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Trypanosomatida#Promastigote

{{short description|Group of single-celled parasitic organisms}}

{{automatic taxobox

| name = Trypanosomes

| fossil_range = Albian to recent {{fossilrange|100|0}}

| image = Trypanosoma_cruzi_crithidia.jpeg

| image_caption = Trypanosoma cruzi

| display_parents = 2

| parent_authority = Kent 1880

| taxon = Trypanosomatidae

| authority = Doflein 1901

| subdivision_ranks = Subfamily

| subdivision =

}}

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 trypanosomatid species. All members are exclusively parasitic, found primarily in insects.{{cite journal |author=Podlipaev S |title=The more insect trypanosomatids under study-the more diverse Trypanosomatidae appears |journal=International Journal for Parasitology |volume=31 |issue=5–6 |pages=648–52 |date=May 2001 |doi=10.1016/S0020-7519(01)00139-4|pmid=11334958}} A few genera have life-cycles involving a secondary host, which may be a vertebrate, invertebrate or plant. These include several species that cause major diseases in humans.{{cite journal |vauthors=Simpson AG, Stevens JR, Lukes J |title=The evolution and diversity of kinetoplastid flagellates |journal=Trends in Parasitology |volume=22 |issue=4 |pages=168–74 |date=April 2006 |pmid=16504583 |doi=10.1016/j.pt.2006.02.006 }} Some trypanosomatida are intracellular parasites, with the important exception of Trypanosoma brucei.

Medical importance

The three major human diseases caused by trypanosomatids are; African trypanosomiasis (sleeping sickness, caused by Trypanosoma brucei and transmitted by tsetse flies{{cite web |title=Trypanosomiasis, human African (sleeping sickness) |url=https://www.who.int/en/news-room/fact-sheets/detail/trypanosomiasis-human-african-(sleeping-sickness) |website=www.who.int |access-date=14 May 2020 |language=en |archive-date=20 April 2018 |archive-url=https://web.archive.org/web/20180420223033/http://www.who.int/mediacentre/factsheets/fs259/en/ |url-status=live }}), South American trypanosomiasis (Chagas disease, caused by T. cruzi and transmitted by triatomine bugs), and leishmaniasis (a set of trypanosomal diseases caused by various species of Leishmania transmitted by sandflies

:{{Cite journal|s2cid=233743387|pmid=33950136|doi=10.1590/0001-37652021XXXX|title=Lutzomyia longipalpis: an update on this sand fly vector|last1=Rêgo|first1=Felipe D.|last2=Soares|first2=Rodrigo Pedro|journal=Anais da Academia Brasileira de Ciências|volume=93|issue=3|id=e20200254|year=2021|pages=e20200254 |doi-access=free|hdl=11336/166702|hdl-access=free}}

:

:This review cites this research.

:

:{{Cite journal|last1=Abbasi|first1=Ibrahim|last2=Trancoso Lopo de Queiroz|first2=Artur|last3=Kirstein|first3=Oscar David|last4=Nasereddin|first4=Abdelmajeed|last5=Horwitz|first5=Ben Zion|last6=Hailu|first6=Asrat|last7=Salah|first7=Ikram|last8=Mota|first8=Tiago Feitosa|last9=Fraga|first9=Deborah Bittencourt Mothé|date=2018-11-13|title=Plant-feeding phlebotomine sand flies, vectors of leishmaniasis, prefer Cannabis sativa|journal=Proceedings of the National Academy of Sciences of the United States of America|volume=115|issue=46|s2cid=53112660|pages=11790–11795|doi=10.1073/pnas.1810435115|pmc=6243281|pmid=30373823|bibcode=2018PNAS..11511790A |doi-access=free}}

).

