endosymbiont

Examples of endosymbiont in the following topics:

• Genome Reduction

  • These organelles are descended from endosymbionts, which can only survive within the host cell and which the host cell likewise needs for survival.
  • A common explanation for these keen manipulative abilities is the compact and efficient genomic structure consistently found in obligate endosymbionts.
  • One obligate endosymbiont of psyllid, Candidatus Carsonella ruddii, has the smallest genome currently known among cellular organisms at 160kb.
  • The reductive evolution model has been proposed as an effort to define the genomic commonalities seen in all obligate endosymbionts.
  • Based on this model, it is clear that endosymbionts face different adaptive challenges than free-living species.

• The Evolution of Plastids

  • There is also, as with the case of mitochondria, strong evidence that many of the genes of the endosymbiont transferred to the nucleus.
  • This leads to the question of the possibility of a cell containing an endosymbiont to become engulfed itself, resulting in a secondary endosymbiosis .
  • Some of the major groups of algae became photosynthetic by secondary endosymbiosis; that is, by taking in either green algae or red algae as endosymbionts.
  • The chloroplasts contained within the green algal endosymbionts are capable of photosynthesis, making chlorarachniophytes photosynthetic.
  • The green algal endosymbiont also exhibits a stunted vestigial nucleus.

• Endophytes and Plants

  • An endophyte is an endosymbiont, often a bacterium or fungus, that lives within a plant for at least part of its life without causing apparent disease.
  • An endophyte is an endosymbiont, often a bacterium or fungus, that lives within a plant for at least part of its life without causing apparent disease .

• Endosymbiosis and the Evolution of Eukaryotes

  • Christian de Duve proposed that they may have been the first endosymbionts, allowing cells to withstand growing amounts of free molecular oxygen in the earth's atmosphere.
  • It is believed that over millennia these endosymbionts transferred some of their own DNA to the host cell's nucleus during the evolutionary transition from a symbiotic community to an instituted eukaryotic cell (called "serial endosymbiosis").
  • The cyanobacterial endosymbiont already had a double membrane.

• Sea Coral and Sea Anemone Zooxanthellae

  • The term was loosely used to refer to any golden-brown endosymbionts, including diatoms and other dinoflagellates.
  • Symbiodinium are known primarily for their role as mutualistic endosymbionts.

• Genome Evolution

  • Another beautiful example are endosymbiont species.
  • For instance, Polynucleobacter necessarius was first described as a cytoplasmic endosymbiont of the ciliate Euplotes aediculatus.
  • The latter species dies soon after being cured of the endosymbiont.
  • The endosymbionts have a significantly reduced genome when compared to their free-living relatives (1.56 Mbp vs. 2.16 Mbp).

• Endosymbiotic Theory and the Evolution of Eukaryotes

  • This occurs when one species is taken inside the cytoplasm of another species, which ultimately results in a genome consisting of genes from both the endosymbiont and the host.
  • This mechanism is an aspect of the Endosymbiont Theory, which is accepted by a majority of biologists as the mechanism whereby eukaryotic cells obtained their mitochondria and chloroplasts.
  • The double membrane would be a direct result of endosymbiosis, with the endosymbiont picking up the second membrane from the host as it was internalized.

• Epsilonproteobacteria

  • A member of the class Epsilonproteobacteria occurs as an endosymbiont in the large gills of the deep water sea snail Alviniconcha hessleri.

• Gammaproteobacteria

  • Phylogenetically, in the Enterobacteriales, several peptidoglycan-less insect endosymbionts form a sister clade to the Enterobacteriaceae, but since they are not validly described, this group is not officially a taxon; examples of these species are Sodalis, Buchnera, Wigglesworthia, Baumannia and Blochmannia.

• Verrucomicrobia

  • A number of as-yet uncultivated species have been identified in association with eukaryotic hosts including extrusive explosive ectosymbionts of protists and endosymbionts of nematodes residing in their gametes.