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Evolución de la determinación del sexo y del cromosoma Y: secuencias relacionadas con el SRY en marsupiales
J W Foster1, F E Brennan, G K Hampikian
1Department of Genetics and Human Variation, La Trobe University, Bundoora, Victoria, Australia.
Nature
|October 8, 1992
Resumen
Los científicos identificaron homólogos del gen SRY en los cromosomas Y de dos especies de marsupiales. Estos hallazgos revelan la rápida evolución de los genes SRY fuera de la caja HMG, ofreciendo información sobre la determinación del sexo de los mamíferos.
Área de la Ciencia:
- Genética La genética.
- Biología evolutiva Biología evolutiva.
- Reproducción de los mamíferos La reproducción de los mamíferos.
Sus antecedentes:
- La determinación del sexo de los mamíferos está controlada principalmente por el factor determinante del testículo transmitido por el cromosoma Y.
- El gen SRY (Región Y de Determinación del Sexo), identificado en el cromosoma Y humano, se considera el principal factor determinante del testículo en humanos y ratones.
Objetivo del estudio:
- Identificar y clonar genes relacionados con SRY de los cromosomas Y de dos especies de marsupiales.
- Para comparar secuencias de SRY ubicadas en Y de euteros (placentarios) y metateros (marsupiales) para comprender sus patrones evolutivos.
Principales métodos:
- Utilizó una sonda genética SRY humana para identificar y clonar genes homólogos.
- Centrado en los cromosomas Y de dos especies distintas de marsupiales.
- Se realizaron comparaciones de secuencias entre genes SRY euteros y metateros.
Principales resultados:
- Identificó y clonó con éxito homólogos de SRY de los cromosomas Y de las especies de marsupiales estudiadas.
- Las comparaciones de secuencias indicaron rápidos cambios evolutivos en los genes SRY, particularmente en regiones fuera de la caja HMG de unión al ADN.
- Los homólogos SRY, junto con los homólogos Ube1y, representan los primeros genes identificados en el cromosoma Y del marsupial.
Conclusiones:
- El estudio proporciona la primera identificación de genes del cromosoma Y en marsupiales, específicamente homólogos de SRY.
- La evidencia sugiere una evolución acelerada de los genes SRY a través de linajes de mamíferos, especialmente en dominios de caja no HMG.
- Estos hallazgos contribuyen a comprender los mecanismos moleculares y la dinámica evolutiva de la determinación del sexo de los mamíferos.
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