# Trypanotolerance

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Trypanotolerance
> Markdown URL: https://mediated.wiki/source/Trypanotolerance.md
> Source: https://en.wikipedia.org/wiki/Trypanotolerance
> Source revision: 1348560285
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

{{short description|Ability to live with parasites}}
A '''trypanotolerant''' organism is one which is [relatively less affected](/source/disease_tolerance) by [trypanosome](/source/trypanosoma) infestation.

== By host ==
{{anchor|Livestock}}
=== In livestock ===
Some [breed](/source/breed)s are known for their trypanotolerance. This is especially important in [Africa](/source/Africa) where a [few particular trypanosomes](/source/Animal_trypanosomiasis) are major economic and agricultural [pest](/source/pest_(organism))s.<ref name="Sustainable" /><ref name="Kim-et-al-2017" /><ref name="FAO" /><ref name="CIRAD" />

==== Trypanotolerant livestock breeds ====
* [N'Dama](/source/N'Dama) cattle<ref name="Kim-et-al-2017" />
* [West African Dwarf goats](/source/West_African_Dwarf_goats){{r|Wilson-1991|page=106}} 
* [West African Dwarf sheep](/source/West_African_Dwarf_sheep) (Djallonké)<ref name="Mawuena-1987" />
* [Cameroon sheep](/source/Cameroon_sheep)

=== Trypanotolerance of the N'Dama Cattle and West African Dwarf Sheep and Goats ===
Certain domestic ruminant breeds in sub-saharan Africa show remarkable resistance to the effects of African [trypanosomiasis](/source/trypanosomiasis): they can tolerate the  [parasites](/source/parasites)'s presence while controlling [parasitaemia](/source/parasitaemia) levels and, most importantly, do not show the severe [anemia](/source/anemia) and production loss that are typical of infection in susceptible breeds.<ref name = "A-Role" />

The trypanotolerance trait is seen in [N'Dama cattle](/source/N'Dama_cattle), and it refers to the N'Dama cattle's ability to survive in areas with high tsetse fly endemicity, where other cattle breeds would frequently contract trypanosomiasis.<ref name="Sustainable" /> In areas or locations of low to moderate tsetse fly challenge, typanotolerant N'Dama cattle show lower numbers of parasites in their blood, develop less severe anemia and have also been shown to be more productive.<ref name="Genetic-Basis" />

An investigation to test the resistance of different small ruminant breeds (West African dwarf sheep and goats) to an artificial infection with ''[T. congolense](/source/Trypanosoma_congolense)'' revealed that native sheep and goats had a higher natural resistance to the illness than [exotic breed](/source/exotic_breed)s, with exotic/indigenous [crossbreeds](/source/crossbreeds) falling somewhere in between.<ref name = "Experimental-Infection" /> Despite persistent parasitaemia, clinical signs in trypanotolerant West African dwarf sheep and goats revealed a milder illness with lower mortality.<ref name = "Experimental-Infection" /> The significance of these trypanotolerant traits is highlighted when choosing breeds of [sheep](/source/sheep) and [goat](/source/goat)s for selection programs. Some literature claims that trypanotolerance in small ruminants (sheep and goats) should be viewed as [resilience](/source/Ecological_resilience) rather than [resistance](/source/Resistance_(ecology)) because it is less apparent than in cattle.<ref name = "Rum" />

Trypanotolerance appears to include both non-immunological and [immunological](/source/immunological) pathways and is most likely multifactorial.<ref name = "Arthropodologie-Generale" /> However, physiological and nutritional factors, concurrent diseases, the presence and absence of tsetse, and inter-current diseases all have an impact on the level of resistance displayed by typanotolerant breeds of cattle, sheep, and goats.<ref name = "A-Role" />

In addition to the above-listed criteria, studies have shown that the effective [dose](/source/Dose_(biochemistry)) of the [trypanosome](/source/Trypanosoma) parasite that these animals acquire following the bite of the tsetse fly is also a consideration. It only takes one fly bite to transmit the infection.<ref name = "Arthropodologie-Generale" /> The quantity of trypanosomes injected into an animal's skin as a result of bites determines how severe the sickness will be; thus, trypanotolerance during natural exposure may be influenced by lower infective dosages.<ref name = "A-Role" /> The finding that some cattle that are highly resistant in the field don't always retain that level of resistance after being artificially infected with a specific dose of the parasite may be supportive of this [hypothesis](/source/hypothesis).<ref>{{Cite journal |last1=Chow |first1=Y. W. |last2=Pietranico |first2=R. |last3=Mukerji |first3=A. |date=1975-10-27 |title=Studies of oxygen binding energy to hemoglobin molecule |journal=Biochemical and Biophysical Research Communications |volume=66 |issue=4 |pages=1424–1431 |doi=10.1016/0006-291x(75)90518-5 |issn=0006-291X |pmid=6}}</ref>

