''Novymonas esmeraldas'' is a protist and member of

flagellated A flagellum (; : flagella) (Latin for 'whip' or 'scourge') is a hair-like appendage that protrudes from certain plant and animal sperm cells, from fungal spores (zoospores), and from a wide range of microorganisms to provide motility. Many prot ...

trypanosomatid Trypanosomatida is a group of kinetoplastid unicellular organisms distinguished by having only a single flagellum. The name is derived from the Greek ''trypano'' (borer) and ''soma'' (body) because of the corkscrew-like motion of some trypanosoma ...

s. It is an

obligate parasite An obligate parasite or holoparasite is a parasitic organism that cannot complete its life-cycle without exploiting a suitable host. If an obligate parasite cannot obtain a host it will fail to reproduce. This is opposed to a facultative parasite, ...

in the

gastrointestinal tract The gastrointestinal tract (GI tract, digestive tract, alimentary canal) is the tract or passageway of the Digestion, digestive system that leads from the mouth to the anus. The tract is the largest of the body's systems, after the cardiovascula ...

of a bug, and is in turn a

host A host is a person responsible for guests at an event or for providing hospitality during it. Host may also refer to: Places * Host, Pennsylvania, a village in Berks County * Host Island, in the Wilhelm Archipelago, Antarctica People * ...

symbiotic Symbiosis (Ancient Greek : living with, companionship < : together; and ''bíōsis'': living) is any type of a close and long-term biolo ...

bacteria. It maintains strict mutualistic relationship with the bacteria as a sort of cell organelle (

endosymbiont An endosymbiont or endobiont is an organism that lives within the body or cells of another organism. Typically the two organisms are in a mutualism (biology), mutualistic relationship. Examples are nitrogen-fixing bacteria (called rhizobia), whi ...

) so that it cannot lead an independent life without the bacteria. Its discovery in 2016 suggests that it is a good model in the evolution of prokaryotes into eukaryotes by

symbiogenesis Symbiogenesis (endosymbiotic theory, or serial endosymbiotic theory) is the leading evolutionary theory of the origin of eukaryotic cells from prokaryotic organisms. The theory holds that mitochondria, plastids such as chloroplasts, and possibl ...

. The endosymbiotic bacterium was identified as member of the genus ''

Pandoraea ''Pandoraea'' is a genus of Gram-negative, non-spore-forming, motile bacteria with a single polar flagellum, of the family Burkholderiaceae and class Betaproteobacteria.eol http://eol.org/pages/98285/overview References

Burkholderiacea ...

.''

Discovery

''Novymonas esmeraldas'' was discovered from a bug, ''Niesthrea vincentii'', from Ecuador. The bug was collected in July 2008 near Atacames in Esmeraldas Province, hence, the protist bears the species name. The genus name is after

Frederick George Novy __NOTOC__ Frederick George Novy (December 9, 1864 – August 8, 1957) was an American bacteriologist, organic chemist, and instructor. Biography Born in Chicago, Illinois, the third son of Joseph Novy and his wife Frances, grew up on the West Si ...

, an American bacteriologist and parasitologist who pioneered studies of insect trypanosomatids, and described in 1907 the first known symbiont-harbouring trypanosomatid, later named ''

Strigomonas culicis ''Strigomonas culicis'' is a protist and member of flagellated trypanosomatids. It is an obligate parasite in the gastrointestinal tract of mosquito, and is in turn a host to symbiotic bacteria. It maintains strict mutualistic relationship w ...

.''

Biology

Protist

''Novymonas esmeraldas'' spends it life cycle in the intestine (hindgut) of the bug, ''Niesthrea vincentii.'' During its life cycle it exists in two morphological forms, free-swimming promastigote and sedentary choanomastigote. Promastigotes are elongated and measure about 10.9 to 18 μm in length and about 1.3 to 4.8 μm in width. They bear a single flagellum in front that is 7.8 to 19.5 μm long. Choanomastigotes are more spherical in shape measuring 4.5 to 9.7 μm long and 2.8 to 6.4 μm wide. The flagellum is longer measuring 8.6 and 20.4 μm. The nucleus is centrally located, and in front of it is the

kinetoplast A kinetoplast is a network of circular DNA (called kDNA) inside a mitochondrion that contains many copies of the mitochondrial genome. The most common kinetoplast structure is a disk, but they have been observed in other arrangements. Kinetoplasts ...

. The kinetoplast is arranged in a compact disk which measures between 553 and 938 nm in diameter and 114 to 213 nm in cross section.

Bacterium

The endosymbiont is a bacterium classified as (''

Candidatus In prokaryote nomenclature, ''Candidatus'' (abbreviated ''Ca.''; Latin for "candidate of Roman office") is used to name prokaryotic taxa that are well characterized but yet- uncultured. Contemporary sequencing approaches, such as 16S ribosomal R ...

'') Pandoraea novymonadis that belongs to Gram-negative rod-shaped β-proteobacteria in the family

Burkholderiaceae The Burkholderiaceae are a family of bacteria included in the order Burkholderiales.Garrity, George M.; Brenner, Don J.; Krieg, Noel R.; Staley, James T. (eds.) (2005). Bergey's Manual of Systematic Bacteriology, Volume Two: The Proteobacteria, ...

. Unlike in other symbiont-harbouring trypanosomatids such as ''Strigonomas culicis'', ''Kentomonas sorsogonicus'', and ''

Angomonas deanei ''Angomonas deanei'' is a flagellated trypanosomatid protozoan. As an obligate parasite, it infects the gastrointestinal tract of insects, and is in turn a host to symbiotic bacteria. The bacterial endosymbiont ''Ca.'' "''Kinetoplastibacterium ...

'', the division of the endosymbiont is not synchronized with the host. ''Novymonas'' cells can bear a different number of the endosymbionts, and some do not have the bacteria at all. This indicates that the symbiosis in ''Novymonas'' is more recent than in the case of the other endosymbiont-bearing trypanosomatids. However, in contrast to its related free-living bacteria, ''P. novymonadis'' has highly reduced genome, less genes and lower GC contents.

References

{{Taxonbar, from=Q100348303 Symbiosis Endosymbiotic events Kinetoplastids Euglenozoa genera