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

flagellated A flagellum (; ) is a hairlike appendage that protrudes from certain plant and animal sperm cells, and from a wide range of microorganisms to provide motility. Many protists with flagella are termed as flagellates. A microorganism may have fro ...

trypanosomatids. 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 digestive system that leads from the mouth to the anus. The GI tract contains all the major organ (biology), organs of the digestive syste ...

of a bug, and is in turn a host to

symbiotic Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...

bacteria. It maintains strict mutualistic relationship with the bacteria as a sort of cell organelle ( endosymbiont) 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. 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 Betaproteobacteria are a class of Gram-negative bacteria, and one of the ...

.''

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, 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 Flagellum, flagellated trypanosomatids. It is an obligate parasite in the gastrointestinal tract of mosquito, and is in turn a Host (biology), host to Symbiosis, symbiotic bacteria. It maintains ...

.''

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