==== History of genetic research ====
Trypanotolerance had previously been achieved through normal livestock breeding in cattle, but genetic analysis was becoming a serious option in the 1980s. The effort that would eventually bear fruit began with a conversation between Peter Brumby - then at the [International Livestock Centre for Africa](/source/International_Livestock_Research_Institute) - and [Morris Soller](/source/Morris_Soller) in 1985. This was followed by the opening of the short-lived International Trypanotolerance Center in [the Gambia](/source/the_Gambia) in 1987 with a seminar on the genome mapping project that would continue beyond the Center itself. The project was then actually completed by the ILRI - the successor to the ILCA - in 2003.<ref name="Soller-2015" />

== References ==
<references>

<ref name="Sustainable">{{ Cite journal | year=1998 | issue=1 | volume=17 | first4=M. | first3=N. | first2=E. | first1=G. | last4=Murray | last3=Wissocq | last2=Authie | last1=d'Ieteren | pages=154–175 | journal=[Revue Scientifique et Technique de l'OIE](/source/Revue_Scientifique_et_Technique_de_l'OIE) | issn=0253-1933 | publisher=O.I.E ([World Organisation for Animal Health](/source/World_Organisation_for_Animal_Health)) | doi=10.20506/rst.17.1.1088 | s2cid=1188831 | pmid=9638808 | title=Trypanotolerance, an option for sustainable livestock production in areas at risk from trypanosomosis| doi-access=free | hdl=10568/29592 | hdl-access=free }}</ref>

<ref name="Kim-et-al-2017">{{cite journal | last1=Kim | first1=Soo-Jin | last2=Ka | first2=Sojeong | last3=Ha | first3=Jung-Woo | last4=Kim | first4=Jaemin | last5=Yoo | first5=DongAhn | last6=Kim | first6=Kwondo | last7=Lee | first7=Hak-Kyo | last8=Lim | first8=Dajeong | last9=Cho | first9=Seoae | last10=Hanotte | first10=Olivier | last11=Mwai | first11=Okeyo Ally | last12=Dessie | first12=Tadelle | last13=Kemp | first13=Stephen | last14=Oh | first14=Sung Jong | last15=Kim | first15=Heebal | title=Cattle genome-wide analysis reveals genetic signatures in trypanotolerant N'Dama | journal=[BMC Genomics](/source/BMC_Genomics) | publisher=[BioMed Central](/source/BioMed_Central) | volume=18 | issue=1 | date=2017-05-12 | issn=1471-2164 | doi=10.1186/s12864-017-3742-2 | page=371| pmid=28499406 | pmc=5427609 | doi-access=free }}</ref>

<ref name="FAO">{{cite web | title=Trypanotolerant livestock in the context of trypanosomiasis intervention strategies | website=[Food and Agriculture Organization](/source/Food_and_Agriculture_Organization) of the [United Nations](/source/United_Nations) | url=http://www.fao.org/3/y5832e/y5832e05.htm | access-date=2021-02-20}}</ref>

<ref name="CIRAD">{{cite web | title=Trypanotolerance in West African cattle | website=CIRAD ([Centre de coopération internationale en recherche agronomique pour le développement](/source/Centre_de_coop%C3%A9ration_internationale_en_recherche_agronomique_pour_le_d%C3%A9veloppement)) | url=http://www.cirad.fr/en/our-research/research-results/2011/trypanotolerance-in-west-african-cattle | access-date=2021-02-20}}</ref>

<ref name="Soller-2015">{{cite journal | last=Soller | first=Morris | title=If a Bull Were a Cow, How Much Milk Would He Give? | journal=[Annual Review of Animal Biosciences](/source/Annual_Review_of_Animal_Biosciences) | publisher=[Annual Reviews](/source/Annual_Reviews_(publisher)) | volume=3 | issue=1 | date=2015-02-16 | issn=2165-8102 | doi=10.1146/annurev-animal-022114-110751 | pages=1–17 | pmid=25493539 | s2cid=46733451 | author-link = Morris Soller | doi-access=free }}</ref>

<ref name="Wilson-1991">{{cite book | author=R. T. Wilson | date=1991 | url=https://books.google.com/books?id=VKCtxBeL5ScC&pg=PA106 | title=Small Ruminant Production and the Small Ruminant Genetic Resource in Tropical Africa | location = [Rome](/source/Rome) | publisher = United Nations [Food and Agriculture Organization](/source/Food_and_Agriculture_Organization) | isbn=9789251029985}}</ref>

