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Efecto de posición en los telómeros de S. cerevisiae: represión reversible de la transcripción de Pol II
D E Gottschling1, O M Aparicio, B L Billington
1Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637.
Cell
|November 16, 1990
Resumen
Los telómeros de la levadura pueden reprimir la expresión de los genes cercanos, un fenómeno conocido como efecto de posición. Este mecanismo de control epigenético afecta la transcripción génica basada en la proximidad de los telómeros.
Área de la Ciencia:
- Genética La genética.
- Biología Molecular Biología Molecular
- La epigenética es la epigenética.
Sus antecedentes:
- * Los cromosomas de Saccharomyces cerevisiae terminan con secuencias teloméricas repetitivas.
- * La regulación de la expresión génica es crucial para la función celular.
Objetivo del estudio:
- * Para investigar el impacto de la proximidad de los telómeros en la transcripción de los genes adyacentes en la levadura.
- * Para determinar si los telómeros ejercen un efecto de posición sobre la expresión génica.
Principales métodos:
- * La colocación de genes de ARN polimerasa II (Pol II) adyacentes a las repeticiones teloméricas en S. cerevisiae.
- * Analizando la expresión génica a través de la observación fenotípica (color de la colonia) y los niveles de ARNm.
- * Utilizando marcadores genéticos como ADE2 y URA3 para el análisis de la expresión.
Principales resultados:
- * Los genes colocados inmediatamente al lado de los telómeros mostraron represión transcripcional reversible.
- * Los genes ADE2 ligados a los telómeros resultaron en colonias rojas con sectores blancos, lo que indica una expresión alterada.
- * Un tracto de repetición telomérico interno sólo reprime la expresión génica al volverse telomérico.
Conclusiones:
- * Los telómeros de la levadura ejercen un efecto dependiente de la posición en la transcripción de los genes cercanos.
- * Esta represión génica mediada por los telómeros está controlada epigenéticamente.
- * La proximidad de los telómeros es un factor clave que influye en los niveles de expresión génica.
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