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Acoel gusanos planos: los metazoos bilaterales más antiguos existentes, no miembros de Platyhelminthes
I Ruiz-Trillo1, M Riutort, D T Littlewood
1Departament de Genètica, Facultat de Biologia, Universitat de Barcelona, Diagonal 645, 08028 Barcelona, Spain.
Science (New York, N.Y.)
|March 19, 1999
Resumen
Los gusanos planos de Acoela no son bilaterales primitivos ni derivados de los coelomatos. Nuevos datos genéticos revelan que representan los primeros Bilateria divergentes, lo que tiene un impacto en los estudios evolutivos.
Área de la Ciencia:
- Biología evolutiva Biología evolutiva.
- La genómica es la genómica.
- Zoología Zoología Zoología.
Sus antecedentes:
- El simple diseño corporal de la Acoela llevó al debate sobre su posición evolutiva.
- Anteriormente se los consideraba bilaterales primitivos o coelomatos altamente derivados.
Objetivo del estudio:
- Para determinar la posición filogenética de la Acoela dentro del reino animal.
- Para aclarar los orígenes evolutivos de los primeros planos corporales bilaterales.
Principales métodos:
- Análisis de secuencias de genes de ADN ribosomal 18S de acoeles y otros metazoos.
- Comparación con los datos existentes sobre el desarrollo embrionario y la estructura del sistema nervioso.
Principales resultados:
- El análisis filogenético indica que Acoela no pertenece a los Platyhelminthes.
- Acoela representa el linaje existente más basal de Bilateria.
Conclusiones:
- Los hallazgos apoyan a Acoela como el primer bilateral divergente.
- Esta reclasificación tiene implicaciones significativas para la comprensión de la evolución de los principales planos corporales de los animales y la explosión cámbrica.
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