Ray–Interray Interactions during Fin Regeneration of Danio rerio

Abstract

Teleost fin ray bifurcations are characteristic of each ray in each fin of the fishes. Control of the positioning of such morphological markers is not well understood. We present evidence suggesting that the interray blastema is necessary for a proper bifurcation of each ray during regeneration in Danio rerio (Hamilton-Buchanan) (Cyprinidae, Teleostei). We performed single ray ablations, heterotopical graftings of ray fragments and small holes in lateral rays which do not normally bifurcate, to generate recombinants in which the lateral rays are surrounded with ectopic interrays originating from different positions within the tail fin. These ray-interray recombinants do now bifurcate. Furthermore, we show that the interray tissue and surrounding epidermis can modulate the length of the ray. These results stress the role of the interray in inducing bifurcations of the ray blastema as well as modulating ray morphogenesis in general. In addition, gene expression analysis under these experimental conditions suggests that msxA and msxD expression in the ray and interray epidermis is controlled by the ray blastema and that bmp4 could be a candidate signal involved in these inductions.

Shh promotes direct interactions between epidermal cells and osteoblast progenitors to shape regenerated zebrafish bone

“…This balanced signaling network, however, does not explain how regenerated bones become bifurcated in the same pattern as the lost fin. Earlier studies show that ray branching requires a neighboring ray (Marí-Beffa et al, 1999) and transplantation of a non-branching dorsal (or ventral) ray to a medial position results in branching of the transplant (Murciano et al, 2002). These observations suggest that cell-cell interactions between adjacent tissues are essential for ray morphogenesis.…”

An organizer controls the development of the “sword,” a sexually selected trait in swordtail fish

“…Interactions between fin rays have previously been suggested to regulate regenerative growth in the zebrafish caudal fin, where the shorter medial rays regenerate additional segments if flanked by longer rays of the dorsal or ventral lobe, and finally approximate the length typical for the new position (Murciano et al 2002). Moreover, probably the clearest case of interactions between fin rays has been demonstrated by Turner (1941), who studied the regeneration of gonopodial rays in the Mosquitofish, Gambusia affinis, after extraction of single rays.…”

Desarrollo de la Aleta Caudal del Salmón (Salmo salar)

“…similar a lo que ocurre en pez cebra (Danio rerio Hamilton-Buchanan). Murciano et al (2002Murciano et al ( , 2007 han presentado evidencia que sugiere que el blastema interrayo es necesario para una bifurcación adecuada de cada rayo durante la regeneración. El tejido circundante y la epidermis interrayo pueden modular la longitud del rayo.…”