September 14, 2021): e2108874118. http://dx.doi.org/10.1073/pnas.2108874118.

Full text

Abstract:

Eukaryote–eukaryote endosymbiosis was responsible for the spread of chloroplast (plastid) organelles. Stability is required for the metabolic and genetic integration that drives the establishment of new organelles, yet the mechanisms that act to stabilize emergent endosymbioses—between two fundamentally selfish biological organisms—are unclear. Theory suggests that enforcement mechanisms, which punish misbehavior, may act to stabilize such interactions by resolving conflict. However, how such mechanisms can emerge in a facultative endosymbiosis has yet to be explored. Here, we propose that endosymbiont–host RNA–RNA interactions, arising from digestion of the endosymbiont population, can result in a cost to host growth for breakdown of the endosymbiosis. Using the model facultative endosymbiosis between Paramecium bursaria and Chlorella spp., we demonstrate that this mechanism is dependent on the host RNA-interference (RNAi) system. We reveal through small RNA (sRNA) sequencing that endosymbiont-derived messenger RNA (mRNA) released upon endosymbiont digestion can be processed by the host RNAi system into 23-nt sRNA. We predict multiple regions of shared sequence identity between endosymbiont and host mRNA, and demonstrate through delivery of synthetic endosymbiont sRNA that exposure to these regions can knock down expression of complementary host genes, resulting in a cost to host growth. This process of host gene knockdown in response to endosymbiont-derived RNA processing by host RNAi factors, which we term “RNAi collisions,” represents a mechanism that can promote stability in a facultative eukaryote–eukaryote endosymbiosis. Specifically, by imposing a cost for breakdown of the endosymbiosis, endosymbiont–host RNA–RNA interactions may drive maintenance of the symbiosis across fluctuating ecological conditions.

APA, Harvard, Vancouver, ISO, and other styles

9

Radzvilavicius, Arunas L., and Neil W. Blackstone. "Conflict and cooperation in eukaryogenesis: implications for the timing of endosymbiosis and the evolution of sex." Journal of The Royal Society Interface 12, no. 111 (October 2015): 20150584. http://dx.doi.org/10.1098/rsif.2015.0584.

Full text

Abstract:

Roughly 1.5–2.0 Gya, the eukaryotic cell evolved from an endosymbiosis of an archaeal host and proteobacterial symbionts. The timing of this endosymbiosis relative to the evolution of eukaryotic features remains subject to considerable debate, yet the evolutionary process itself constrains the timing of these events. Endosymbiosis entailed levels-of-selection conflicts, and mechanisms of conflict mediation had to evolve for eukaryogenesis to proceed. The initial mechanisms of conflict mediation (e.g. signalling with calcium and soluble adenylyl cyclase, substrate carriers, adenine nucleotide translocase, uncouplers) led to metabolic homeostasis in the eukaryotic cell. Later mechanisms (e.g. mitochondrial gene loss) contributed to the chimeric eukaryotic genome. These integral features of eukaryotes were derived because of, and therefore subsequent to, endosymbiosis. Perhaps the greatest opportunity for conflict arose with the emergence of eukaryotic sex, involving whole-cell fusion. A simple model demonstrates that competition on the lower level severely hinders the evolution of sex. Cytoplasmic mixing, however, is beneficial for non-cooperative endosymbionts, which could have used their aerobic metabolism to manipulate the life history of the host. While early evolution of sex may have facilitated symbiont acquisition, sex would have also destabilized the subsequent endosymbiosis. More plausibly, the evolution of sex and the true nucleus concluded the transition.

APA, Harvard, Vancouver, ISO, and other styles

10

Maire, Justin, Nicolas Parisot, Mariana Galvao Ferrarini, Agnès Vallier, Benjamin Gillet, Sandrine Hughes, Séverine Balmand, Carole Vincent-Monégat, Anna Zaidman-Rémy, and Abdelaziz Heddi. "Spatial and morphological reorganization of endosymbiosis during metamorphosis accommodates adult metabolic requirements in a weevil." Proceedings of the National Academy of Sciences 117, no. 32 (July 28, 2020): 19347–58. http://dx.doi.org/10.1073/pnas.2007151117.

Full text

Abstract:

Bacterial intracellular symbiosis (endosymbiosis) is widespread in nature and impacts many biological processes. In holometabolous symbiotic insects, metamorphosis entails a complete and abrupt internal reorganization that creates a constraint for endosymbiont transmission from larvae to adults. To assess how endosymbiosis copes—and potentially evolves—throughout this major host-tissue reorganization, we used the association between the cereal weevilSitophilus oryzaeand the bacteriumSodalis pierantoniusas a model system.S. pierantoniusare contained inside specialized host cells, the bacteriocytes, that group into an organ, the bacteriome. Cereal weevils require metabolic inputs from their endosymbiont, particularly during adult cuticle synthesis, when endosymbiont load increases dramatically. By combining dual RNA-sequencing analyses and cell imaging, we show that the larval bacteriome dissociates at the onset of metamorphosis and releases bacteriocytes that undergo endosymbiosis-dependent transcriptomic changes affecting cell motility, cell adhesion, and cytoskeleton organization. Remarkably, bacteriocytes turn into spindle cells and migrate along the midgut epithelium, thereby conveying endosymbionts to midgut sites where future mesenteric caeca will develop. Concomitantly, endosymbiont genes encoding a type III secretion system and a flagellum apparatus are transiently up-regulated while endosymbionts infect putative stem cells and enter their nuclei. Infected cells then turn into new differentiated bacteriocytes and form multiple new bacteriomes in adults. These findings show that endosymbiosis reorganization in a holometabolous insect relies on a synchronized host–symbiont molecular and cellular “choreography” and illustrates an adaptive feature that promotes bacteriome multiplication to match increased metabolic requirements in emerging adults.