Evolution

The family is known from fossils of the extinct genus Paleoleishmania preserved in Burmese amber dating to the Albian (100 mya) and Dominican amber from the Burdigalian (20–15 mya) of Hispaniola.{{cite journal |last1=Poinar |first1=G. |year=2008 |title=Lutzomyia adiketis sp. n. (Diptera: Phlebotomidae), a vector of Paleoleishmania neotropicum sp. n. (Kinetoplastida: Trypanosomatidae) in Dominican amber |volume=1 |doi=10.1186/1756-3305-1-22 |pmid=18627624 |pmc=2491605 |journal=Parasites & Vectors |pages=22 |issue=1 |doi-access=free }} The genus Trypanosoma is also represented in Dominican amber in the extinct species T. antiquus.{{cite journal |last= Poinar |first=G. |title = Triatoma dominicana sp. n. (Hemiptera: Reduviidae: Triatominae), and Trypanosoma antiquus sp. n. (Stercoraria: Trypanosomatidae), the First Fossil Evidence of a Triatomine-Trypanosomatid Vector Association |journal= Vector-Borne and Zoonotic Diseases |volume= 5|issue= 1|pages= 72–81|year= 2005 |doi=10.1089/vbz.2005.5.72 |pmid=15815152}}

Taxonomy

Three genera are dixenous (two hosts in the life cycle) – Leishmania, Phytomonas and Trypanosoma, while The remainder are monoxenous (one host in the life cycle).{{citation needed|reason=Unsourced statements|date=April 2025}} Paratrypanosoma appears to be the first evolving branch in this order. Fifteen genera are recognised in the Trypanosomatidae and there are three subfamilies – Blechomonadinae, Leishmaniinae and Strigomonadinae.{{clarification needed|reason=Contradicts list which has six subfamilie with many more genera|date=April 2025}} The genera in the subfamily Strigomonadinae are characterised by the presence of obligatory intracellular bacteria of the Kinetoplastibacterium genus.

File:Trypanosoma (248 09) Trypanosoma equiperdum.jpg]]

::* Genus Trypanosoma Gruby 1843

:* Subfamily Blechomonadinae Votypka & Suková 2013

::* Genus Blechomonas Votypka & Suková 2013

File:Leishmania donovani 01.png]]

:* Subfamily Leishmaniinae sensu Maslov & Lukeš 2012

::* Clade Crithidiatae Maslov & Lukeš 2012

File:CRITHIDIA 2.jpg]]

:::* Genus Crithidia Léger 1902

:::* Genus Leptomonas Kent 1880

:::* Genus Lotmaria Schwarz 2015

::* Clade Leishmaniatae Maslov & Lukeš 2012

:::* Genus Borovskyia Kostygov & Yurchenko 2017

:::* Genus Endotrypanum Mesnil & Brimont 1908

:::* Genus Leishmania Ross 1903

:::* Genus Novymonas Votýpka et al. 2015

:::* Genus Paraleishmania Cupolillo et al. 2000

:::* Genus Zelonia Shaw, Camargo et Teixeira 2016

:* Subfamily Phytomonadinae Kostygov & Yurchenko 2015

::* Genus Herpetomonas Kent 1880 non Donovan 1909

::* Genus Lafontella Kostygov & Yurchenko 2015

File:Epifluorescence microscopy of Phytomonas serpens.png]]

::* Genus Phytomonas Donovan 1909

:* Subfamily Strigomonadinae Votypka et al. 2014

File:Angomonas deanei structure.TIF]]

::* Genus Angomonas Souza & Corte-Real 1991

::* Genus Kentomonas Votypka et al. 2014

::* Genus Strigomonas Lwoff & Lwoff 1931

Life cycle

Some trypanosomatids only occupy a single host, while many others are heteroxenous: they live in more than one host species over their life cycle. This heteroxenous life cycle typically includes the intestine of a bloodsucking insect and the blood and/or tissues of a vertebrate. Rarer hosts include other bloodsucking invertebrates, such as leeches,{{cite journal | url=https://www.sciencedirect.com/science/article/abs/pii/S0020751905000020 | doi=10.1016/j.ijpara.2004.12.005 | title=A new lineage of trypanosomes from Australian vertebrates and terrestrial bloodsucking leeches (Haemadipsidae) | journal=International Journal for Parasitology | date=April 2005 | volume=35 | issue=4 | pages=431–443 | last1=Hamilton | first1=P. B. | last2=Stevens | first2=J. R. | last3=Gidley | first3=J. | last4=Holz | first4=P. | last5=Gibson | first5=W. C. | pmid=15777919 }} and other organisms such as plants. Different species go through a range of different morphologies at different stages of the life cycle, with most having at least two different morphologies. Typically the promastigote and epimastigote forms are found in insect hosts, trypomastigote forms in the mammalian bloodstream and amastigotes in intracellular environments. {{cn|date=March 2023}}

