More Than Just a Bandage: Closing the Gap Between Injury and Appendage Regeneration

The remarkable regenerative capabilities of amphibians have captured the attention of biologists for centuries. The frogs Xenopus laevis and Xenopus tropicalis undergo temporally restricted regenerative healing of appendage amputations and spinal cord truncations, injuries that are both devastating and relatively common in human patients. Rapidly expanding technological innovations have led to a resurgence of interest in defining the factors that enable regenerative healing, and in coupling these factors to human therapeutic interventions. It is well-established that early embryonic signaling pathways are critical for growth and patterning of new tissue during regeneration. A growing body of research now indicates that early physiological injury responses are also required to initiate a regenerative program, and that these differ in regenerative and non-regenerative contexts. Here we review recent insights into the biophysical, biochemical, and epigenetic processes that underlie regenerative healing in amphibians, focusing particularly on tail and limb regeneration in Xenopus. We also discuss the more elusive potential mechanisms that link wounding to tissue growth and patterning

Protocol for tail vein injection in Xenopus tropicalis tadpoles

Summary: Functional studies in post-embryonic Xenopus tadpoles are challenging because embryonic perturbations often lead to developmental consequences, such as lethality. Here, we describe a high-throughput protocol for tail vein injection to introduce fluorescent tracers into tadpoles, which we have previously used to effectively inject morpholinos and molecular antagonists. We describe steps for safely positioning tadpoles onto agarose double-coated plates, draining media, injecting into the ventral tail vein, rehydrating plates, and sorting tadpoles by fluorescence with minimal injury for high-throughput experiments.For complete details on the use and execution of this protocol, please refer to Kakebeen et al.,1 Patel et al.,2 and Patel et al.,3 : Publisher’s note: Undertaking any experimental protocol requires adherence to local institutional guidelines for laboratory safety and ethics

A temporally resolved transcriptome for developing ???Keller??? explants of the Xenopus laevis dorsal marginal zone

Background Explanted tissues from vertebrate embryos reliably develop in culture and have provided essential paradigms for understanding embryogenesis, from early embryological investigations of induction, to the extensive study of Xenopus animal caps, to the current studies of mammalian gastruloids. Cultured explants of the Xenopus dorsal marginal zone (???Keller??? explants) serve as a central paradigm for studies of convergent extension cell movements, yet we know little about the global patterns of gene expression in these explants. Results In an effort to more thoroughly develop this important model system, we provide here a time???resolved bulk transcriptome for developing Keller explants. Conclusions The dataset reported here provides a useful resource for those using Keller explants for studies of morphogenesis and provide genome???scale insights into the temporal patterns of gene expression in an important tissue when explanted and grown in culture