Project description:Premetamorphic Xenopus laevis tadpole tail respond to thyroid hormone by resorption. The goal of this experiment is to identify the genes involved in the TH-induced resorption tadpole tail and compare it to TH-induced proliferation and differentiation program in tadpole limb and brain. Xenopus tadpoles (NF54) were treated with 100 nM T3 in 0.1 x MMR for another 24h and 48h or without T3 for 48h (control group). NF 61 tadpoles were in 0.1 X MMR till they reached NF stage 62. The tails were dissected after the experiment. Keywords: development or differentiation design,organism part comparison design,reference design,replicate design,time series design
Project description:Premetamorphic Xenopus laevis tadpole tail respond to thyroid hormone by resorption. The goal of this experiment is to identify the genes involved in the TH-induced resorption tadpole tail and compare it to TH-induced proliferation and differentiation program in tadpole limb and brain. Xenopus tadpoles (NF54) were treated with 100 nM T3(triioodthyronine) in 0.1 x MMR for another 24h and 48h or without T3 for 48h (control group). NF 61 tadpoles were in 0.1 X MMR till they reached NF stage 62. The tails were dissected after the experiment.
Project description:In this experiment, we show transcription profiling of the Xenopus tropicalis tadpole tail tissue regeneration following removal. The tail tissues include its spinal cord, notochord, muscle, and dorsal aorta. We characterized the early, intermediate, and late stages of Xenopus tropicalis tail regeneration using the Xenopus tropicalis Affymetrix genome array in biological replicate.
Project description:Premetamorphic Xenopus laevis tadpoles brain ventricle cells respond to thyroid hormone by proliferation and subsequent differentiation. The goal of this experiment is to identify the genes involved in the TH-induced proliferation pathway in tadpole brain and compare it to TH-induced proliferation and differentiation program in tadpole limb. Xenopus tadpoles (NF54) were treated with 1 mM methimazole in 0.1 X MMR solution for 1 week to block the endogenous TH production and reduce the TH present in the system of the tadpole. They were then treated with 100 nM T3 in 1 mM methimazole and 0.1 x MMR for another 24h and 48h or without T3 for 48h (control group). Brains from the tadpoles were dissected at the end of the experiment. Keywords: development or differentiation design,organism part comparison design,reference design,replicate design,time series design
Project description:Premetamorphic Xenopus laevis tadpoles limb bud cells respond to thyroid hormone by proliferation and subsequent differentiation. The goal of this experiment is to identify the genes involved in the TH-induced proliferation pathway in developing tadpole limb bud and compare it to TH-induced proliferation and differentiation program in tadpole brain. Xenopus tadpoles (NF54) were treated with 1 mM methimazole in 0.1 X MMR solution for 1 week to block the endogenous TH production and reduce the TH present in the system of the tadpole. They were then treated with 100 nM T3 in 1 mM methimazole and 0.1 x MMR for another 24h and 48h or without T3 for 48h (control group). Limb buds were dissected at the end of the experiment. Keywords: development or differentiation design,organism part comparison design,reference design,replicate design,time series design
Project description:Amphibians such as the salamanders and the African clawed frog Xenopus are great models for regeneration studies because they can fully regenerate their lost organs. While axolotl can regenerate damaged organs throughout its lifetime, Xenopus has a limited regeneration capacity after metamorphosis. The ecotropic viral integrative factor 5 (Evi5), a cell-cycle-regulated protein that prevents cells from entering mitosis prematurely, is of great interest for it is highly upregulated in the limb blastema of axolotls, but its expression level remains unchanged in the fibroblastema of postmetamorphic frogs. Yet, its role in regeneration competent context in Xenopus has not been fully analyzed. Here we show that Evi5 is also upregulated in Xenopus tadpoles after limb and tail amputation, as it is in axolotls. Down-regulation of Evi5 with morpholino antisense oligos (Mo) impairs wound healing and blastema formation in limbs and tails in both axolotls and Xenopus tadpoles, suggesting a conserved function for Evi5 in regeneration. Using skin punch as a healing model we show that Evi5 is also involved in cell migration during wound healing. RNA-sequencing analysis shows that in addition to reduced signaling of Lepr, Pdgfa, Gdf5, evi5 Mo also downregulate lysine demethylases kdm6b and kdm7a, which are also required for limb regeneration. Thus, our results demonstrate that Evi5 plays a critical role in the regeneration of multiple systems in amphibians.
Project description:Epimorphic regeneration is the process by which complete regeneration of a complex structure such as a limb occurs through production of a proliferating blastema. This type of regeneration is rare among vertebrates but does occur in the African clawed frog Xenopus laevis, traditionally a model organism for the study of early development. Xenopus tadpoles can regenerate tails, limb buds and the lens of the eye, although the ability of the latter two organs to regenerate diminishes with advancing developmental stage. Using a heat shock inducible transgene that remains silent unless activated, we have established a stable line of transgenic Xenopus in which the BMP inhibitor Noggin can be over-expressed at any time during development. We have previously shown that activation of this transgene blocks regeneration of the tail and limb of Xenopus tadpoles. In the current study, we have taken advantage of this transgenic line to directly compare gene expression in same stage regenerating vs. non-regenerating hind limb buds. Using Affymetrix gene chip analysis, we have identified genes whose expression levels are linked to regenerative success. These include the BMP inhibitor Gremlin and the stress protein Hsp60 (no blastema in zebrafish). Analysis of overrepresented Gene Ontology functional groupings suggests that successful regeneration in the Xenopus hind limb depends on induction of stress response pathways. Furthermore, as expected, genes involved in embryonic development and growth are also significantly over-represented in regenerating early hind limb buds. Keywords: Differential expression, regeneration