Among commonly studied examples, T. brucei, T. congolense, and T. vivax are extracellular, while T. cruzi and Leishmania spp. are intracellular. Trypanosomatids with intracellular stages express {{ Visible anchor |δ-amastin}} proteins on their surfaces. de Paiva et al., 2015 illuminates δ-amastins' roles in intracellular success.

{{ Cite journal

| doi=10.1098/rsob.190036

| pmid=31088251

| pmc=6544988

| title=Tissue tropism in parasitic diseases

| date=2019

| last1=Silva Pereira

| first1=Sara

| last2=Trindade

| first2=Sandra

| last3=De Niz

| first3=Mariana

| last4=Figueiredo

| first4=Luisa M.

| journal=Open Biology

| volume=9

| issue=5

| page=190036

}}

=Sexual reproduction=

Trypanosomatids that cause globally known diseases such leishmaniasis (Leishmania species), African trypanosomiasis referred to as sleeping sickness (Trypanosoma brucei), and Chagas disease (Trypanosoma cruzi) were found to be capable of meiosis and genetic exchange.{{cite journal | doi=10.1590/1678-4685-GMB-2022-0065 | title=Sex in protists: A new perspective on the reproduction mechanisms of trypanosomatids | date=2022 | last1=Silva | first1=Verônica Santana da | last2=Machado | first2=Carlos Renato | journal=Genetics and Molecular Biology | volume=45 | issue=3 | pages=e20220065 | pmid=36218381 | pmc=9552303 }} These findings indicate the capability for sexual reproduction in the Trypanosomatida.

Morphologies

File:TrypanosomatidMorphologies PlainSVG.svg]]

A variety of different morphological forms appear in the life cycles of trypanosomatids, distinguished mainly by the position, length and the cell body attachment of the flagellum. The kinetoplast is found closely associated with the basal body at the base of the flagellum and all species of trypanosomatid have a single nucleus. Most of these morphologies can be found as a life cycle stage in all trypanosomatid genera however certain morphologies are particularly common in a particular genus. The various morphologies were originally named from the genus where the morphology was commonly found, although this terminology is now rarely used because of potential confusion between morphologies and genus. Modern terminology is derived from the Greek; "mastig", meaning whip (referring to the flagellum), and a prefix which indicates the location of the flagellum on the cell. For example, the amastigote (prefix "a-", meaning no flagellum) form is also known as the leishmanial form as all Leishmania have an amastigote life cycle stage.{{cn|date=March 2023}}

