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Las mutaciones en el ciclo circadiano impulsan la plasticidad adaptativa en las cianobacterias
Alfonso Mendaña1, María Santos-Merino1, Raquel Gutiérrez-Lanza1
1Instituto de Biomedicina y Biotecnología de Cantabria, Universidad de Cantabria-Consejo Superior de Investigaciones Científicas, Santander, Cantabria 39011, Spain.
Resumen
Las cianobacterias se adaptaron a las duras condiciones alterando su reloj circadiano, impulsando significativamente el crecimiento. Sin embargo, esta adaptación redujo la flexibilidad a los cambios ambientales, destacando una compensación.
Área de la Ciencia:
- Microbiología
- Biología molecular
- Biología evolutiva
Sus antecedentes:
- Los relojes circadianos permiten a los organismos anticiparse a los cambios ambientales.
- El papel de los relojes circadianos en la adaptación a diversos entornos no se entiende completamente.
Objetivo del estudio:
- Investigar cómo las mutaciones del reloj circadiano impulsan la adaptación en cianobacterias bajo presiones ambientales específicas.
- Comprender los mecanismos moleculares que subyacen a la adaptación y su impacto en la flexibilidad ambiental.
Principales métodos:
- Experimento de evolución a largo plazo con *Synechococcus elongatus* PCC 7942 bajo alta luz, alta temperatura y CO2 elevado.
- Secuenciación de todo el genoma para identificar mutaciones en cepas evolucionadas.
- Análisis fenotípico y perfil metabólico para evaluar el crecimiento y los cambios celulares.
Principales resultados:
- Una cepa evolucionada mostró un aumento del 600% en la tasa de crecimiento después de 1.200 generaciones.
- Se identificaron mutaciones clave en *aroK* (que conducen a la sobreexpresión) y *sasA* (que alteran el ritmo circadiano).
- La adaptación dio lugar a cambios metabólicos significativos, incluidos los cambios en el ciclo de Calvin-Benson-Bassham y el metabolismo del glucógeno.
Conclusiones:
- Las mutaciones en los genes de control circadiano pueden impulsar rápidamente la adaptación al alterar el metabolismo central.
- La adaptación confirió una mayor adecuación en condiciones específicas, pero redujo la flexibilidad ambiental, lo que indica una compensación.
- Dirigirse al ciclo circadiano ofrece potencial para la ingeniería de cianobacterias para mejorar la fijación de carbono y la producción de biomasa.
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