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

trypanosomatid Trypanosomatida is a group of kinetoplastid excavates 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 trypanosomatid species ...

s. It is an obligate parasite in the gastrointestinal tract 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 People *Jim Host (born 1937), American businessman * Michel Host ...

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

endosymbiont An ''endosymbiont'' or ''endobiont'' is any organism that lives within the body or cells of another organism most often, though not always, in a mutualistic relationship. (The term endosymbiosis is from the Greek: ἔνδον ''endon'' "within ...

) 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 pos ...

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

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. Born in Chicago, Illinois, the third son of Joseph Novy and his wife Frances, grew up on the West Side, near t ...

, 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.''

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 large 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. Kinet ...

. 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'' (Latin for candidate of Roman office) is used to name prokaryotic phyla that are well characterized but yet-uncultured. Contemporary sequencing approaches, such as 16S sequencing or metagenomics, provide m ...

'') 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'', 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