  • Amastigote (leishmanial).{{cite journal | title = Developmental Stages of Trypanosomatid Flagellates: a New Terminology | journal = Nature | year = 1966 | last1 = Hoare | volume = 212 | pages = 1385–6 | doi=10.1038/2121385a0 | issue=5068 | first1 = Cecil A. | last2 = Wallace | first2 = Franklin G.| bibcode = 1966Natur.212.1385H | s2cid = 4164112}} Amastigotes are a common morphology during an intracellular lifecycle stage in a mammalian host. All Leishmania have an amastigote stage of the lifecycle. Leishmania amastigotes are particularly small and are among the smallest eukaryotic cells. The flagellum is very short, projecting only slightly beyond the flagellar pocket.
  • {{ Visible anchor |Promastigote}} (leptomonad). The promastigote form is a common morphology in the insect host. The flagellum is found anterior of nucleus emerging directly from the anterior cell body. The kinetoplast is located in front of the nucleus, near the anterior end of the body.
  • {{ Visible anchor |Epimastigote}} (crithidial). Epimastigotes are a common form in the insect host and Crithidia and Blastocrithidia, both parasites of insects, exhibit this form during their life cycles. The flagellum exits the cell anterior of nucleus and is connected to the cell body for part of its length by an undulating membrane. The kinetoplast is located between the nucleus and the anterior end.
  • {{ Visible anchor |Trypomastigote}} (trypanosomal). This stage is characteristic of the genus Trypanosoma in the mammalian host bloodstream as well as infective metacyclic stages in the fly vector. In trypomastigotes the kinetoplast is near the posterior end of the body, and the flagellum lies attached to the cell body for most of its length by an undulating membrane.
  • {{ Visible anchor |Opisthomastigote}} (herpetomonad). A rarer morphology where the flagellum posterior of nucleus, passing through a long groove in the cell.
  • {{ Visible anchor |Endomastigote}}.{{Cite journal |last1=Merzlyak |first1=Ekaterina |last2=Yurchenko |first2=Vyacheslav |last3=Kolesnikov |first3=Alexander A. |last4=Alexandrov |first4=Kirill |last5=Podlipaev |first5=Sergei A. |last6=Maslov |first6=Dmitri A. |date=2001-03-01 |title=Diversity and Phylogeny of Insect Trypanosomatids Based on Small Subunit rRNA Genes: Polyphyly of Leptomonas and Blastocrithidia |journal=The Journal of Eukaryotic Microbiology |language=en |volume=48 |issue=2 |pages=161–169 |doi=10.1111/j.1550-7408.2001.tb00298.x |pmid=12095103 |s2cid=13880469 }} A morphotype where the flagellum does not extend beyond the deep flagellar pocket.

Image:LeishmaniaMexicana Amastigote SEM.jpg|Amastigote: False colour SEM micrograph of amastigote form Leishmania mexicana. The cell body is shown in orange and the flagellum is in red. 219 pixels/μm.

Image:LeishmaniaMexicana Promastigote SEM.jpg|Promastigote: False colour SEM micrograph of promastigote form Leishmania mexicana. The cell body is shown in orange and the flagellum is in red. 119 pixels/μm.

Image:TrypanosomaBrucei_ProcyclicTrypomastigote_SEM.jpg|Trypomastigote: False colour SEM micrograph of procyclic form Trypanosoma brucei. The cell body is shown in orange and the flagellum is in red. 84 pixels/μm.

Other features

Notable characteristics of trypanosomatids are the ability to perform trans-splicing of RNA and possession of glycosomes, where much of their glycolysis is confined to. The acidocalcisome, another organelle, was first identified in trypanosomes.{{cite journal |vauthors=Docampo R, de Souza W, Miranda K, Rohloff P, Moreno SN |title=Acidocalcisomes — conserved from bacteria to man |journal=Nature Reviews Microbiology |volume=3 |issue=3 |pages=251–61 |date=March 2005 |pmid=15738951 |doi=10.1038/nrmicro1097 |s2cid=31935658 }}

= {{Anchor|Kinetoplastibacterium}}Bacterial endosymbiont =

{{Automatic taxobox|name=Kinetoplastibacterium|taxon=Kinetoplastibacterium|authority=Du et al., 1994}}

Six species of trypanosomatids are known to carry an additional proteobacterial endosymbiont, termed TPE (trypanosomatid proteobacterial endosymbionts). These trypansomatids (Strigomonas oncopelti, S. culicis, S. galati, Angomonas desouzai, and A. deanei) are in turn known as SHTs, for symbiont-harboring trypanosomatids. All such symbionts have a shared evolutionary origin and are classified in the Candidatus genus "Kinetoplastibacterium".{{cite journal | last1=Alves |first1=JM |last2=Serrano |first2=MG |last3=Maia da Silva |first3=F |last4=Voegtly |first4=LJ |last5=Matveyev |first5=AV |last6=Teixeira |first6=MM |last7=Camargo |first7=EP |last8=Buck |first8=GA | journal = Genome Biology and Evolution |date=2013 |volume=5 |issue=2 |pages=338–50 |doi=10.1093/gbe/evt012 |doi-access=free |pmid=23345457|pmc=3590767 |title=Genome evolution and phylogenomic analysis of Candidatus Kinetoplastibacterium, the betaproteobacterial endosymbionts of Strigomonas and Angomonas }}

