Mixotricha paradoxa
Encyclopedia
Mixotricha paradoxa is a species of protozoa
Protozoa
Protozoa are a diverse group of single-cells eukaryotic organisms, many of which are motile. Throughout history, protozoa have been defined as single-cell protists with animal-like behavior, e.g., movement...

n that lives inside the termite
Termite
Termites are a group of eusocial insects that, until recently, were classified at the taxonomic rank of order Isoptera , but are now accepted as the epifamily Termitoidae, of the cockroach order Blattodea...

 species Mastotermes darwiniensis and has multiple bacteria
Bacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

l symbionts. The name, given by the Australian biologist J.L. Sutherland, who first described Mixotricha in 1933,. means “the paradoxical being with mixed-up hairs”.

Symbiosis

Mixotricha forms many symbiotic relationships. Like its relatives, including Trichonympha
Trichonympha
Trichonympha is a genus of parabasalian protists that live in the intestines of many, if not most, termite species. They are symbiotes, in that they break down the cellulose in the wood and plant fibers their hosts eat....

, it lives in the gut of termites and helps them digest cellulose
Cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to over ten thousand β linked D-glucose units....

, a major component of the wood they eat. Without Mixotricha, its host termites could not survive.

Mixotricha forms mutualistic relationships with bacteria living inside the termite as well. While it has four anterior flagella, Mixotricha does not use them for locomotion, but more for steering. For locomotion, about 250,000 hairlike Treponema spirochetes
Treponema spirochetes
Treponema spirochetes is a species of helical bacteria known to be a cause of papillomatous digital dermatitis, a major cause of lameness in cattle. It is also closely related to Treponema pallidum, the pathogen which causes syphilis in humans....

, a species of helical
Helix
A helix is a type of smooth space curve, i.e. a curve in three-dimensional space. It has the property that the tangent line at any point makes a constant angle with a fixed line called the axis. Examples of helixes are coil springs and the handrails of spiral staircases. A "filled-in" helix – for...

 bacteria, are attached to the cell surface and provide the cell with cilia-like movements. Mixotricha also has rod-shaped bacteria in an ordered pattern on the surface of the cell. In addition it has spherical bacteria inside the cell; these endosymbionts function as mitochondria
Mitochondrion
In cell biology, a mitochondrion is a membrane-enclosed organelle found in most eukaryotic cells. These organelles range from 0.5 to 1.0 micrometers in diameter...

, which Mixotricha lacks. There are a total of four species of bacterial symbionts.

Genome

According to Margulis and Sagan (2001), Mixotricha have five genomes, as they form very close symbiotic relationships with four types of bacteria. They consider Mixotricha paradoxa the poster organism for symbiogenesis
Symbiogenesis
Symbiogenesis is the merging of two separate organisms to form a single new organism. The idea originated with Konstantin Mereschkowsky in his 1926 book Symbiogenesis and the Origin of Species, which proposed that chloroplasts originate from cyanobacteria captured by a protozoan...

. Hunt et al. (2001, 2002) also consider it a composite organism with five genomes.

External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
x
OK