APA, Harvard, Vancouver, ISO, and other styles

11

Wernegreen, Jennifer J. "Endosymbiosis." Current Biology 22, no. 14 (July 2012): R555—R561. http://dx.doi.org/10.1016/j.cub.2012.06.010.

Full text

APA, Harvard, Vancouver, ISO, and other styles

12

von der Dunk, Samuel H. A., Paulien Hogeweg, and Berend Snel. "Intracellular signaling in proto-eukaryotes evolves to alleviate regulatory conflicts of endosymbiosis." PLOS Computational Biology 20, no. 2 (February 9, 2024): e1011860. http://dx.doi.org/10.1371/journal.pcbi.1011860.

Full text

Abstract:

The complex eukaryotic cell resulted from a merger between simpler prokaryotic cells, yet the role of the mitochondrial endosymbiosis with respect to other eukaryotic innovations has remained under dispute. To investigate how the regulatory challenges associated with the endosymbiotic state impacted genome and network evolution during eukaryogenesis, we study a constructive computational model where two simple cells are forced into an obligate endosymbiosis. Across multiple in silico evolutionary replicates, we observe the emergence of different mechanisms for the coordination of host and symbiont cell cycles, stabilizing the endosymbiotic relationship. In most cases, coordination is implicit, without signaling between host and symbiont. Signaling only evolves when there is leakage of regulatory products between host and symbiont. In the fittest evolutionary replicate, the host has taken full control of the symbiont cell cycle through signaling, mimicking the regulatory dominance of the nucleus over the mitochondrion that evolved during eukaryogenesis.

APA, Harvard, Vancouver, ISO, and other styles

13

Bull, Lawrence, and Terence C. Fogarty. "Artificial Symbiogenesis." Artificial Life 2, no. 3 (April 1995): 269–92. http://dx.doi.org/10.1162/artl.1995.2.3.269.

Full text

Abstract:

Symbiosis is the phenomenon in which organisms of different species live together in close association, resulting in a raised level of fitness for one or more of the organisms. Symbiogenesis is the name given to the process by which symbiotic partners combine and unify—forming endosymbioses and then potentially transferring genetic material—giving rise to new morphologies and physiologies evolutionarily more advanced than their constituents. In this article we begin by using the NKC model of coevolution to examine endosymbiosis and its effect on the evolutionary performance of the partners involved. We are then able to suggest the conditions under which endosymbioses are more likely to occur and why; we find they emerge between organisms within a window of their respective “chaotic gas regimes” and hence that the association represents a more stable state for the partners. The conditions under which gene transfer is more likely to represent an advantage for such endosymbionts are then examined within the same model. We find that, providing a suitable pathway exists, such a process can lead to a more efficient genetic configuration for the symbionts within a window that overlaps that in which endosymbioses occur. Finally, the results are used as grounds for implementing symbiogenesis within artificial evolutionary multiagent systems.

APA, Harvard, Vancouver, ISO, and other styles

14

Nowack, Eva C. M. "Paulinella chromatophora – rethinking the transition from endosymbiont to organelle." Acta Societatis Botanicorum Poloniae 83, no. 4 (2014): 387–97. http://dx.doi.org/10.5586/asbp.2014.049.

Full text

Abstract:

Eukaryotes co-opted photosynthetic carbon fixation from prokaryotes by engulfing a cyanobacterium and stably integrating it as a photosynthetic organelle (plastid) in a process known as primary endosymbiosis. The sheer complexity of interactions between a plastid and the surrounding cell that started to evolve over 1 billion years ago, make it challenging to reconstruct intermediate steps in organelle evolution by studying extant plastids. Recently, the photosynthetic amoeba <em>Paulinella chromatophora</em> was identified as a much sought-after intermediate stage in the evolution of a photosynthetic organelle. This article reviews the current knowledge on this unique organism. In particular it describes how the interplay of reductive genome evolution, gene transfers, and trafficking of host-encoded proteins into the cyanobacterial endosymbiont contributed to transform the symbiont into a nascent photosynthetic organelle. Together with recent results from various other endosymbiotic associations a picture emerges that lets the targeting of host-encoded proteins into bacterial endosymbionts appear as an early step in the establishment of an endosymbiotic relationship that enables the host to gain control over the endosymbiont.

APA, Harvard, Vancouver, ISO, and other styles

15

Dinh, Christopher, Timothy Farinholt, Shigenori Hirose, Olga Zhuchenko, and Adam Kuspa. "Lectins modulate the microbiota of social amoebae." Science 361, no. 6400 (July 26, 2018): 402–6. http://dx.doi.org/10.1126/science.aat2058.