As with many symbionts, the bacteria have a much reduced genome compared to their free-living relatives of genera Taylorella and Achromobacter. (GTDB finds the genus sister to Proftella, a symbiont of Diaphorina citri.){{cite web |title=GTDB - Tree at g__Kinetoplastibacterium |url=https://gtdb.ecogenomic.org/tree?r=g__Kinetoplastibacterium |website=gtdb.ecogenomic.org |access-date=2022-12-20 |archive-date=2022-12-20 |archive-url=https://web.archive.org/web/20221220182712/https://gtdb.ecogenomic.org/tree?r=g__Kinetoplastibacterium |url-status=live }} Reflecting their inability to live alone, they have lost genes dedicated to essential biological functions, relying on the host instead. They have modified their division to become synchronized with the host. In S. culicis at least, the TPE helps the host by synthesizing heme and producing essential enzymes, staying tethered to the kinetoplast.{{Cite journal|last1=de Souza|first1=W.|last2=Motta|first2=M. C.|date=1999|title=Endosymbiosis in protozoa of the Trypanosomatidae family|journal=FEMS Microbiology Letters|volume=173|issue=1|pages=1–8|doi=10.1111/j.1574-6968.1999.tb13477.x|pmid=10220875|doi-access=free}}

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References

{{Reflist}}

{{refbegin}}

  • {{cite journal |vauthors=Bütikofer P, Ruepp S, Boschung M, Roditi I |title='GPEET' procyclin is the major surface protein of procyclic culture forms of Trypanosoma brucei brucei strain 427 |journal= Biochemical Journal|volume=326 |issue=Pt 2 |pages=415–23 |date=September 1997 |pmid=9291113 |pmc=1218686 |doi=10.1042/bj3260415 }}
  • {{cite journal |vauthors=Dean S, Marchetti R, Kirk K, Matthews KR |title=A surface transporter family conveys the trypanosome differentiation signal |journal=Nature |volume=459 |issue=7244 |pages=213–7 |date=May 2009 |pmid=19444208 |pmc=2685892 |doi=10.1038/nature07997 |bibcode=2009Natur.459..213D }}
  • {{cite journal |author=Engstler M, Boshart M |title=Cold shock and regulation of surface protein trafficking convey sensitization to inducers of stage differentiation in Trypanosoma brucei |journal=Genes & Development |volume=18 |issue=22 |pages=2798–811 |date=November 2004 |pmid=15545633 |pmc=528899 |doi=10.1101/gad.323404 |last2=Boshart }}
  • {{cite journal |vauthors=Hofer A, Steverding D, Chabes A, Brun R, Thelander L |title=Trypanosoma brucei CTP synthetase: a target for the treatment of African sleeping sickness |journal=Proceedings of the National Academy of Sciences of the United States of America |volume=98 |issue=11 |pages=6412–6 |date=May 2001 |pmid=11353848 |pmc=33482 |doi=10.1073/pnas.111139498 |bibcode=2001PNAS...98.6412H |doi-access=free }}
  • {{cite book |author1=Janovy, J |author2=Roberts, L.S. |title=Foundations of Parasitology |publisher=McGraw Hill |location=New York NY |year=2005 |pages=61–69 |edition=7th}}
  • {{cite journal |vauthors=Legros D, Ollivier G, Gastellu-Etchegorry M |title=Treatment of human African trypanosomiasis{{emdash}}present situation and needs for research and development |journal=Lancet Infectious Diseases |volume=2 |issue=7 |pages=437–40 |date=July 2002 |pmid=12127356 |doi=10.1016/S1473-3099(02)00321-3 |display-authors=etal |hdl=10144/18268 |hdl-access=free |url=https://fieldresearch.msf.org/bitstream/handle/10144/18268/lancet%20legros%20HAT.pdf?sequence=1&isAllowed=y|url-status=dead|archive-url=https://web.archive.org/web/20211201093335/https://fieldresearch.msf.org/bitstream/handle/10144/18268/lancet%20legros%20HAT.pdf?sequence=1&isAllowed=y|archive-date=2021-12-01}}
