Incorporation of bromodeoxyuridine in regenerating fin tissue of the goldfish Carassius auratus

Abstract

We have investigated the pattern of incorporation of 5-bromo-2'-deoxyuridine-5'-monophosphate (BrdU) by proliferating cells during regeneration of the tail fin of Carassius auratus. Fifteen days after amputation, intraperitoneal injection of a single dose of 0.25 mg/g wet weight of BrdU and subsequent immunocytochemical detection on sections revealed groups of replicating cells in the blastema and epidermis at different proximodistal levels. Proliferating blastemal cells were confined to a crowded, compact distal area that lost its replicative capacity laterally, causing the differentiation of scleroblasts, which synthesize the lepidotrichia hemisegments. Proximally, but centrally located, the blastemal cells did not incorporate BrdU and they differentiated giving rise to the mature intraray connective tissue. An independent cell-proliferation process was noted in the epidermis. The distal cap did not proliferate; the lateral faces of the epidermis showed high rates of cell replication in the central layer at every level of the regenerate rays; quiescent cells remained in the superficial layers. The basal epidermal cells did not incorporate BrdU when actinotrichia were present. The possible role of basal epidermal cells in the synthesis of actinotrichia, the contribution of these collagen macrofibrils to the morphogenetic process, and the different pathways of cell differentiation during fin regeneration are discussed.

Pattern of bromodeoxyuridine incorporation in the advanced stages of arm regeneration in the feather star Antedon mediterranea

“…However, recent investigations have demonstrated that it is possible to avoid these problems and successfully employ the BrdU methods by resorting to suitable short-term administrations (Oinuma et al 1992;Santamaría et al 1996). Our present and past results are consistent with these data and complete the view as far as the diverse possible applications of this method are concerned.…”

A dual epimorphic and compensatory mode of heart regeneration in zebrafish

“…This myosin isoform may permit the modification of the sarcomere structure providing a higher cellular plasticity that is needed for proliferation, migration and morphogenesis (Maggs et al, 2000). It is interesting to note that the cluster of embCMHC-expressing cells was confined to the distance of 100 μm from the injury site, which corresponds to the similar spatial domain that was reported for mesenchymal dedifferentiation during epimorphic fin regeneration (Akimenko et al, 2003;Poss et al, 2003;Santamaria et al, 1996). This correlation strongly suggests the existence of similar mechanisms and factors in both the fin and the heart, which spread from the injury site to promote cellular dedifferentiation of the abutting stump tissues.…”

Posterior hoxa genes expression during zebrafish bony fin ray development and regeneration suggests their involvement in scleroblast differentiation

“…1A, B). On the basis of their position, these cells could be identified as differentiating dermal bone-forming cells or scleroblasts (Santamaria et al 1996). Histological sections along the proximodistal axis of the ray and cross sections showed that hoxa11b-and hoxa13bexpressing cells were mesenchymal and located between actinotrichia and the basal layer of the epidermis (Fig.…”