Anthony L Mescher

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Complete regeneration of complex tissues and organs is usually precluded by fibrotic reactions that lead to scarring. Fish, salamanders, and larval anurans are among the few vertebrates capable of regenerating lost appendages, and this process seems to recapitulate ontogenic development of the structure in most respects. Recent work has revealed a capacity(More)
Formation of a regeneration blastema on the amputated urodele limb involves changes in the gene activity of differentiated cells resulting in their histological dedifferentiation and their return to a proliferative state. This review summarizes studies in limb regeneration and in the related fields of tissue repair and limb development that provide new(More)
A central feature of epimorphic regeneration during amphibian limb regeneration is cellular dedifferentiation. Two questions are discussed. First, what is the origin and nature of the soluble factors involved in triggering local cellular and tissue dedifferentiation? Secondly, what role does the key stem cell transcription factor Sall4 play in reprogramming(More)
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(More)
Cell proliferation during the early phase of growth in regenerating amphibian limbs requires a permissive influence of nerves. Based on analyses of proliferative activity in denervated blastemas, it was proposed that nerves provide factors important for cells to complete the proliferative cycle rather than for mitogenesis itself. One such factor, the(More)
The myogenic regulatory factors (MRFs) MyoD and Myf5 are the earliest described muscle-specific genes to be expressed in Xenopus development. To study the in vivo effects of overexpressing Xenopus MyoD and Myf5, synthetic RNAs were microinjected into single blastomeres of 2- to 32-cell stage Xenopus embryos. In vivo overexpression of these MRFs initiates(More)
We review key aspects of what is known about limb regeneration in urodele and anuran amphibians, with a focus on the early events of the process that lead to formation of the regeneration blastema. This includes the role of the nerves and wound epithelium, but also covers the inflammatory effects of the amputation trauma and their importance for(More)
Xenopus laevis tadpoles are capable of limb regeneration after amputation, in a process that initially involves the formation of a blastema. However, Xenopus has full regenerative capacity only through premetamorphic stages. We have used the Affymetrix Xenopus laevis Genome Genechip microarray to perform a large-scale screen of gene expression in the(More)
The ability of vertebrates to regenerate amputated appendages is increasingly well-understood at the cellular level. Cells mediating an innate immune response and inflammation in the injured tissues are a prominent feature of the limb prior to formation of a regeneration blastema, with macrophage activity necessary for blastema growth and successful(More)
The influence of the wound epithelium on the cellular events preceding blastema formation was examined by comparing dedifferentiation, DNA labeling indices, and mitotic indices of the distal mesodermal tissues in control regenerating newt forelimbs and in amputated forelimbs covered with a flap of full thickness skin. Three kinds of results were seen(More)