  • {{cite journal |author=Matthews KR |title=The developmental cell biology of Trypanosoma brucei |journal=Journal of Cell Science |volume=118 |issue=Pt 2 |pages=283–90 |date=January 2005 |pmid=15654017 |pmc=2686837 |doi=10.1242/jcs.01649 }}
  • {{cite journal |author=Matthews KR, Gull K |title=Evidence for an interplay between cell cycle progression and the initiation of differentiation between life cycle forms of African trypanosomes |journal=Journal of Cell Biology |volume=125 |issue=5 |pages=1147–56 |date=June 1994 |pmid=8195296 | doi = 10.1083/jcb.125.5.1147 |pmc=2120053 |last2=Gull }}
  • {{cite journal |vauthors=Morrison LJ, Marcello L, McCulloch R |title=Antigenic variation in the African trypanosome: molecular mechanisms and phenotypic complexity |journal=Cellular Microbiology |volume=11 |issue=12 |pages=1724–34 |date=December 2009 |pmid=19751359 |doi=10.1111/j.1462-5822.2009.01383.x |s2cid=26552797 |url=http://eprints.gla.ac.uk/8339/1/8339.pdf |access-date=2019-07-10 |archive-date=2021-10-20 |archive-url=https://web.archive.org/web/20211020115950/http://eprints.gla.ac.uk/8339/1/8339.pdf |url-status=live }}
  • {{cite journal |author=Seed JR, Wenck MA |title=Role of the long slender to short stumpy transition in the life cycle of the African trypanosomes |journal=Kinetoplastid Biology and Disease |volume=2 |issue=1 |pages=3 |date=June 2003 |pmid=12844365 |pmc=165594 |doi=10.1186/1475-9292-2-3 |last2=Wenck |doi-access=free }}
  • {{cite journal |author=Shadan S |title=Microbiology: Signals for change |journal=Nature |volume=459 |issue=7244 |pages=175 |date=May 2009 |pmid=19444199 |doi=10.1038/459175a |bibcode=2009Natur.459..175S |doi-access=free }}
  • {{cite journal |author=Sherwin T, Gull K |title=The cell division cycle of Trypanosoma brucei brucei: timing of event markers and cytoskeletal modulations |journal=Philosophical Transactions of the Royal Society B |volume=323 |issue=1218 |pages=573–88 |date=June 1989 |pmid=2568647 |doi=10.1098/rstb.1989.0037|last2=Gull |bibcode=1989RSPTB.323..573S |doi-access= }}
  • {{cite web |title=African trypanosomiasis |date=August 2006 |publisher=World Health Organization |url=https://www.who.int/mediacentre/factsheets/fs259/en/ |access-date=2020-10-05 |archive-date=2016-12-04 |archive-url=https://web.archive.org/web/20161204153318/http://www.who.int/mediacentre/factsheets/fs259/en/ |url-status=live }}
  • {{Cite EB1911|wstitle=Trypanosomes|volume=27|pages=340–347|first=Harold Mellor|last=Woodcock}} ([https://archive.org/details/encyclopaediabri27chisrich/page/340/mode/2up online]). A comprehensive survey of the organisms' natural history.

{{refend}}

External links

{{Commons category|Trypanosomatida}}

  • [https://web.archive.org/web/20090414211811/http://knoesis.wright.edu/internal/wiki/index.php/Trykipedia Trykipedia], Trypanosomatid specific ontologies
  • [http://tolweb.org/Trypanosomatida/98015 Tree of Life: Trypanosomatida]
  • [http://www.boldsystems.org/index.php/Taxbrowser_Taxonpage?taxid=494532 Taxonomy at BOLD Systems]
  • [http://taxonomicon.taxonomy.nl/TaxonName.aspx?id=199492&tree=0.1&syn=1 Taxonomy at Taxonomicon]
  • [https://tree.opentreeoflife.org/taxonomy/browse?id=5257404 Open Tree Taxonomy]
  • [http://zipcodezoo.com/index.php/Trypanosomatida ZipcodeZoo]

{{Excavata}}

{{Taxonbar|from=Q132954}}

Category:Parasitic excavates

Category:Extant Albian first appearances

Category:Euglenozoa orders