Full text

Abstract:

The social amoebaDictyostelium discoideummaintains a microbiome during multicellular development; bacteria are carried in migrating slugs and as endosymbionts within amoebae and spores. Bacterial carriage and endosymbiosis are induced by the secreted lectin discoidin I that binds bacteria, protects them from extracellular killing, and alters their retention within amoebae. This altered handling of bacteria also occurs with bacteria coated by plant lectins and leads to DNA transfer from bacteria to amoebae. Thus, lectins alter the cellular response ofD. discoideumto bacteria to establish the amoebae’s microbiome. Mammalian cells can also maintain intracellular bacteria when presented with bacteria coated with lectins, so heterologous lectins may induce endosymbiosis in animals. Our results suggest that endogenous or environmental lectins may influence microbiome homeostasis across eukaryotic phylogeny.

APA, Harvard, Vancouver, ISO, and other styles

16

Tribe, Michael A. "Endosymbiosis revisited." Journal of Biological Education 22, no. 3 (September 1988): 171–77. http://dx.doi.org/10.1080/00219266.1988.9654978.

Full text

APA, Harvard, Vancouver, ISO, and other styles

17

Geer Jr., Daniel E. "Digital Endosymbiosis." IEEE Security & Privacy Magazine 7, no. 3 (May 2009): 88. http://dx.doi.org/10.1109/msp.2009.63.

Full text

APA, Harvard, Vancouver, ISO, and other styles

18

Richardson, Susan L. "Endosymbiont change as a key innovation in the adaptive radiation of Soritida (Foraminifera)." Paleobiology 27, no. 2 (2001): 262–89. http://dx.doi.org/10.1666/0094-8373(2001)027<0262:ecaaki>2.0.co;2.

Full text

Abstract:

A phylogeny of 54 Recent and fossil species of Soritacea (Foraminifera) was used to test the hypothesis that endosymbiosis has driven the evolution of the clade. Endosymbiosis with photosynthetic eukaryotes is the plesiomorphic condition for the entire clade Soritacea. Living species dwell in tropical-subtropical, shallow-water habitats and are characterized by the possession of rhodophyte, chlorophyte, or dinophyte photosymbionts. Two distinct changes in endosymbiont type are recognized when endosymbiont type is mapped in the cladogram of Soritacea: (1) a change from rhodophyte to chlorophyte endosymbionts occurred in the stem lineage of the least inclusive clade containing New clade B, Orbiculinida, and Soritida; and (2) a change from chlorophyte to dinophyte endosymbionts occurred in the stem lineage of the least inclusive clade containing New clade G, New clade H, New clade I, Sorites, Amphisorus, and Orbitolites. When habitat and ontogeny are optimized on the cladogram of Soritida, the acquisition of dinophyte endosymbionts appears as a key innovation that facilitated a switch in habitat from free-living to attached living on nonphytal and phytal substrata. A subsequent change in the attached habitat from nonphytal to predominantly phytal (seagrasses and macroalgae) substrata is accompanied by a peramorphic trend in the megalospheric tests. The diversification (adaptive radiation) of the crown Soritida subclade resulted from the interplay between the acquisition of a key innovation (dinophyte endosymbionts) and the subsequent change in the ecology of the group (radiation to phytal substrates).

APA, Harvard, Vancouver, ISO, and other styles

19

Keeling, Patrick J. "The endosymbiotic origin, diversification and fate of plastids." Philosophical Transactions of the Royal Society B: Biological Sciences 365, no. 1541 (March 12, 2010): 729–48. http://dx.doi.org/10.1098/rstb.2009.0103.

Full text

Abstract:

Plastids and mitochondria each arose from a single endosymbiotic event and share many similarities in how they were reduced and integrated with their host. However, the subsequent evolution of the two organelles could hardly be more different: mitochondria are a stable fixture of eukaryotic cells that are neither lost nor shuffled between lineages, whereas plastid evolution has been a complex mix of movement, loss and replacement. Molecular data from the past decade have substantially untangled this complex history, and we now know that plastids are derived from a single endosymbiotic event in the ancestor of glaucophytes, red algae and green algae (including plants). The plastids of both red algae and green algae were subsequently transferred to other lineages by secondary endosymbiosis. Green algal plastids were taken up by euglenids and chlorarachniophytes, as well as one small group of dinoflagellates. Red algae appear to have been taken up only once, giving rise to a diverse group called chromalveolates. Additional layers of complexity come from plastid loss, which has happened at least once and probably many times, and replacement. Plastid loss is difficult to prove, and cryptic, non-photosynthetic plastids are being found in many non-photosynthetic lineages. In other cases, photosynthetic lineages are now understood to have evolved from ancestors with a plastid of different origin, so an ancestral plastid has been replaced with a new one. Such replacement has taken place in several dinoflagellates (by tertiary endosymbiosis with other chromalveolates or serial secondary endosymbiosis with a green alga), and apparently also in two rhizarian lineages: chlorarachniophytes and Paulinella (which appear to have evolved from chromalveolate ancestors). The many twists and turns of plastid evolution each represent major evolutionary transitions, and each offers a glimpse into how genomes evolve and how cells integrate through gene transfers and protein trafficking.

APA, Harvard, Vancouver, ISO, and other styles

20

Gornik, Sebastian G., Febrimarsa, Andrew M. Cassin, James I. MacRae, Abhinay Ramaprasad, Zineb Rchiad, Malcolm J. McConville, et al. "Endosymbiosis undone by stepwise elimination of the plastid in a parasitic dinoflagellate." Proceedings of the National Academy of Sciences 112, no. 18 (April 20, 2015): 5767–72. http://dx.doi.org/10.1073/pnas.1423400112.

