Skin Grafting in Xenopus laevis: A Technique for Assessing Development and Immunological Disparity

Skin grafting in the amphibian Xenopus laevis has been used to detect not only allogeneic antigens that differ by minor H antigens or by one MHC haplotype, but also to detect ontogeny-specific antigens (including both emerging adult- and disappearing larval-specific) during metamorphosis. To understand the mechanisms underlying allogeneic tolerance or immune responses against larval- and/or adult-specific antigens, a complete MHC homozygous, inbred strain is the most appropriate experimental model. The inbred J strain established in Japan is used here. Owing to complete histocompatibility, the inbred J strain shows no grafted skin rejection among the same strain of adult frogs, and its genuine homozygosity was reconfirmed by genomic sequence analysis in 2016. Therefore, the J strain enables immunologists and embryologists to understand evolutionary processes as well as immunological events and tissue remodeling mechanisms present during development. Furthermore, an F1 hybrid between the J strain and a GFP-labeled transgenic line is available from our laboratory and can be used as a model for long-term cell tracking. This protocol explains the methodology for skin grafting in X. laevis to determine immunological discrepancies between the host and donor. It is also possible to trace cell and tissue fates in the hosts during early embryogenesis and during complete development from larvae to adults, which is extremely difficult to perform using other species.