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Distribución de las transcripciones de ARN de las secuencias estructurales e intermedias del gen de la ovalbumina
Science (New York, N.Y.)
|April 20, 1979
Resumen
Las secuencias de intervención en el gen de la ovalbumina se transcriben pero no se transportan eficientemente al citoplasma. Esto sugiere que estas secuencias juegan un papel más allá de la codificación de proteínas en la regulación génica.
Área de la Ciencia:
- Biología Molecular Biología Molecular
- Regulación de la expresión génica Regulación de la expresión génica
- Estructura del gen eucariota Estructura del gen eucariota
Sus antecedentes:
- El gen de la ovalbúmina en los eucariotas contiene secuencias intermedias (intrones) que se eliminan durante el procesamiento del ARN.
- La función precisa de estas secuencias intermedias y sus transcripciones sigue siendo un área de investigación.
Objetivo del estudio:
- Investigar la función y la localización celular de las transcripciones derivadas de las secuencias intermedias del gen de la ovalbúmina.
- Para comparar la distribución de las transcripciones de secuencias intermedias con las transcripciones maduras de ARN mensajero (ARNm).
Principales métodos:
- Preparación de sondas de ADN etiquetadas radiactivamente específicas para las secuencias intermedias de ovalbumina.
- Aislamiento de ARN de las células del oviducto de pollo (células enteras, núcleos, polisomas).
- Cuantificación de las transcripciones de ARN utilizando ensayos de hibridación con sondas de ADN clonadas.
Principales resultados:
- Las células del oviducto contienen aproximadamente 58.000 moléculas de ARNm de secuencia estructural de la ovalbúmina (ARNmov), predominantemente en el citoplasma.
- Menos de 300 moléculas de ARN por célula se transcriben a partir de secuencias intermedias de ovalbumina.
- Estas transcripciones de secuencias intermedias están casi exclusivamente localizadas dentro del núcleo.
Conclusiones:
- La localización diferencial de las transcripciones de secuencias estructurales e intermedias indica distintas vías de procesamiento.
- Las transcripciones de secuencias intervenidas no se transportan preferentemente a los polisomas citoplasmáticos, lo que sugiere que no funcionan como ARNm maduro.
- Esto implica una función reguladora para las secuencias intermedias o sus transcripciones, separadas de la codificación de proteínas.
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