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Robustez fenotípica conferida por potenciadores transcripcionales aparentemente redundantes
Nicolás Frankel1, Gregory K Davis, Diego Vargas
1Howard Hughes Medical Institute and Department of Ecology and Evolutionary Biology, Princeton University, Princeton, New Jersey 08544, USA.
Nature
|June 1, 2010
Resumen
Los potenciadores secundarios en el desarrollo de Drosophila aseguran la formación de rasgos robustos. Su ausencia causa defectos bajo estrés ambiental y variación genética, destacando su papel crucial en la estabilidad fenotípica.
Área de la Ciencia:
- Biología del desarrollo Biología del desarrollo.
- Genética La genética.
- Biología Molecular Biología Molecular
Sus antecedentes:
- Los genes utilizan regiones cis-reguladoras, incluidos los potenciadores transcripcionales, para la regulación génica.
- Los genes del desarrollo a menudo tienen múltiples módulos potenciadores (primarios y secundarios) que impulsan patrones de expresión similares.
- Se supone que los potenciadores secundarios confieren robustez fenotípica contra los cambios ambientales y genéticos.
Objetivo del estudio:
- Investigar el papel de los potenciadores secundarios en la concesión de la robustez fenotípica.
- Para probar la hipótesis de que la actividad redundante del potenciador asegura la estabilidad del rasgo.
Principales métodos:
- Generó un mutante de deficiencia que carece de dos potenciadores secundarios del gen shavenbaby (svb) en Drosophila.
- Se evaluaron los defectos de patrón del tricoma bajo condiciones óptimas de desarrollo embrionario a baja y alta temperatura.
- Analizó el impacto de la eliminación del potenciador secundario en el patrón del tricoma en el contexto de la dosis reducida de genes sin alas.
Principales resultados:
- La ausencia de potenciadores secundarios causó defectos menores a temperaturas óptimas, pero una pérdida significativa de tricomas a temperaturas extremas.
- Los defectos dependientes de la temperatura fueron rescatados por un transgene que expresa el ADNc svb impulsado por un potenciador secundario.
- La pérdida de potenciadores secundarios exacerbó los defectos de tricomas en moscas con un número reducido de copias de genes sin alas.
Conclusiones:
- Los potenciadores secundarios son críticos para mantener la robustez fenotípica, particularmente bajo estrés ambiental.
- Estos potenciadores juegan un papel importante en el amortiguamiento contra la variación genética, asegurando el desarrollo de rasgos consistentes.
- Los hallazgos apoyan la hipótesis de que múltiples potenciadores contribuyen a la estabilidad del desarrollo.
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