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Un plástido de probable origen de algas verdes en parásitos Apicomplexan
S Köhler1, C F Delwiche, P W Denny
1Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
Science (New York, N.Y.)
|March 7, 1997
Resumen
Los parásitos apicomplexa, como el que causa la toxoplasmosis, poseen un orgánulo único que contiene ADN. El análisis filogenético sugiere que este orgánulo se originó a partir de una alga verde a través de la endosimbiosis secundaria.
Área de la Ciencia:
- Parasitología Parasitología.
- Biología Molecular Biología Molecular
- Biología evolutiva Biología evolutiva.
Sus antecedentes:
- Los Apicomplexa son parásitos protozoarios con genomas nucleares y mitocondriales.
- También poseen un ADN extracromosómico circular de 35 kilobases.
Objetivo del estudio:
- Para investigar el origen y la naturaleza del ADN extracromosómico de 35 kilobases en Apicomplexa.
- Para determinar la relación evolutiva de este elemento genético.
Principales métodos:
- La hibridación in situ para localizar el ADN de 35 kilobases dentro de Toxoplasma gondii.
- Análisis filogenético del gen tufA de Apicomplexa y otros organismos.
Principales resultados:
- El ADN de 35 kilobases fue localizado en un orgánulo de cuatro membranas en Toxoplasma gondii.
- El análisis filogenético agrupó este genoma organellar con cianobacterias y plástidos, específicamente agrupándose con plástidos de algas verdes.
Conclusiones:
- Apicomplexa adquirió un plástido a través de la endosimbiosis secundaria.
- El plástido probablemente fue adquirido de una alga verde, lo que indica un evento evolutivo significativo en estos parásitos.
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