Endosymbiosis
Mostrando 13-24 de 40 artigos, teses e dissertações.
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13. Genes for a microaerobically induced oxidase complex in Bradyrhizobium japonicum are essential for a nitrogen-fixing endosymbiosis.
We report the discovery of a Bradyrhizobium japonicum gene cluster (fixNOQP) in which mutations resulted in defective soybean root-nodule bacteroid development and symbiotic nitrogen fixation. The predicted, DNA-derived protein sequences suggested that FixN is a heme b and copper-binding oxidase subunit, FixO a monoheme cytochrome c, FixQ a polypeptide of 54
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14. Gene Replacement of Fructose-1,6-Bisphosphate Aldolase Supports the Hypothesis of a Single Photosynthetic Ancestor of Chromalveolates†
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
American Society for Microbiology.
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15. Sequence of Prochloron didemni atpBE and the inference of chloroplast origins.
The prochlorophytes, oxygenic photosynthetic prokaryotes containing chlorophylls a and b, have been put forward as descended from the organisms that gave rise to chloroplasts of green plants and algae by endosymbiosis, although this has always been controversial. To assess the phylogenetic position of the prochlorophyte Prochloron didemni, we have cloned and
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16. Evidence for the establishment of aphid-eubacterium endosymbiosis in an ancestor of four aphid families.
Aphids (superfamily Aphidoidea) contain eubacterial endosymbionts localized within specialized cells (mycetocytes). The endosymbionts are essential for the survival of the aphid hosts. Sequence analyses of the 16S rRNAs from endosymbionts of 11 aphid species from seven tribes and four families have indicated that the endosymbionts are monophyletic. Furthermo
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17. Type III secretion systems and the evolution of mutualistic endosymbiosis
The view that parasites can develop cooperative symbiotic relationships with their hosts is both appealing and widely held; however, there is no molecular genetic evidence of such a transition. Here we demonstrate that a mutualistic bacterial endosymbiont of grain weevils maintains and expresses inv/spa genes encoding a type III secretion system homologous t
National Academy of Sciences.
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18. Plant nuclear gene knockout reveals a role in plastid division for the homolog of the bacterial cell division protein FtsZ, an ancestral tubulin
Little is known about the division of eukaryotic cell organelles and up to now neither in animals nor in plants has a gene product been shown to mediate this process. A cDNA encoding a homolog of the bacterial cell division protein FtsZ, an ancestral tubulin, was isolated from the eukaryote Physcomitrella patens and used to disrupt efficiently the genomic lo
The National Academy of Sciences.
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19. Plant-like traits associated with metabolism of Trypanosoma parasites
Trypanosomatid parasites cause serious diseases among humans, livestock, and plants. They belong to the order of the Kinetoplastida and form, together with the Euglenida, the phylum Euglenozoa. Euglenoid algae possess plastids capable of photosynthesis, but plastids are unknown in trypanosomatids. Here we present molecular evidence that trypanosomatids posse
The National Academy of Sciences.
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20. An Arabidopsis Homolog of the Bacterial Cell Division Inhibitor SulA Is Involved in Plastid DivisionW⃞
Plastids have evolved from an endosymbiosis between a cyanobacterial symbiont and a eukaryotic host cell. Their division is mediated both by proteins of the host cell and conserved bacterial division proteins. Here, we identified a new component of the plastid division machinery, Arabidopsis thaliana SulA. Disruption of its cyanobacterial homolog (SSulA) in
American Society of Plant Biologists.
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21. Bacterial genome size reduction by experimental evolution
Bacterial evolution toward endosymbiosis with eukaryotic cells is associated with extensive bacterial genome reduction and loss of metabolic and regulatory capabilities. Here we examined the rate and process of genome reduction in the bacterium Salmonella enterica by a serial passage experimental evolution procedure. The initial rate of DNA loss was estimate
National Academy of Sciences.
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22. Nuclear Genes That Encode Mitochondrial Proteins for DNA and RNA Metabolism Are Clustered in the Arabidopsis GenomeW⃞
The plant mitochondrial genome is complex in structure, owing to a high degree of recombination activity that subdivides the genome and increases genetic variation. The replication activity of various portions of the mitochondrial genome appears to be nonuniform, providing the plant with an ability to modulate its mitochondrial genotype during development. T
American Society of Plant Biologists.
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23. Archaea and the prokaryote-to-eukaryote transition.
Since the late 1970s, determining the phylogenetic relationships among the contemporary domains of life, the Archaea (archaebacteria), Bacteria (eubacteria), and Eucarya (eukaryotes), has been central to the study of early cellular evolution. The two salient issues surrounding the universal tree of life are whether all three domains are monophyletic (i.e., a
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24. A nuclear gene of eubacterial origin in Euglena gracilis reflects cryptic endosymbioses during protist evolution.
Genes for glycolytic and Calvin-cycle glyceraldehyde-3-phosphate dehydrogenase (GAPDH) of higher eukaryotes derive from ancient gene duplications which occurred in eubacterial genomes; both were transferred to the nucleus during the course of endosymbiosis. We have cloned cDNAs encoding chloroplast and cytosolic GAPDH from the early-branching photosynthetic