... in melanocyte and ENS development, highlighting species-specific differences. Box 2. Isolated and syndromic Hirschsprung disease and the EDN3-EDNRB pathway Hirschsprung disease (HSCR) is defined by aganglionosis of the colon that leads to tonic contraction of the aganglionic region, inability to pass stool...

... cells, and are a model for studying how fate specification from multipotent progenitors is controlled. In mammals, the core gene regulatory network for melanocytes (their only pigment cell type) contains three transcription factors, Sox10, Pax3 and Mitf, with the latter considered a master regulator...

...Susanne C. Baess; Ann-Kathrin Burkhart; Sabrina Cappello; Annika Graband; Kristin Seré; Martin Zenke; Catherin Niemann; Sandra Iden ABSTRACT The barrier-forming, self-renewing mammalian epidermis comprises keratinocytes, pigment-producing melanocytes and resident immune cells as first-line host...

... circles) express key transcription factors for different cell fate specification programmes [Phox2bb (autonomic neuron), Sox10 (glia), Tfec (iridophore), Mitfa (melanocyte) and Pax3/7 (xanthophore)] and enter fate-cycling phase under influence of environmental signals (not shown). During the cycling phase...

... . Specifically, an autoinhibition-defective talin mutant strengthens and stabilizes integrin-based adhesions in melanocytes, which impinges on their ability to migrate. Mice with defective talin autoinhibition exhibit delays in melanoblast migration and pigmentation defects. Our results show that coordinated...

... established a role for a histone variant, H2a.z.2 , in specification of the melanocyte lineage from multipotent neural crest cells. H2a.z.2 silencing reduces the number of melanocyte precursors in developing zebrafish embryos and from mouse embryonic stem cells in vitro . We demonstrate that this histone...

...-of-function has been shown to impair axial elongation, neural tube (NT) closure and pigment cell development. Intriguingly, in contrast to axial elongation and NT closure, a Cdx role in neural crest (NC)-derived melanocyte/pigment cell development has not been reported in any other chordate species...

... downregulation in the dorsal neural tube is thus necessary for the switch between neural and melanocytic phases of NC development. * Present address: Program in Genomics of Differentiation, National Institute of Child Health and Human Development, 6B/3B309, Bethesda, MD 20892, USA ‡ Author...

...Thomas O’Reilly-Pol; Stephen L. Johnson Adult stem cells are crucial for growth, homeostasis and repair of adult animals. The melanocyte stem cell (MSC) and melanocyte regeneration is an attractive model for studying regulation of adult stem cells. The process of melanocyte regeneration can...

... and molecular mechanisms regulating pigmentation of head and neck are largely unknown. Melanocyte specification is controlled by the transcriptional activity of Mitf, but no general logic has emerged to explain how Mitf and progenitor transcriptional activities consolidate melanocyte and progenitor cell fates...

... on differentiation of a pluripotent stem cell population, whereas others depend on the division of differentiated cells. In development and in the hair follicle, pigmented melanocytes are derived from undifferentiated precursor cells or stem cells. However, differentiated melanocytes may also have proliferative...

... and is required in the neural crest for craniofacial development. Here, we establish a novel role for MEF2C in melanocyte development. Inactivation of Mef2c in the neural crest of mice results in reduced expression of melanocyte genes during development and a significant loss of pigmentation at birth due...

... form remain largely unknown. We use the pigment pattern of the adult zebrafish fin, with a variety of clonal and lineage analyses, to address these issues. Early embryonic labeling with lineage-marker-bearing transposons shows that all classes of fin melanocytes (ontogenetic, regeneration and kit...

...Shlomo Krispin; Erez Nitzan; Yachia Kassem; Chaya Kalcheim Colonization of trunk neural crest derivatives in avians follows a ventral to dorsal order beginning with sympathetic ganglia, Schwann cells, sensory ganglia and finally melanocytes. Continuous crest emigration underlies this process, which...

... equally to this work 18 12 2006 © 2007. 2007 Neural crest Migration Patterning Pigment pattern formation Melanophore Melanocyte Xanthophore Chromatophore Slow muscle Fast muscle Horizontal myoseptum cho you -type Sdf1a (Cxcl12a) Zebrafish The neural crest (NC...

...Chao-Tsung Yang; Stephen L. Johnson We developed a method to efficiently ablate a single cell type, the zebrafish melanocyte, and study the mechanisms of its regeneration. We found that a small molecule, (2-morpholinobutyl)-4-thiophenol (MoTP), specifically ablates zebrafish larval melanocytes...

... that a subpopulation of cells on the most dorsomedial aspect of the NT express the receptor tyrosine kinase Kit(previously known as c-kit), emigrate exclusively into the developing dermis,and then express definitive markers of the melanocyte lineage. These are thus melanocyte progenitor cells. They are generated...

...Julia Béjar; Yunhan Hong; Manfred Schartl Embryonic stem (ES) cell lines have provided very useful models to analyse differentiation processes. We present here the development of a differentiation system using ES-like cell lines from medaka. These cells were transfected with the melanocyte...

... failure to activate MITF in the normal number of melanoblasts. References Bertolotto, C., Abbe, P., Hemesath, T. J., Bille, K., Fisher, D. E., Ortonne, J. P. and Ballotti, R. (1998). Microphthalmia gene product as a signal transducer in cAMP-induced differentiation of melanocytes. J. Cell Biol...

[email protected]) 6 7 2001 © 2001. 2001 Xenopus Xwnt Frizzled Neural crest Xfz3 Slug Vertebrate embryo Melanocyte More than 20 Wnt genes have been identified to date and roles for many of these extracellular ligands have been defined in the control of embryonic patterning...