Full text

Abstract:

Organelle gain through endosymbiosis has been integral to the origin and diversification of eukaryotes, and, once gained, plastids and mitochondria seem seldom lost. Indeed, discovery of nonphotosynthetic plastids in many eukaryotes—notably, the apicoplast in apicomplexan parasites such as the malaria pathogen Plasmodium—highlights the essential metabolic functions performed by plastids beyond photosynthesis. Once a cell becomes reliant on these ancillary functions, organelle dependence is apparently difficult to overcome. Previous examples of endosymbiotic organelle loss (either mitochondria or plastids), which have been invoked to explain the origin of eukaryotic diversity, have subsequently been recognized as organelle reduction to cryptic forms, such as mitosomes and apicoplasts. Integration of these ancient symbionts with their hosts has been too well developed to reverse. Here, we provide evidence that the dinoflagellate Hematodinium sp., a marine parasite of crustaceans, represents a rare case of endosymbiotic organelle loss by the elimination of the plastid. Extensive RNA and genomic sequencing data provide no evidence for a plastid organelle, but, rather, reveal a metabolic decoupling from known plastid functions that typically impede organelle loss. This independence has been achieved through retention of ancestral anabolic pathways, enzyme relocation from the plastid to the cytosol, and metabolic scavenging from the parasite’s host. Hematodinium sp. thus represents a further dimension of endosymbiosis—life after the organelle.

APA, Harvard, Vancouver, ISO, and other styles

21

Thornhill, Daniel J., Kevin T. Fielman, Scott R. Santos, and Kenneth M. Halanych. "Siboglinid-bacteria endosymbiosis." Communicative & Integrative Biology 1, no. 2 (October 2008): 163–66. http://dx.doi.org/10.4161/cib.1.2.7108.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Harmer, Jane, Vyacheslav Yurchenko, Anna Nenarokova, Julius Lukeš, and Michael L. Ginger. "Farming, slaving and enslavement: histories of endosymbioses during kinetoplastid evolution." Parasitology 145, no. 10 (June 13, 2018): 1311–23. http://dx.doi.org/10.1017/s0031182018000781.

Full text

Abstract:

AbstractParasitic trypanosomatids diverged from free-living kinetoplastid ancestors several hundred million years ago. These parasites are relatively well known, due in part to several unusual cell biological and molecular traits and in part to the significance of a few – pathogenic Leishmania and Trypanosoma species – as aetiological agents of serious neglected tropical diseases. However, the majority of trypanosomatid biodiversity is represented by osmotrophic monoxenous parasites of insects. In two lineages, novymonads and strigomonads, osmotrophic lifestyles are supported by cytoplasmic endosymbionts, providing hosts with macromolecular precursors and vitamins. Here we discuss the two independent origins of endosymbiosis within trypanosomatids and subsequently different evolutionary trajectories that see entrainment vs tolerance of symbiont cell divisions cycles within those of the host. With the potential to inform on the transition to obligate parasitism in the trypanosomatids, interest in the biology and ecology of free-living, phagotrophic kinetoplastids is beginning to enjoy a renaissance. Thus, we take the opportunity to additionally consider the wider relevance of endosymbiosis during kinetoplastid evolution, including the indulged lifestyle and reductive evolution of basal kinetoplastid Perkinsela.

APA, Harvard, Vancouver, ISO, and other styles

23

FUKATSU, TAKEMA. "Endosymbiosis of Aphids with Microorganisms: a Model Case of Dynamic Endosymbiotic Evolution." Plant Species Biology 9, no. 3 (December 1994): 145–54. http://dx.doi.org/10.1111/j.1442-1984.1994.tb00095.x.

Full text

APA, Harvard, Vancouver, ISO, and other styles

24

Inagaki, Y., J. B. Dacks, W. F. Doolittle, K. I. Watanabe, and T. Ohama. "Evolutionary relationship between dinoflagellates bearing obligate diatom endosymbionts: insight into tertiary endosymbiosis." International Journal of Systematic and Evolutionary Microbiology 50, no. 6 (November 1, 2000): 2075–81. http://dx.doi.org/10.1099/00207713-50-6-2075.

Full text

APA, Harvard, Vancouver, ISO, and other styles

25

Hehenberger, Elisabeth, Rebecca J. Gast, and Patrick J. Keeling. "A kleptoplastidic dinoflagellate and the tipping point between transient and fully integrated plastid endosymbiosis." Proceedings of the National Academy of Sciences 116, no. 36 (August 19, 2019): 17934–42. http://dx.doi.org/10.1073/pnas.1910121116.

Full text

Abstract:

Plastid endosymbiosis has been a major force in the evolution of eukaryotic cellular complexity, but how endosymbionts are integrated is still poorly understood at a mechanistic level. Dinoflagellates, an ecologically important protist lineage, represent a unique model to study this process because dinoflagellate plastids have repeatedly been reduced, lost, and replaced by new plastids, leading to a spectrum of ages and integration levels. Here we describe deep-transcriptomic analyses of the Antarctic Ross Sea dinoflagellate (RSD), which harbors long-term but temporary kleptoplasts stolen from haptophyte prey, and is closely related to dinoflagellates with fully integrated plastids derived from different haptophytes. In some members of this lineage, called the Kareniaceae, their tertiary haptophyte plastids have crossed a tipping point to stable integration, but RSD has not, and may therefore reveal the order of events leading up to endosymbiotic integration. We show that RSD has retained its ancestral secondary plastid and has partitioned functions between this plastid and the kleptoplast. It has also obtained genes for kleptoplast-targeted proteins via horizontal gene transfer (HGT) that are not derived from the kleptoplast lineage. Importantly, many of these HGTs are also found in the related species with fully integrated plastids, which provides direct evidence that genetic integration preceded organelle fixation. Finally, we find that expression of kleptoplast-targeted genes is unaffected by environmental parameters, unlike prey-encoded homologs, suggesting that kleptoplast-targeted HGTs have adapted to posttranscriptional regulation mechanisms of the host.

