Autor(es):
Azevedo, Ana Sofia ; Sousa, Sara ; Jacinto, Antonio ; Saúde, Leonor
Data: 2012
Identificador Persistente: http://hdl.handle.net/10362/23432
Origem: Repositório Institucional da UNL
Projeto/bolsa:
info:eu-repo/grantAgreement/FCT//SFRH%2FBD%2F33179%2F2007/PT;
info:eu-repo/grantAgreement/FCT/3599-PPCDT/PTDC%2FSAU-OBD%2F64628%2F2006/PT;
info:eu-repo/grantAgreement/FCT/3599-PPCDT/PTDC%2FSAU-OBD%2F100202%2F2008/PT;
info:eu-repo/grantAgreement/FCT/3599-PPCDT/PTDC%2FSAU-OBD%2F100200%2F2008/PT;
Assunto(s): PROLIFERATION; LIMB REGENERATION; Bony ray bifurcations; RETINOIC ACID; SONIC HEDGEHOG; BLASTEMA; Fgf; Zebrafish; Shh; Caudal fin regeneration; GROWTH; Caudal fin regeneration; Bony ray bifurcations; Shh, Fgf; Zebrafish
Descrição
We thank Lara Carvalho and Fabio Valerio for excellent zebrafish husbandry, Andreia Pinto for histology and Antonio Temudo for imaging support. We are grateful to C. Certal and S. Pascoal for comments on the manuscript. A. S. A and S. S were supported by FCT fellowships (SFRH/BD/33179/2007 and SFER/BD/32952/2006). L. S. was supported by two FCT grants (PTDC/SAU-OBD/64628/2006 and PTDC/SAU-OBD/100202/2008) and A.J. was supported by one FCT grant (PTDC/SAU-OBD/100200/2008).
Background: Zebrafish has emerged as a powerful model organism to study the process of regeneration. This teleost fish has the ability to regenerate various tissues and organs like the heart, spinal cord, retina and fins. In this study, we took advantage of the existence of an excellent morphological reference in the zebrafish caudal fin, the bony ray bifurcations, as a model to study positional information upon amputation. We investigated the existence of positional information for bifurcation formation by performing repeated amputations at different proximal-distal places along the fin. Results: We show that, while amputations performed at a long distance from the bifurcation do not change its final proximal-distal position in the regenerated fin, consecutive amputations done at 1 segment proximal to the bifurcation (near the bifurcation) induce a positional reset and progressively shift its position distally. Furthermore, we investigated the potential role of Shh and Fgf signalling pathways in the determination of the bifurcation position and observed that they do not seem to be involved in this process. Conclusions: Our results reveal that, an amputation near the bifurcation inhibits the formation of the regenerated bifurcation in the pre-amputation position, inducing a distalization of this structure. This shows that the positional memory for bony ray bifurcations depends on the proximal-distal level of the amputation.
