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Control genético primario de la diferenciación sexual somática en un mamífero
W S O1, R V Short, M B Renfree
1Department of Anatomy, Monash University, Melbourne, Victoria, Australia.
Nature
|February 25, 1988
Resumen
La diferenciación sexual de los mamíferos puede implicar efectos genéticos que preceden a las hormonas testiculares. Nuevos hallazgos en marsupiales revelan dimorfismos sexuales antes del desarrollo de las gónadas, desafiando el modelo hormonal clásico.
Área de la Ciencia:
- Biología del desarrollo Biología del desarrollo.
- Genética La genética.
- Biología Reproductiva Biología Reproductiva.
Sus antecedentes:
- El modelo clásico de diferenciación sexual de los mamíferos postula que un gen del cromosoma Y inicia el desarrollo testicular.
- Las hormonas testiculares (andrógenos y sustancias inhibidoras de Mullerian) se consideran los principales impulsores del desarrollo del tracto reproductivo masculino y femenino, respectivamente.
- Se cree que esta mediación hormonal es una consecuencia de la determinación genética inicial del sexo gonadal.
Objetivo del estudio:
- Investigar el momento y los mecanismos de diferenciación sexual en los mamíferos.
- Desafiar el énfasis excesivo en las hormonas testiculares en los modelos clásicos de diferenciación sexual.
- Para explorar posibles influencias genéticas anteriores en el dimorfismo sexual.
Principales métodos:
- Análisis comparativo de la diferenciación sexual en un mamífero marsupial.
- Observación de cambios morfológicos y genéticos durante el desarrollo temprano.
- Examen de la diferenciación gonadal y los dimorfismos sexuales.
Principales resultados:
- Evidencia de extensos dimorfismos sexuales en marsupiales que preceden a la diferenciación morfológica gonadal.
- Sugiere que los factores genéticos pueden desempeñar un papel en la diferenciación sexual independientemente de la secreción temprana de hormonas testiculares.
- Desafía la noción de que toda diferenciación sexual es únicamente una consecuencia de la determinación inicial del sexo gonadal.
Conclusiones:
- La visión clásica de la diferenciación sexual de los mamíferos puede haber exagerado el papel de las hormonas testiculares.
- Es probable que los efectos genéticos anteriores, independientemente de la diferenciación gonadal, contribuyan significativamente al dimorfismo sexual.
- Se necesita más investigación para dilucidar completamente la compleja interacción de factores genéticos y hormonales en el desarrollo sexual de los mamíferos.
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