APA, Harvard, Vancouver, ISO, and other styles

26

Deschamps, Philippe. "Primary endosymbiosis: have cyanobacteria and Chlamydiae ever been roommates?" Acta Societatis Botanicorum Poloniae 83, no. 4 (2014): 291–302. http://dx.doi.org/10.5586/asbp.2014.048.

Full text

Abstract:

Eukaryotes acquired the ability to process photosynthesis by engulfing a cyanobacterium and transforming it into a genuine organelle called the plastid. This event, named primary endosymbiosis, occurred once more than a billion years ago, and allowed the emergence of the Archaeplastida, a monophyletic supergroup comprising the green algae and plants, the red algae and the glaucophytes. Of the other known cases of symbiosis between cyanobacteria and eukaryotes, none has achieved a comparable level of cell integration nor reached the same evolutionary and ecological success than primary endosymbiosis did. Reasons for this unique accomplishment are still unknown and difficult to comprehend. The exploration of plant genomes has revealed a considerable amount of genes closely related to homologs of Chlamydiae bacteria, and probably acquired by horizontal gene transfer. Several studies have proposed that these transferred genes, which are mostly involved in the functioning of the plastid, may have helped the settlement of primary endosymbiosis. Some of these studies propose that Chlamydiae and cyanobacterial symbionts coexisted in the eukaryotic host of the primary endosymbiosis, and that Chlamydiae provided solutions for the metabolic symbiosis between the cyanobacterium and the host, ensuring the success of primary endosymbiosis. In this review, I present a reevaluation of the contribution of Chlamydiae genes to the genome of Archaeplastida and discuss the strengths and weaknesses of this tripartite model for primary endosymbiosis.

APA, Harvard, Vancouver, ISO, and other styles

27

Mackiewicz, Paweł, and Przemysław Gagat. "Monophyly of Archaeplastida supergroup and relationships among its lineages in the light of phylogenetic and phylogenomic studies. Are we close to a consensus?" Acta Societatis Botanicorum Poloniae 83, no. 4 (2014): 263–80. http://dx.doi.org/10.5586/asbp.2014.044.

Full text

Abstract:

One of the key evolutionary events on the scale of the biosphere was an endosymbiosis between a heterotrophic eukaryote and a cyanobacterium, resulting in a primary plastid. Such an organelle is characteristic of three eukaryotic lineages, glaucophytes, red algae and green plants. The three groups are usually united under the common name Archaeplastida or Plantae in modern taxonomic classifications, which indicates they are considered monophyletic. The methods generally used to verify this monophyly are phylogenetic analyses. In this article we review up-to-date results of such analyses and discussed their inconsistencies. Although phylogenies of plastid genes suggest a single primary endosymbiosis, which is assumed to mean a common origin of the Archaeplastida, different phylogenetic trees based on nuclear markers show monophyly, paraphyly, polyphyly or unresolved topologies of Archaeplastida hosts. The difficulties in reconstructing host cell relationships could result from stochastic and systematic biases in data sets, including different substitution rates and patterns, gene paralogy and horizontal/endosymbiotic gene transfer into eukaryotic lineages, which attract Archaeplastida in phylogenetic trees. Based on results to date, it is neither possible to confirm nor refute alternative evolutionary scenarios to a single primary endosymbiosis. Nevertheless, if trees supporting monophyly are considered, relationships inferred among Archaeplastida lineages can be discussed. Phylogenetic analyses based on nuclear genes clearly show the earlier divergence of glaucophytes from red algae and green plants. Plastid genes suggest a more complicated history, but at least some studies are congruent with this concept. Additional research involving more representatives of glaucophytes and many understudied lineages of Eukaryota can improve inferring phylogenetic relationships related to the Archaeplastida. In addition, alternative approaches not directly dependent on phylogenetic methods should be developed.

APA, Harvard, Vancouver, ISO, and other styles

28

van der Giezen, M. "Endosymbiosis: past and present." Heredity 95, no. 5 (May 25, 2005): 335–36. http://dx.doi.org/10.1038/sj.hdy.6800703.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

Jeon, Kwang W. "Bacterial endosymbiosis in amoebae." Trends in Cell Biology 5, no. 3 (March 1995): 137–40. http://dx.doi.org/10.1016/s0962-8924(00)88966-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Whitfield, J. B. "Parasitoids, polydnaviruses and endosymbiosis." Parasitology Today 6, no. 12 (December 1990): 381–84. http://dx.doi.org/10.1016/0169-4758(90)90146-u.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Valdivia, Raphael H., and Joseph Heitman. "Endosymbiosis: The Evil within." Current Biology 17, no. 11 (June 2007): R408—R410. http://dx.doi.org/10.1016/j.cub.2007.04.001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Ishikawa, Masakazu, Ikuko Yuyama, Hiroshi Shimizu, Masafumi Nozawa, Kazuho Ikeo, and Takashi Gojobori. "Different Endosymbiotic Interactions in Two Hydra Species Reflect the Evolutionary History of Endosymbiosis." Genome Biology and Evolution 8, no. 7 (June 19, 2016): 2155–63. http://dx.doi.org/10.1093/gbe/evw142.

