Project description:Surgical removal of the lens from larval Xenopus laevis results in a rapid transdifferention of central corneal cells to form a new lens. The trigger for this process is understood to be an induction event arising from the unprecedented contact between the cornea and the vitreous humour that occurs following lens removal. The identity of this trigger is unknown. Here, we have used a functional transgenic approach to show that BMP signalling is required for lens regeneration and a microarray approach to identify genes that are upregulated specifically during this process. Analysis of the array data strongly implicates Wnt signalling and Pitx transcription factors in this process. Pluripotency genes, in contrast, are not upregulated, supporting the idea that corneal cells transdifferentiate without returning to a stem cell state. Furthermore, several genes from the array were expressed in the forming lens during embryogenesis. One of these, nipsnap1, is a known direct target of BMP signalling. We suggest that, as with tail regeneration, activation of multiple developmental signalling pathways could drive lens regeneration from the cornea.
Project description:In order to isolate novel genes regulating neural induction, we utilized a DNA microarray approach. As neural induction is thought to occur via the inhibition of BMP signaling, BMP signaling was inhibited in ectodermal cells by overexpression of a dominant-negative receptor. RNAs were isolated from control animal cap explants and from dominant-negative BMP receptor expressing animal caps and subjected to a microarray experiment using newly generated high-density Xenopus DNA microarray chips. Keywords = neural induction Keywords = BMP Keywords = nervous system Keywords = Xenopus Keywords = microarray Keywords: parallel sample
Project description:Bone Morphogenetic Proteins (BMPs), a subgroup of the TGF-beta superfamily, were originally isolated from bone on the basis of their ability to induce ectopic bone development. While BMPs are involved in a wide range of developmental and physiological functions, very few vertebrate target genes in this pathway have been identified. To identify target genes regulated by the BMP growth factor family in Xenopus, large-scale microarray analyses were conducted to discover genes directly activated by this factor in dissociated animal cap tissues treated with a combination of the protein synthesis inhibitor cycloheximide and BMP2. Keywords = Xenopus Keywords = BMP Keywords = microarray Keywords = development Keywords = target genes Keywords: parallel sample
Project description:Surgical removal of the lens from larval Xenopus laevis results in a rapid transdifferention of central corneal cells to form a new lens. The trigger for this process is understood to be an induction event arising from the unprecedented contact between the cornea and the vitreous humour that occurs following lens removal. The identity of this trigger is unknown. Here, we have used a functional transgenic approach to show that BMP signalling is required for lens regeneration and a microarray approach to identify genes that are upregulated specifically during this process. Analysis of the array data strongly implicates Wnt signalling and Pitx transcription factors in this process. Pluripotency genes, in contrast, are not upregulated, supporting the idea that corneal cells transdifferentiate without returning to a stem cell state. Furthermore, several genes from the array were expressed in the forming lens during embryogenesis. One of these, nipsnap1, is a known direct target of BMP signalling. We suggest that, as with tail regeneration, activation of multiple developmental signalling pathways could drive lens regeneration from the cornea. Three biological replicates of each of three sample types were analysed. For each replicate, lens tissue (L) was derived from 5 lenses dissected from stage 50 tadpoles. Similarly, 7-8 corneas dissected from stage 50 tadpoles from which the lens had been removed 3 days previously were pooled for each biologocal replicate (R). These samples should contain tissue that is changing from cornea to lens, to regenerate the missing lens. Finally, 7-8 corneas from eyes of tadpoles at the same stage that had the cornea lifetd but the lens left in place 3 days earlier were pooled for each biological replicate (sham operated corneas, designated S).
Project description:We implemented a functional genomics approach as a means to undertake a large-scale analysis of the Xenopus laevis inner ear transcriptome through microarray analysis. Microarray analysis uncovered genes within the X. laevis inner ear transcriptome associated with inner ear function and impairment in other organisms, thereby supporting the inclusion of Xenopus in cross-species genetic studies of the inner ear.
Project description:Bone Morphogenetic Proteins (BMPs), a subgroup of the TGF-ï¢ superfamily, were originally isolated from bone on the basis of their ability to induce ectopic bone development. While BMPs are involved in a wide range of developmental and physiological functions, very few vertebrate target genes in this pathway have been identified. To identify target genes regulated by the BMP growth factor family in Xenopus, large-scale microarray analyses were conducted to discover genes directly activated by this factor in dissociated animal cap tissues treated with a combination of the protein synthesis inhibitor cycloheximide and BMP2. Keywords = Xenopus Keywords = BMP Keywords = microarray Keywords = development Keywords = target genes
Project description:In order to isolate novel genes regulating neural induction, we utilized a DNA microarray approach. As neural induction is thought to occur via the inhibition of BMP signaling, BMP signaling was inhibited in ectodermal cells by overexpression of a dominant-negative receptor. RNAs were isolated from control animal cap explants and from dominant-negative BMP receptor expressing animal caps and subjected to a microarray experiment using newly generated high-density Xenopus DNA microarray chips. Keywords = neural induction Keywords = BMP Keywords = nervous system Keywords = Xenopus Keywords = microarray