<ref name="Mawuena-1987">{{cite journal | date=1987 | journal=[Revue d'élevage et de médecine vétérinaire des pays tropicaux](/source/Revue_d'%C3%A9levage_et_de_m%C3%A9decine_v%C3%A9t%C3%A9rinaire_des_pays_tropicaux) | doi=10.19182/REMVT.8696 | s2cid=86116225 | pmid=3444966 | last1=Mawuena | first1=K. | trans-title=High degree of tolerance to trypanosomiasis of dwarf Djallonké sheep and goats in the southern guinean area of Togo. Comparison with trypanosoma tolerant cattle |title=Haut degré de tolérance à la trypanosomose des moutons et des chèvres de race naine Djallonké des régions Sud-guinéennes du Togo. Comparaison avec les bovins trypanotolérants | volume=40 | issue=1 | pages=55–58 |url=https://revues.cirad.fr/index.php/REMVT/article/view/8696 | doi-access=free }}</ref>

<ref name = "A-Role">{{ Cite journal | language = en | year = 1994 | last = Authié | first = E. | issn = 0169-4758 | journal = [Parasitology Today](/source/Parasitology_Today) | volume = 10 | issue = 9 | pages = 360–364 | s2cid = 42585897 | doi = 10.1016/0169-4758(94)90252-6 | title = Trypanosomiasis and trypanotolerance in cattle: A role for congopain?| pmid = 15275419 }}</ref>

<ref name="Genetic-Basis">{{ Cite journal | year=1998 | publisher=[Elsevier](/source/Elsevier) | issue=11 | volume=14 | first2=A. | first1=S. | last2=Teale | last1=Kemp | pages=450–454 | journal=[Parasitology Today](/source/Parasitology_Today) | issn=0169-4758 | doi=10.1016/s0169-4758(98)01334-9 | s2cid=3253779 | pmid=17040846 | title=Genetic Basis of Trypanotolerance in Cattle and Mice}}</ref>

<ref name = "Experimental-Infection">
 {{ Unbulleted list citebundle
    |This review...
    |{{*}} {{ Cite journal | year = 1990 | last1 = Murray | first1 = M. | last2 = Trail | first2 = J. | last3 = d'Ieteren | first3 = G. | title = Trypanotolerance in cattle and prospects for the control of trypanosomiasis by selective breeding | journal = [Revue Scientifique et Technique de l'OIE](/source/Revue_Scientifique_et_Technique_de_l'OIE) | publisher = O.I.E ([World Organisation for Animal Health](/source/World_Organisation_for_Animal_Health)) | volume = 9 | issue = 2 | issn = 0253-1933 | doi = 10.20506/rst.9.2.506 | pages = 369–386 | s2cid = 2846382 | pmid = 2132686| hdl = 10568/33164 | hdl-access = free }}
    |...and this chapter...
    |{{*}} {{ Cite book | year = 1982 | publisher = [Elsevier](/source/Elsevier) | first3 = D. | first2 = W. | first1 = Max | volume = 21 | last3 = Whitelaw | last2 = Morrison | last1 = Murray | pages = 1–68 | series = [Advances in Parasitology](/source/Advances_in_Parasitology) | issn = 0065-308X | title = Host Susceptibility to African Trypanosomiasis: Trypanotolerance | isbn = 978-0-12-031721-9 | s2cid = 38907545 | doi = 10.1016/s0065-308x(08)60274-2 | pmid = 6762064}}
    |...cite this study:
    |{{*}} {{ Cite journal | language = en | issue = 2 | volume = 5 | first2 = E. | first1 = L. | year = 1979 | last2 = Allonby | last1 = Griffin | pages = 97–105 | title = Trypanotolerance in breeds of sheep and goats with an experimental infection of ''Trypanosoma congolense'' | journal = [Veterinary Parasitology](/source/Veterinary_Parasitology) | issn = 0304-4017 | s2cid = 83754228 | doi = 10.1016/0304-4017(79)90001-3 }}
 }}
</ref>

<ref name = "Rum" >{{ Cite journal | date = 2009| language = en | issue = 3 | volume = 25 | publisher = [Cell Press](/source/Cell_Press) | pages = 132–138 | last1 = Geerts | first1 = Stanny | last2 = Osaer | first2 = Sabine | last3 = Goossens | first3 = Bart | last4 = Faye | first4 = Déthié | journal = [Trends in Parasitology](/source/Trends_in_Parasitology) | title = Trypanotolerance in small ruminants of sub-Saharan Africa | doi = 10.1016/j.pt.2008.12.004| pmid = 19200783 }}</ref>

<ref name = "Arthropodologie-Generale">{{ Cite book | date = 2017 | pages = 19–35 | publisher = [IRD Éditions](/source/IRD_%C3%89ditions) | last = Duvallet | first = Gérard | chapter = Chapitre 1. Arthropodologie générale | doi = 10.4000/books.irdeditions.21962 | title = Entomologie médicale et vétérinaire | isbn = 9782709923767 | trans-title = Medical and Veterinary Entomology }}</ref>

</references>

Category:Trypanosomatida
Category:Livestock

---
Adapted from the Wikipedia article [Trypanotolerance](https://en.wikipedia.org/wiki/Trypanotolerance) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Trypanotolerance?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.