Full text

APA, Harvard, Vancouver, ISO, and other styles

33

Moon, Eun-Kyung, So-Min Park, Ki-Back Chu, Fu-Shi Quan, and Hyun-Hee Kong. "Differentially Expressed Gene Profile of Acanthamoeba castellanii Induced by an Endosymbiont Legionella pneumophila." Korean Journal of Parasitology 59, no. 1 (February 19, 2021): 67–75. http://dx.doi.org/10.3347/kjp.2021.59.1.67.

Full text

Abstract:

Legionella pneumophila is an opportunistic pathogen that survives and proliferates within protists such as Acanthamoeba spp. in environment. However, intracellular pathogenic endosymbiosis and its implications within Acanthamoeba spp. remain poorly understood. In this study, RNA sequencing analysis was used to investigate transcriptional changes in A. castellanii in response to L. pneumophila infection. Based on RNA sequencing data, we identified 1,211 upregulated genes and 1,131 downregulated genes in A. castellanii infected with L. pneumophila for 12 hr. After 24 hr, 1,321 upregulated genes and 1,379 downregulated genes were identified. Gene ontology (GO) analysis revealed that L. pneumophila endosymbiosis enhanced hydrolase activity, catalytic activity, and DNA binding while reducing oxidoreductase activity in the molecular function (MF) domain. In particular, multiple genes associated with the GO term ‘integral component of membrane’ were downregulated during endosymbiosis. The endosymbiont also induced differential expression of various methyltransferases and acetyltransferases in A. castellanii. Findings herein are may significantly contribute to understanding endosymbiosis of L. pneumophila within A. castellanii.

APA, Harvard, Vancouver, ISO, and other styles

34

DUCHATEAU-NGUYEN, GUILLEMETTE, GÉRARD WEISBUCH, and LUCA PELITI. "A COMPARTMENTAL MODEL OF ENDOSYMBIOSIS." Journal of Biological Systems 03, no. 03 (September 1995): 867–88. http://dx.doi.org/10.1142/s0218339095000782.

Full text

Abstract:

In a previous paper we showed that emergence of mutualism is made possible by selective recognition processes which allow the host to discriminate true symbionts from commensalists. In hydra/algae associations, algae are first ingested in the apex of digestive cells and then migrate to their basis. Both processes are selective.We extend here the previous differential model to a compartmental model and study the role of the two selection processes.

APA, Harvard, Vancouver, ISO, and other styles

35

Wernegreen, Jennifer J. "Endosymbiosis: Lessons in Conflict Resolution." PLoS Biology 2, no. 3 (March 16, 2004): e68. http://dx.doi.org/10.1371/journal.pbio.0020068.

Full text

APA, Harvard, Vancouver, ISO, and other styles

36

SLABAS, T. "Galactolipid biosynthesis genes and endosymbiosis." Trends in Plant Science 2, no. 5 (May 1997): 161–62. http://dx.doi.org/10.1016/s1360-1385(97)01029-7.

Full text

APA, Harvard, Vancouver, ISO, and other styles

37

Aanen, Duur K., and Paul Eggleton. "Symbiogenesis: Beyond the endosymbiosis theory?" Journal of Theoretical Biology 434 (December 2017): 99–103. http://dx.doi.org/10.1016/j.jtbi.2017.08.001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

38

Dodwell, Lucy. "Gallery: Colourful painting illustrates endosymbiosis." New Scientist 200, no. 2681 (November 2008): 46. http://dx.doi.org/10.1016/s0262-4079(08)62835-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

39

KUTSCHERA, U. "Endosymbiosis, cell evolution, and speciation." Theory in Biosciences 124, no. 1 (August 15, 2005): 1–24. http://dx.doi.org/10.1016/j.thbio.2005.04.001.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Archibald, John M. "Endosymbiosis and Eukaryotic Cell Evolution." Current Biology 25, no. 19 (October 2015): R911—R921. http://dx.doi.org/10.1016/j.cub.2015.07.055.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Keeling, Patrick J. "Endosymbiosis: Bacteria Sharing the Load." Current Biology 21, no. 16 (August 2011): R623—R624. http://dx.doi.org/10.1016/j.cub.2011.06.061.

Full text

APA, Harvard, Vancouver, ISO, and other styles

42

Oldroyd, G. E. D., M. J. Harrison, and U. Paszkowski. "Reprogramming Plant Cells for Endosymbiosis." Science 324, no. 5928 (May 7, 2009): 753–54. http://dx.doi.org/10.1126/science.1171644.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Sibbald, Shannon J., and John M. Archibald. "Genomic Insights into Plastid Evolution." Genome Biology and Evolution 12, no. 7 (May 13, 2020): 978–90. http://dx.doi.org/10.1093/gbe/evaa096.

