An assay system to study migratory behavior of cranial neural crest cells in Xenopus

An increasing number of genes are known to show expression in the cranial n eural crest area. So far it is very difficult to analyze their effect on ne ural crest cell migration because of the lack of transplantation techniques . This paper presents a simple method to study the migratory behavior of cr anial neural crest cells by homo-and heterotopic transplantations: Green fl uorescent protein (GFP) RNA was injected into one blastomere of Xenopus lae vis embryos at the 2-cell stage. The cranial neural crest area of stage 14 embryos was transplanted into the head or trunk region of an uninjected hos t embryo, and the migration was monitored by GFP fluorescence. The transpla nts were further examined by double immunostaining and confocal microscopy to trace migratory routes inside the embryo, and to exclude contaminations of grafts with foreign tissues. Our results demonstrate that we developed a highly efficient and reproducible technique to study the migratory ability of cranial neural crest cells. It offers the possibility to analyze genes involved in neural crest cell migration by coinjecting their RNA with that of GFP.