Tetrahymena thermophila

Tetrahymena thermophila
Tetrahymena thermophila
	Tetrahymena thermophila
Videnskabelig klassifikation
Domæne	Eukaryoter
(urangeret)	SAR
(urangeret)	Alveolata
Række	Ciliater
Klasse	Oligohymenophorea
Orden	Hymenostomatida
Familie	Tetrahymenidae
Slægt	Tetrahymena
Art	T. thermophila
Videnskabeligt artsnavn
	Tetrahymena thermophila
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Tetrahymena thermophila er frit-levende mikrober som er en ciliat protozo, som også kan skifte mellem levemåderne kommensal og patogen. Tetrahymena thermophila er almindelig i ferskvandsdamme og er 30-60 mikrometer stor.

En modelorganisme i eksperimentalbiologi

Som en ciliat protozo udviser Tetrahymena thermophila kernedimorfisme: To typer af cellekerner. Tetrahymena thermophila har samtidigt en større somatisk makrokerne og en mindre kimbane mikrokerne (til sex) i hver celle og kernerne udfører forskellige funktioner med distinkte cytologiske og biologiske egenskaber. Denne unikke alsidighed tillader videnskabsfolk til at anvende Tetrahymena thermophila til at identificere adskillige vigtige faktorer vedrørende genekspression og genomintegritet. Herudover har Tetrahymena thermophila hundreder af cilier og har komplicerede mikrotubulistrukturer, hvilken gør Tetrahymena thermophila til den optimale model til at illustrere diversitet og mikrotubulisystems funktioner.

Tetrahymena thermophila eksisterer i syv forskellige køn, som kan reproducere i 21 forskellige kombinationer - og en enkelt Tetrahymena thermophila kan ikke reproducere sig seksuelt med sig selv. Hvert individ "beslutter" hvilket køn den vil blive under parring via en stokastisk proces.^[1]^[2]^[3]

Kilder/referencer

^ Selecting; Segment Joining, Gene; Deletion; Cervantes, MD; Hamilton, EP; Xiong, J; Lawson, MJ; Yuan, D; et al. (2013). "Selecting One of Several Mating Types through Gene Segment Joining and Deletion in Tetrahymena thermophila". PLoS Biol. 11 (3): e1001518. doi:10.1371/journal.pbio.1001518.
^ 27 March 2013, nature.com: How a microbe chooses among seven sexes Citat: "...Biologists have uncovered the genetic mechanisms by which an unusual microbe assumes one of seven possible sexes...It was known that “the mating type of the parents has no influence on what the mating type of the progeny is going to be,”..."
^ 2 March 2011, newscientist.com: Zoologger: The hairy beast with seven fuzzy sexes Citat: ".... It has not two but seven sexes, and each one can mate with any of the others...As if that weren’t enough, sex itself is different for this animal. Most cells have a single nucleus that contains all their DNA, but Tetrahymena has two: a large macronucleus and a small micronucleus. The macronucleus controls the everyday functions of the cell, while the micronucleus deals with its complicated sex life..."

Yderligere læsning

Methods in Cell Biology Volume 62: Tetrahymena thermophila, Edited by David J. Asai and James D. Forney. (2000). By Academic Press ISBN 0-12-544164-9
Collins, K.; Gorovsky, M.A. (2005). "Tetrahymena thermophila 5004392". Curr Biol. 15: R317-8. doi:10.1016/j.cub.2005.04.039. (Webside ikke længere tilgængelig)
Eisen, JA; Coyne, RS; Wu, M; Wu, D; Thiagarajan, M; et al. (2006). "Macronuclear Genome Sequence of the Ciliate Tetrahymena thermophila, a Model Eukaryote". PLoS Biol. 4 (9): e286. doi:10.1371/journal.pbio.0040286. PMC 1557398. PMID 16933976.

Eksterne henvisninger

[PLOS2013-1] Selecting; Segment Joining, Gene; Deletion; Cervantes, MD; Hamilton, EP; Xiong, J; Lawson, MJ; Yuan, D; et al. (2013). "Selecting One of Several Mating Types through Gene Segment Joining and Deletion in Tetrahymena thermophila". PLoS Biol. 11 (3): e1001518. doi:10.1371/journal.pbio.1001518.

[2] 27 March 2013, nature.com: How a microbe chooses among seven sexes Citat: "...Biologists have uncovered the genetic mechanisms by which an unusual microbe assumes one of seven possible sexes...It was known that “the mating type of the parents has no influence on what the mating type of the progeny is going to be,”..."

[3] 2 March 2011, newscientist.com: Zoologger: The hairy beast with seven fuzzy sexes Citat: ".... It has not two but seven sexes, and each one can mate with any of the others...As if that weren’t enough, sex itself is different for this animal. Most cells have a single nucleus that contains all their DNA, but Tetrahymena has two: a large macronucleus and a small micronucleus. The macronucleus controls the everyday functions of the cell, while the micronucleus deals with its complicated sex life..."

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