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Los fenotipos de pigmentación de los alelos del locus de extensión variante son el resultado de mutaciones puntuales
L S Robbins1, J H Nadeau, K R Johnson
1Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University, Portland 97201.
Cell
|March 26, 1993
Resumen
El locus de extensión en ratones codifica el receptor de la hormona estimulante de melanocitos (MSH), que influye en el color del pelaje. Las mutaciones en este gen conducen a colores amarillos o oscuros de la capa al alterar la función del receptor.
Área de la Ciencia:
- Genética La genética.
- Biología Molecular Biología Molecular
- Determinación del color del pelaje de los mamíferos
Sus antecedentes:
- La variación del color del pelaje en los mamíferos, incluidos caballos, perros, zorros y ratones, a menudo está controlada por alelos en el locus de extensión.
- Los alelos dominantes en el locus de extensión están asociados con colores de capa oscuros, mientras que los alelos recesivos están vinculados a fenotipos más claros o amarillos.
Objetivo del estudio:
- Para identificar el gen codificado por el locus de extensión murina.
- Aclarar los mecanismos moleculares por los cuales diferentes alelos en el locus de extensión afectan el color del pelaje.
Principales métodos:
- Análisis genético de mutaciones del color del pelaje en ratones.
- Caracterización molecular del locus de extensión y su proteína codificada.
- Estudios funcionales de los receptores mutantes de la hormona estimulante de los melanocitos (HSM).
Principales resultados:
- El locus de extensión murina codifica el receptor de la hormona estimulante de melanocitos (MSH).
- Un alelo amarillo recesivo (e) es el resultado de una mutación de cambio de marco, que conduce a un receptor de MSH no funcional.
- Los alelos melanizantes dominantes (Eso, Eso-3J, Etob) causan receptores hiperactivos de MSH debido a mutaciones puntuales, con Eso-3J mostrando activación constitutiva y Etob exhibiendo una mayor respuesta hormonal.
Conclusiones:
- El receptor de MSH es un regulador clave del color del pelaje en ratones.
- Las mutaciones específicas en el gen del receptor de MSH pueden conducir a fenotipos de color de pelaje distintos al alterar la actividad del receptor.
- La comprensión de estos mecanismos genéticos proporciona información sobre la pigmentación de los mamíferos.
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