Project description:Xenopus is uniquely suited for identifying core features of successful CNS axon regeneration, because parts of its CNS (e.g., eye), regenerate axons throughout life, whereas others (e.g., hindbrain) do so only as tadpoles. To aid in the interpretation of bisulfite whole genome methylation sequencing (WGBS) on juvenile frog eye after optic nerve injury, and on hindbrain samples from tadpole and juvenile frog after spinal cord injury during the peak phase of axon regeneration, we performed ChIP-seq for histone modifications associated with active gene expression (H3K4me3 & H3K27ac) and repressed gene expression (H3K27me3 & H3K9me3) on these same tissues, as well as DNA-immunoprecipitation sequencing (DIP seq) for 5-hydroxymethyl cytosine (5hmC) on eye samples during optic nerve regeneration.
Project description:Poison frogs sequester chemical defenses from their diet of leaf litter arthropods for defense against predation. Little is known about the physiological adaptations that confer this unusual bioaccumulation ability. We conducted an alkaloid-feeding experiment with the Diablito poison frog (Oophaga sylvatica) to determine how quickly alkaloids are accumulated and how toxins modify frog physiology using quantitative proteomics. Diablito frogs rapidly accumulated the alkaloid decahydroquinoline within four days, and dietary alkaloid exposure modified protein abundance in the intestines, liver, and skin. Many proteins that increased in abundance with toxin accumulation are plasma glycoproteins, including the complement system and the toxin-binding protein saxiphilin. Other protein classes that change in abundance with toxin accumulation are membrane proteins involved in small molecule transport and metabolism. Overall, this work shows poison frogs can rapidly accumulate alkaloids, which alter carrier protein abundance, initiate an immune response, and alter small molecule transport and metabolism dynamics across tissues
Project description:Brachyury (Xbra/Xbra3) knock-down embryos of the frog Xenopus tropicalis were profiled to quantify neuro-mesodermal cell fate switches at a transcriptional level. Transcriptional profiling of Xbra/Xbra3 double morphants at early tadpole stage (RNA-Seq) in biological triplicates.
Project description:Xenopus is uniquely suited for identifying core features of successful CNS axon regeneration, because parts of its CNS (e.g., eye), regenerate axons throughout life, whereas others (e.g., hindbrain) do so only as tadpoles. We performed bisulfite whole genome bisulfite methylation sequencing (WGBS) on juvenile frog eye after optic nerve injury, and on hindbrain samples from tadpole and juvenile frog after spinal cord injury during the peak phase of axon regeneration, to compare tissue-related and injury-induced differences in DNA methylation among them.
Project description:Thyroid hormone (TH) controls the remodeling of the pancreas and the liver. TH-induces dedifferentiation of the exocrine pancreas to a progenitor state (Proc. Nat. Acad Sci. 105, 8962-8967 (2008)) and it remodels the endocrine pancreas (Dev. Biol. 328, 384-391 (2009)). The redifferentiated frog pancreas resembles closely the pancreas of other typical vertebrates. Two pancreas arrays were carried out. The first one studied gene expression changes at different developmental stages of Xenopus laevis during metamorphosis. The second array studies gene expression changes at varying times after the addition of TH to premetamorphic tadpoles. Keywords: cell cycle design,co-expression design,reference design,time series design Thyroid hormone (TH) controls remodeling of the pancreas. The micro array was carried out to identify changes in gene expression between the tadpole and frog pancreas. This is part 1, done on the 44K Xenopus platform. This dataset was used only for one pancreas experiment with several data points (control, 12h, 24h, 48h and frog). Each was made in triplicate. Samples in all 3 parts of the study received the same thyroid hormone levels.
