Oral communication, iL28

Official XXIst International Pigment Cell Conference website - 21-24 Sept 2011, Bordeaux - France | updated: September 04 2011

Pigmentation in non-mouse models - fishing for insight, not just horsing around ?

Pigmentation is a prominent feature of almost all vertebrates and consequently numerous species have been used in its study. Whilst the mouse, with its superb genetics and long history of collecting mutants, is the dominant model system, other models offer specific advantages. In this talk I will be briefly outline the roles played by some of these complementary systems. Whereas mammals have just melanocytes and so are depleted in their complement of pigment cell-types, poikilothermic vertebrates show the full diversity, with up to 7 different types. Amphibians, and more recently fish, have provided excellent opportunities to characterise these different cell-types and their origin from neural crest. Given the excellent genetics of fish and the genetic and embryological accessibility of their embryos, it is understandable that fish models, particularly zebrafish and medaka, have been the source of substantial insight into pigment cell development. These studies have begun to characterise the intermediate steps in the development of pigment cells from the neural crest, and have identified numerous genes required for their development. These systems allow fine dissection of the processes of pigment cell specification, survival and differentiation, and are now being combined with mathematical modeling to allow a more rigorous understanding of the gene regulatory networks of pigment cell development. Both Xenopus and fish embryos are highly amenable to small molecule screening in vivo, and have identified many compounds with specific effects on pigment cell development; where such compounds affect melanocytes, they can often be applied to study of mammalian cells too. Fish models of melanoma have a long history and will continue to provide excellent opportunities for dissection of the mechanisms of cancer formation and progression and for drug development. One novel application of fish pigmentation concerns the recent design of an iridophore-based assay for receptor tyrosine kinase inhibitors. The fascinating topics of pigment pattern formation and pigment pattern evolution have been dependent upon identification of tractable case studies, with Danio fish, dogs, mice and diverse birds being most important to date. Finally, domestic animals, especially dog, chicken and horses, provide excellent case studies for analysing the comparative genetics of pigmentation. Despite the dominance of the mouse (and human) systems, other mammalian and non-mammalian species have made major contributions and will continue to do so.

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