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Los priones son un mecanismo común para la herencia fenotípica en levaduras silvestres
Randal Halfmann1, Daniel F Jarosz, Sandra K Jones
1Whitehead Institute for Biomedical Research, 9 Cambridge Center, Cambridge, Massachusetts 02142, USA.
Nature
|February 17, 2012
Resumen
Los priones de levadura, o proteínas que se modelan a sí mismas, son comunes en las cepas silvestres y confieren diversos rasgos beneficiosos. Estos elementos epigenéticos pueden impulsar la adaptación y la evolución en las poblaciones naturales.
Área de la Ciencia:
- * Biología molecular.
- * La genética.
- * Biología evolutiva.
Sus antecedentes:
- * Los priones de levadura son proteínas de auto-modelado que pueden actuar como elementos epigenéticos, potencialmente impulsando la diversidad y adaptación fenotípica hereditaria.
- * El papel de los priones en las poblaciones naturales y su contribución a la evolución es controvertido, y algunos los ven como artefactos raros de laboratorio.
Objetivo del estudio:
- * Investigar la prevalencia y el significado funcional de los priones de levadura ([PSI(+) y [MOT3(+) ] en cepas silvestres de Saccharomyces.
- * Determinar si estos priones confieren fenotipos beneficiosos bajo condiciones selectivas y contribuyen a la evolución adaptativa.
Principales métodos:
- * Pruebas bioquímicas de aproximadamente 700 cepas de Saccharomyces silvestres para la presencia de priones [PSI(+) ] o [MOT3(+).
- * Cribado genético para identificar elementos priónicos desconocidos en cepas silvestres.
- * Análisis fenotípico de cepas portadoras de priones bajo condiciones selectivas.
Principales resultados:
- * Los priones [PSI(+) ] y [MOT3(+) ] se encontraron en muchas cepas silvestres de Saccharomyces, no solo en cepas de laboratorio.
- * Estos priones conferían fenotipos diversos y frecuentemente beneficiosos, ayudando a la supervivencia bajo presiones selectivas.
- * Un tercio de las cepas silvestres albergaban elementos priones desconocidos, generando también fenotipos diversos y a menudo ventajosos.
- * Los rasgos beneficiosos podrían volverse independientes del prión a través de la re-clasificación meiotica, lo que indica una rápida adaptación.
Conclusiones:
- * Los priones de levadura están muy extendidos en la naturaleza y juegan un papel importante en el control de los rasgos hereditarios.
- * Los priones contribuyen a la diversidad fenotípica y pueden proporcionar ventajas adaptativas, ampliando las oportunidades evolutivas.
- * Los hallazgos desafían la percepción de los priones como enfermedades raras, destacando su importancia en la evolución natural.
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