J Slack

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..There are also one-semester, final-year projects spent in the labs of faculty members, several of whom specialise in developmental biology and offer projects accordingly...

..But recent work shows that muscle satellite cells are also involved in amphibian regeneration and the controversy about the reality of muscle dedifferentiation is heating up again...

..This has been used to introduce various gene products expected to prolong the period of regenerative capacity, but none has so far been successful...

..This article reviews his life and work, and enquires to what extent his ideas are relevant tools for understanding the biological problems of today...

..For example, ectopic expressions of Vestigial can convert Drosophila leg to wing; of C/EBPbeta can convert pancreatic exocrine cells to hepatocytes; and expression of C/EBPalpha and PPARgamma can convert myoblasts to adipocytes...

..The transformation of lung to intestinal tissue has not previously been described, but it is now reported that it can be brought about by prolonged Wnt signaling in late development...

..These can be converted into several differentiated cell types in vitro, including neurons, and might become a source of cells for therapeutic tissue repair...

..They are responsible for normal tissue renewal or for regeneration following damage. Our present knowledge of their properties is limited and is mainly derived from studies of cell kinetics and from clonal analysis...

..The transdifferentiation of hepatic to pancreatic cells represents one possible source of beta-cells for human islet transplantation and this study shows that such a transdifferentiation can be achieved in vitro...

..This mechanism may operate in combination with other changes during fetal programming, leading to type 2 diabetes in later life...

..This shows that metaplasia between differentiated cell types does not occur, and that the process of Xenopus tail regeneration is more akin to tissue renewal in mammals than to urodele tail regeneration...

..The results demonstrate that regenerative capability can be enabled by genetic modifications that reactivate specific components of the developmental program...

..This shows that inhibition of pax7 action does not prevent differentiation of satellite cells to myofibres, but it does prevent their maintenance as a stem cell population...

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..This approach could generate new therapies for many human diseases...

..The results show that the molecular mechanism of Xenopus tadpole tail regeneration is surprisingly similar to that of the Xenopus limb bud and the zebrafish caudal fin, despite the difference of anatomy...

..Prolonged copper deprivation in rats followed by refeeding with a normal diet has previously been used to induce the appearance of hepatocyte-like cells in the pancreas, but the effects on islet size and morphology have not been determined...

..The regeneration of the neural crest derivatives has not previously been examined and is described in this paper...

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..In the endocrine cell clusters we do not find glucagon-expressing cells surrounding insulin-expressing cells, either in the tadpole or in the mature frog pancreas...

..In conclusion, these results suggest that pancreatic hepatocytes produced by this method may offer an alternative model to primary cultures of hepatocytes for the study of liver function...

..We also present evidence for (i) the molecular mechanism which regulates the conversion between pancreas and liver and (ii) the cellular basis of the switch in phenotype...

..The aim of this study was to determine whether a gene overexpression protocol based on Pdx1 would be able to cause conversion of liver to pancreas...

..This review examines recently discovered cases of metaplasia, and speculates on the potential molecular and cellular mechanisms that underlie the switches, and their significance to developmental biology and medicine...

..XHoxd13 is not expressed until relatively late and appears to be involved only in patterning of the blastema...

..These differences may represent properties of the SPU organisation that is characteristic of vertebrate tissues...

..This is achieved using inhibitors of the protease that carries out the ligand-induced intramembranous cleavage of Notch. Other protease inhibitors that do not inhibit Notch cleavage do not affect tail outgrowth...

..Here, we present a strategy and protocols to transdifferentiate developmentally related hepatocytes into beta-cells by the ectopic expression of critical beta-cell transcription factors...

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..The mammalian bile-duct-derived beta cells might therefore represent an extant trace of the evolutionary origin of the vertebrate beta cell...

..The AR42J cell system has been used to elucidate the cell lineage and the molecular basis of transdifferentiation of pancreas to liver...

..Both are complementary to the early expression of Pdx1, a key pancreatic transcription factor. These results are consistent with the idea that C/EBP factors are master regulators for liver development...

..In addition, Cdx2 is sufficient to provoke intestinal metaplasia in the stomach. In the present paper, we review the evidence for the role of Cdx2 in the development of Barrett's metaplasia...

..This suggests that dumb-bell islets are in a state of fission rather than fusion, and that islet fission is a mode of islet production in the postnatal pancreas...

..The results show that, in normal development, the squamous epithelium arises from the columnar epithelium by a direct conversion process...

..Over the next few days, the buds grow as flattened structures which are thin enough to allow the use of wholemount immunostaining methods...

..It may also increase circulating levels of TNFalpha (tumour necrosis factor alpha), which activates Cdx2. In addition, there may be effects of diet on the composition of the bile...

..This work could reopen a consideration of the role of electric fields in regeneration, an issue that has caused much controversy in the past...