Instituto de Medicina Molecular, Instituto Gulbenkian Ciência and University of Lisbon, Portugal.
Laboratory of Prof. António Jacinto

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My MSc project had the principal aim of establishing the telomerase enzyme as a key molecule for the zebrafish caudal fin regenerative process. This ribonucleoprotein complex adds repeatedly sequences of specific base pairs to the ends of the chromosomes, the telomeres, maintaining their length and protecting them from cellular replication problems. Due to the need of innumerous cell divisions during caudal fin regeneration, I was prompted to investigate whether telomerase was important for this process to be continuously maintained. To challenge the regenerative system, I established a protocol of continuous knockdown through the repeated delivery of morpholinos, specifically in the caudal fin, depriving the proliferating cells of one of the essential constituents of telomerase, the RNA component. This caused a significant reduction in the size of the affected regenerate. Besides affecting regeneration, the inhibition of this gene also interfered with the regular development of zebrafish embryos – another process that requires high cellular replication within a short time frame. These phenotypes proved to be specific after in vivo observation of telomeric bridges, structures associated to the existence of genomic instability caused by the short telomeres.