Full text

Abstract:

Abstract The origin of plastids (chloroplasts) by endosymbiosis stands as one of the most important events in the history of eukaryotic life. The genetic, biochemical, and cell biological integration of a cyanobacterial endosymbiont into a heterotrophic host eukaryote approximately a billion years ago paved the way for the evolution of diverse algal groups in a wide range of aquatic and, eventually, terrestrial environments. Plastids have on multiple occasions also moved horizontally from eukaryote to eukaryote by secondary and tertiary endosymbiotic events. The overall picture of extant photosynthetic diversity can best be described as “patchy”: Plastid-bearing lineages are spread far and wide across the eukaryotic tree of life, nested within heterotrophic groups. The algae do not constitute a monophyletic entity, and understanding how, and how often, plastids have moved from branch to branch on the eukaryotic tree remains one of the most fundamental unsolved problems in the field of cell evolution. In this review, we provide an overview of recent advances in our understanding of the origin and spread of plastids from the perspective of comparative genomics. Recent years have seen significant improvements in genomic sampling from photosynthetic and nonphotosynthetic lineages, both of which have added important pieces to the puzzle of plastid evolution. Comparative genomics has also allowed us to better understand how endosymbionts become organelles.

APA, Harvard, Vancouver, ISO, and other styles

44

Wagner, Daniel, Xavier Pochon, Leslie Irwin, Robert J. Toonen, and Ruth D. Gates. "Azooxanthellate? Most Hawaiian black corals contain Symbiodinium." Proceedings of the Royal Society B: Biological Sciences 278, no. 1710 (October 20, 2010): 1323–28. http://dx.doi.org/10.1098/rspb.2010.1681.

Full text

Abstract:

The ecological success of shallow-water reef-building corals (Hexacorallia: Scleractinia) is framed by their intimate endosymbiosis with photosynthetic dinoflagellates in the genus Symbiodinium (zooxanthellae). In contrast, the closely related black corals (Hexacorallia: Anthipatharia) are described as azooxanthellate (lacking Symbiodinium ), a trait thought to reflect their preference for low-light environments that do not support photosynthesis. We examined 14 antipatharian species collected between 10 and 396 m from Hawai'i and Johnston Atoll for the presence of Symbiodinium using molecular typing and histology. Symbiodinium internal transcribed spacer-2 (ITS-2) region sequences were retrieved from 43 per cent of the antipatharian samples and 71 per cent of the examined species, and across the entire depth range. The ITS-2 sequences were identical or very similar to those commonly found in shallow-water scleractinian corals throughout the Pacific. Histological analyses revealed low densities of Symbiodinium cells inside antipatharian gastrodermal tissues (0–92 cells mm −3 ), suggesting that the Symbiodinium are endosymbiotic. These findings confirm that the capacity to engage in endosymbiosis with Symbiodinium is evolutionarily conserved across the cnidarian subclass Hexacorallia, and that antipatharians associate with Symbiodinium types found in shallow-water scleractinians. This study represents the deepest record for Symbiodinium to date, and suggests that some members of this dinoflagellate genus have extremely diverse habitat preferences and broad environmental ranges.

APA, Harvard, Vancouver, ISO, and other styles

45

Kondo, Natsuko, Masakazu Shimada, and Takema Fukatsu. "Infection density of Wolbachia endosymbiont affected by co-infection and host genotype." Biology Letters 1, no. 4 (July 13, 2005): 488–91. http://dx.doi.org/10.1098/rsbl.2005.0340.

Full text

Abstract:

Infection density is among the most important factors for understanding the biological effects of Wolbachia and other endosymbionts on their hosts. To gain insight into the mechanisms of infection density regulation, we investigated the adzuki bean beetles Callosobruchus chinensis and their Wolbachia endosymbionts. Double-infected, single-infected and uninfected host strains with controlled nuclear genetic backgrounds were generated by introgression, and infection densities in these strains were evaluated by a quantitative polymerase chain reaction technique. Our study revealed previously unknown aspects of Wolbachia density regulation: (i) the identification of intra-specific host genotypes that affect Wolbachia density differently and (ii) the suppression of Wolbachia density by co-infecting Wolbachia strains. These findings shed new light on symbiont–symbiont and host–symbiont interactions in the Wolbachia –insect endosymbiosis and strongly suggest that Wolbachia density is determined through a complex interaction between host genotype, symbiont genotype and other factors.

APA, Harvard, Vancouver, ISO, and other styles

46

Youle, Richard J. "Mitochondria—Striking a balance between host and endosymbiont." Science 365, no. 6454 (August 15, 2019): eaaw9855. http://dx.doi.org/10.1126/science.aaw9855.

Full text

Abstract:

Mitochondria are organelles with their own genome that arose from α-proteobacteria living within single-celled Archaea more than a billion years ago. This step of endosymbiosis offered tremendous opportunities for energy production and metabolism and allowed the evolution of fungi, plants, and animals. However, less appreciated are the downsides of this endosymbiosis. Coordinating gene expression between the mitochondrial genomes and the nuclear genome is imprecise and can lead to proteotoxic stress. The clonal reproduction of mitochondrial DNA requires workarounds to avoid mutational meltdown. In metazoans that developed innate immune pathways to thwart bacterial and viral infections, mitochondrial components can cross-react with pathogen sensors and invoke inflammation. Here, I focus on the numerous and elegant quality control processes that compensate for or mitigate these challenges of endosymbiosis.

