M A Nieto

..We observe that both genes elicit the same responses in the neural tube. Our results indicate that they can be functionally equivalent, although the embryos show a higher response to the endogenous gene, chick Slug...

..Different family members have also been implicated in the signalling cascade that confers left right identity, as well as in the formation of appendages, neural differentiation, cell division and cell survival...

..As such, the neural crest constitutes an excellent model to study cell migration...

..Furthermore, several early sites of Slu and Sna expression have been swapped in the avian lineage. Our analysis of the Snail family may also shed new light on the origin of the neural crest...

..Moreover, they implicate the Eph receptor family in the patterning and innervation of the developing limb, extending its role in axon pathfinding to the distal periphery...

..We also demonstrate a dorsal to ventral expression gradient for Cek11, an Eck-like receptor, the Eph subclass previously suggested to specify positional information along the temporonasal axis...

..We discuss the implications of the distinct duplication events on the acquisition of new functions...

..This change, which is the transition from epithelial to mesenchymal character, occurs at the formation of mesoderm during gastrulation and on emigration of the neutral crest from the neural tube...

..In the somitic mesoderm, the expression correlates with segmentation and the guidance of both neural crest and motor axons through the sclerotomes...

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..Because these changes do not fit easily into current models, we need to invoke additional mechanisms acting on enhancer elements to distribute expression domains and functions of duplicated genes unequally during evolution...

..In the limb bud, GRK2 transcripts were observed in cells of the progress zone and in the interdigital areas. At later stages, the expression in the heart is compatible with the phenotype observed in the GRK2 deficient mice...

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..Thus, Snail1 is the first cue corrected by RA in the PSM to ensure synchronized bilateral segmentation...

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..In light of this data, we have renamed it SNAIL-like, a new player that must be considered in both physiological and pathological studies of SNAIL function in humans...

..In summary, these cells are refractory to the apoptotic effects of TGF-beta, showing characteristics of liver progenitors and of some hepatocellular carcinoma cells...

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..The existence of these crest subpopulations should be considered when analyzing both wild-type embryos and the phenotype of experimentally manipulated chick embryos. Developmental Dynamics 229:136-139, 2004...

..In addition, we evaluated recent observations that FGF ligands and receptors (including FGFR3) act in concert to organize the whole telencephalon activity, rather than independently patterning different areas...

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..In addition, striking rostrocaudal differences unveil how the regulatory cascades are somehow different but still can lead to the production of bona fide neural crest cells...

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..Significantly, Snail is also activated in patients with renal fibrosis. Thus, Snail expression is suppressed during renal development and it must remain silent in the mature kidney where its aberrant activation leads to fibrosis...

..Significantly, Snail1 is aberrantly upregulated in thanatophoric versus normal cartilages from stillborns. Thus, Snail activity may likely be considered a target for achondroplasia therapies...

..These findings open new avenues for understanding the modulation of the epithelial-to-mesenchymal transition in physiological and pathological situations...

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..Nevertheless, strong expression of Scratch2 is retained in the postnatal cortical subventricular zone, in the inner part of the cerebellar external granular layer, and in the glial cells of the adult vomeronasal nerve...

..From these findings, we propose that Snail genes act primarily as survival factors and inducers of cell movement, rather than as inducers of EMT or cell fate...

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..We further show that all three Snail genes lie in regions of extensive paralogy, revealing their common origin through segmental or chromosomal duplication...

..These aspects of the field were revisited and discussed in a recent meeting organized to honour the retirement of Jim Weston and his contribution to the field...

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..Thus, Snail genes illustrate a paradigm whereby reactivation of crucial embryonic genes in adult tissues provokes the onset of devastating diseases...

..These findings identify a previously undescribed pathway in which a component of the breast tumour microenvironment alters cellular structure in culture and tissue structure in vivo, leading to malignant transformation...