Миксотриха парадокса: құрсақ ішіндегі симбиоз және ерекше құрылысы

Species of protozoan

Mixotricha paradoxa is a species of protozoan that lives inside the gut of the Australian termite species Mastotermes darwiniensis. It is composed of five different organisms: three bacterial ectosymbionts live on its surface for locomotion and at least one endosymbiont lives inside to help digest cellulose in wood to produce acetate for its host(s). Mixotricha mitochondria degenerated in hydrogenosomes and mitosomes and lost the ability to produce energy aerobically by oxidative phosphorylation. The name means "the paradoxical being with mixed up hairs" because this protist has both cilia and flagella, which was not supposed to be the case with protists where they were supposed to have one or the other but not both. Mixotricha is a large protozoan long and contains hundreds of thousands of bacteria.

Species of the order Trichomonadida typically have four to six flagella at the cell's apical pole, one of which is recurrent that is, it runs along a surface wave, giving the aspect of an undulating membrane. Mixotricha paradoxa have four weak flagella that serve as rudders. It has four large flagella at the front end, three pointing forwards and one backward. The acetate probably crosses the termite gut membrane to be digested later. The flagella and cilia are actually two different single celled organisms. The ciliate belongs to an archaic group that used to be called archezoa but this term is no longer in fashion. It has four weak flagella, which serve as a rudder. Each spirochaete has its own little emplacement, called a 'bracket'. Spirochetes move continuously forwards or backwards but when they are attached they move in one direction. It is a good example organism for symbiogenesis and nestedness. There are two spirochete and one rod bacteria on its surface, one endosymbiotic bacteria inside to digest cellulose and the host nucleus.