APA, Harvard, Vancouver, ISO, and other styles

47

Martin, William F., Sriram Garg, and Verena Zimorski. "Endosymbiotic theories for eukaryote origin." Philosophical Transactions of the Royal Society B: Biological Sciences 370, no. 1678 (September 26, 2015): 20140330. http://dx.doi.org/10.1098/rstb.2014.0330.

Full text

Abstract:

For over 100 years, endosymbiotic theories have figured in thoughts about the differences between prokaryotic and eukaryotic cells. More than 20 different versions of endosymbiotic theory have been presented in the literature to explain the origin of eukaryotes and their mitochondria. Very few of those models account for eukaryotic anaerobes. The role of energy and the energetic constraints that prokaryotic cell organization placed on evolutionary innovation in cell history has recently come to bear on endosymbiotic theory. Only cells that possessed mitochondria had the bioenergetic means to attain eukaryotic cell complexity, which is why there are no true intermediates in the prokaryote-to-eukaryote transition. Current versions of endosymbiotic theory have it that the host was an archaeon (an archaebacterium), not a eukaryote. Hence the evolutionary history and biology of archaea increasingly comes to bear on eukaryotic origins, more than ever before. Here, we have compiled a survey of endosymbiotic theories for the origin of eukaryotes and mitochondria, and for the origin of the eukaryotic nucleus, summarizing the essentials of each and contrasting some of their predictions to the observations. A new aspect of endosymbiosis in eukaryote evolution comes into focus from these considerations: the host for the origin of plastids was a facultative anaerobe.

APA, Harvard, Vancouver, ISO, and other styles

48

Patron, Nicola J., Matthew B. Rogers, and Patrick J. Keeling. "Gene Replacement of Fructose-1,6-Bisphosphate Aldolase Supports the Hypothesis of a Single Photosynthetic Ancestor of Chromalveolates." Eukaryotic Cell 3, no. 5 (October 2004): 1169–75. http://dx.doi.org/10.1128/ec.3.5.1169-1175.2004.

Full text

Abstract:

ABSTRACT Plastids (photosynthetic organelles of plants and algae) are known to have spread between eukaryotic lineages by secondary endosymbiosis, that is, by the uptake of a eukaryotic alga by another eukaryote. But the number of times this has taken place is controversial. This is particularly so in the case of eukaryotes with plastids derived from red algae, which are numerous and diverse. Despite their diversity, it has been suggested that all these eukaryotes share a recent common ancestor and that their plastids originated in a single endosymbiosis, the so-called “chromalveolate hypothesis.” Here we describe a novel molecular character that supports the chromalveolate hypothesis. Fructose-1,6-bisphosphate aldolase (FBA) is a glycolytic and Calvin cycle enzyme that exists as two nonhomologous types, class I and class II. Red algal plastid-targeted FBA is a class I enzyme related to homologues from plants and green algae, and it would be predicted that the plastid-targeted FBA from algae with red algal secondary endosymbionts should be related to this class I enzyme. However, we show that plastid-targeted FBA of heterokonts, cryptomonads, haptophytes, and dinoflagellates (all photosynthetic chromalveolates) are class II plastid-targeted enzymes, completely unlike those of red algal plastids. The chromalveolate enzymes form a strongly supported group in FBA phylogeny, and their common possession of this unexpected plastid characteristic provides new evidence for their close relationship and a common origin for their plastids.

APA, Harvard, Vancouver, ISO, and other styles

49

Mazzocca, Antonio. "The Systemic–Evolutionary Theory of the Origin of Cancer (SETOC): A New Interpretative Model of Cancer as a Complex Biological System." International Journal of Molecular Sciences 20, no. 19 (October 2, 2019): 4885. http://dx.doi.org/10.3390/ijms20194885.

Full text

Abstract:

The Systemic–Evolutionary Theory of Cancer (SETOC) is a recently proposed theory based on two important concepts: (i) Evolution, understood as a process of cooperation and symbiosis (Margulian-like), and (ii) The system, in terms of the integration of the various cellular components, so that the whole is greater than the sum of the parts, as in any complex system. The SETOC posits that cancer is generated by the de-emergence of the “eukaryotic cell system” and by the re-emergence of cellular subsystems such as archaea-like (genetic information) and/or prokaryotic-like (mitochondria) subsystems, featuring uncoordinated behaviors. One of the consequences is a sort of “cellular regression” towards ancestral or atavistic biological functions or behaviors similar to those of protists or unicellular organisms in general. This de-emergence is caused by the progressive breakdown of the endosymbiotic cellular subsystem integration (mainly, information = nucleus and energy = mitochondria) as a consequence of long-term injuries. Known cancer-promoting factors, including inflammation, chronic fibrosis, and chronic degenerative processes, cause prolonged damage that leads to the breakdown or failure of this form of integration/endosymbiosis. In normal cells, the cellular “subsystems” must be fully integrated in order to maintain the differentiated state, and this integration is ensured by a constant energy intake. In contrast, when organ or tissue damage occurs, the constant energy intake declines, leading, over time, to energy shortage, failure of endosymbiosis, and the de-differentiated state observed in dysplasia and cancer.

APA, Harvard, Vancouver, ISO, and other styles

50

Speijer, Dave. "Zombie ideas about early endosymbiosis: Which entry mechanisms gave us the “endo” in different endosymbionts?" BioEssays 43, no. 7 (May 19, 2021): 2100069. http://dx.doi.org/10.1002/bies.202100069.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Endosymbiosis'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles