Identificación y validación funcional de nuevos genes implicados en la regeneración de la aleta y el corazón del pez cebra

• Autores: Álvaro González Rajal
• Directores de la Tesis: José Luis de la Pompa Mínguez (dir. tes.)
• Lectura: En la Universidad Autónoma de Madrid ( España ) en 2012
• Idioma: español
• Tribunal Calificador de la Tesis: Paola Bovolenta Nicolao (presid.), Ramón Muñoz Chápuli (secret.), Nadia Mercader Huber (voc.), Manuel Marí-Beffa (voc.), Ignacio Flores Hernández (voc.)
• Materias:
  • Ciencias de la vida
    • Biología molecular
• Enlaces
  • Tesis en acceso abierto en: digitool-uam.greendata.es
• Resumen

  • Regeneration is a complex biological process by which animals restore the shape, structure, and function of body parts that are lost or damaged. Despite the remarkable ability to regenerate damaged structures that are observed during embryonic and newborn life, only a few vertebrate species retain a significant regenerative capacity during adulthood. Among these species, the zebrafish (Danio rerio) is able to regenerate organs such as the heart and the fins.

    We have analyzed the gene expression profile during regeneration of heart and fin by microarray technology, and we have identified novel genes whose expression is up regulated during these processes. Some of these genes are common to both regenerative processes and others are heart- or fin-specific. Among the first group we found stress-response genes, genes related with extracellular matrix deposition and remodelling and cellular signalling pathway¿s genes. Among the last ones we found signaling molecules such as raldh2, midkine-a and caveolin-1.

    In order to validate our findings we have done in situ hybridization and qPCR analysis. raldh2, midkine-a and caveolin-1 expression is up regulated at 24 hours post amputation (hpa) and remains up regulated until 14 days after amputation (dpa) in hearts and 72 hpa in fins. Moreover, syndecan-2 (a receptor for midkine-a) and PTRF-cavin (caveolin-1 partner gene) have a closely similar pattern of expression to that of midkine-a and caveolin-1 during both heart and fin regeneration. Injection of a morpholino against raldh2, midkine a, syndecan-2, caveolin-1 and PTRF-cavin in 24hpa fins significantly impairs regeneration and proliferation. We have generated transgenic zebrafish lines carrying a dominant negative version of Midkine-a or Syndecan-2 or Caveolin-1 or Wt1 (a gene involved in heart development that could be up-stream of midkine-a during heart regeneration) under the control of an inducible promoter, and we have found that these genes are required for heart regeneration upon cryoinjury. Midkine-a is also required for proper fin regeneration and during heart regeneration is involved along with raldh2 in regulating inflammation response. Raldh2 participes in the regulation of midkine-a¿s expression during heart regeneration and probably during fin regeneration as well.

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