Up-regulation of some developmental genes has been observed in cancerous tissues and cancer cells. Sal-like 4 (SALL4), a member of the homologs of Dorosophila spalt (sal) gene, plays a key role in early development and organogenesis. SALL4 encodes a C2H2 multiple zinc finger protein, and is a causative gene for Okihiro/Duane radial ray syndrome, the major symptoms of which are limb malformation...

Identifying the molecular pathways that are required for regeneration remains one of the great challenges of regenerative medicine. Although genetic mutations have been useful for identifying some molecular pathways, small molecule probes of regenerative pathways might offer some advantages, including the ability to disrupt pathway function with precise temporal control. However, a vertebrate r...

During amphibian epimorphic limb regeneration, local injury produces metabolic changes that lead to cellular dedifferentiation and formation of a blastema, but few details of these changes have been elucidated. Here we report the first global proteomic analysis of epimorphic regeneration comparing the profiles of abundant proteins in larval limbs of the anuran Xenopus laevis (stage 53) at the t...

We have analysed DNA synthesis in early phases of regeneration in a marine Polychaete Annelid, Owenia fusiformis. The length and efficiency of the prereplicative phase was found to vary with the diurnal rhythm of activity of the animal; that is, it depends on the initial state of the cell population at the moment of the onset of proliferative stimulatin. When animals were operated on at 12 a.m....

Tadpoles of the bullfrog Rana catesbeiana lose the ability to regenerate limbs amputated through the femur at a very early stage in development. Well-differentiated limbs which in other species can regenerate if amputated through the ankle, cannot in this species. Nonregenerating tadpole limbs either show rapid healing of the cut surface by connective tissue with no breakdown of skeletal struct...

Mammalian digit regeneration progresses through consistent stages: histolysis, inflammation, epidermal closure, blastema formation, and finally redifferentiation. What we do not yet know is how each stage can affect others. Questions of stage timing, tissue interactions, and microenvironmental states are becoming increasingly important as we look toward solutions for whole limb regeneration. Th...

Larval Ambystoma tail regenerates, innervated by the intact spinal cord, were cultured with their epidermal covering in modified Parker's medium (CMRL-1415) and the morphological integrity of the explanted regenerates was maintained with consistent success. The results show that the larval urodele tail blastema is capable of undergoing growth and differentiation when isolated in vitro and regen...

Teleost fishes can regenerate their fins by epimorphic regeneration, a process that involves the transition of the formerly quiescent tissues of the stump to an active, growing state. This involves dynamic modifications of cell phenotype and behavior that must rely on alterations of the cytoskeleton. We have studied the spatial and temporal distribution of three main components of the cytoskele...

In contrast to mammals, some fish and amphibians have retained the ability to regenerate complex body structures or organs, such as the limb, tail, eye lens, or even parts of the heart. One major difference in the response to injury is the appearance of a mesenchymal growth zone or blastema in these regenerative species instead of the scarring seen in mammals. This blastema is thought to largel...

Since the precise interactions of the various newt limb blastema cell types (pleiomorphic, bipolar, signet and multinucleated cells) with one another are difficult to ascertain in vivo, in this study we describe the in vitro behavior and interactions of these cell types with one another. The data show that the mononuclear signet cells interact (fuse) with other signet cells or fuse directly wit...