Project description:Leptin binding to the leptin receptor (LepR) causes rapid signaling to the nucleus. We investigated the early (2 hr) transcriptional response to acute leptin injectio (intracerebroventricular) in the preoptic area/hypothalamus/pituitary of juvenile Xenopus laevis frogs. Frogs were given i.c.v. injections of 0.6% saline or recombinant X. laevis leptin (rxLeptin; 20 ng/g BW) and 2 hrs later killed and the preoptic area/hypothalamus/pituitary dissected.
Project description:Comprehensive RNA-seq experiments to measure the expression of homoeologs across different tissues, as a part of the Xenopus laevis genome project. This work is funded by Agency Japanese Ministry of Education, Culture, Sports, Science and Technology (MEXT; "Genome Science" Grant ID 221S0002). Collect mRNA from whole tissue; two female frogs were used as donors for most tissues (Taira dataset for one frog, Ueno dataset for the other frog); testis samples were collected from two male frogs (sibling of two female donors)
Project description:Leptin binding to the leptin receptor (LepR) causes rapid signaling to the nucleus. We investigated the early (2 hr) transcriptional response to acute leptin injectio (intracerebroventricular) in the preoptic area/hypothalamus/pituitary of juvenile Xenopus laevis frogs.
Project description:Suppressing spurious cryptic transcription by a repressive intragenic chromatin state featuring trimethylated lysine 36 on histone H3 (H3K36me3) and DNA methylation is critical for maintaining self-renewal capacity in mouse embryonic stem cells. In yeast and nematodes, such cryptic transcription is elevated with age, and reducing the levels of age-associated cryptic transcription extends yeast lifespan. Whether cryptic transcription is also increased during mammalian aging is unknown. We show for the first time an age-associated elevation in cryptic transcription in several stem cell populations, including murine hematopoietic stem cells (mHSCs) and neuronal stem cells (NSCs) and human mesenchymal stem cells (hMSCs). Using DECAP-seq, we mapped and quantified age-associated cryptic transcription in hMSCs aged in vitro. Regions with significant age-associated cryptic transcription have a unique chromatin signature: decreased H3K36me3 and increased H3K4me1, H3K4me3, and H3K27ac with age. Furthermore, genomic regions undergoing such age-dependent chromatin changes resemble known promoter sequences and are bound by the promoter-associated protein TBP even in young cells. Hence, the more permissive chromatin state at intragenic cryptic promoters likely underlies the increase of cryptic transcription in aged mammalian stem cells.
Project description:Chinese and Philippine strains of the blood fluke Schistosoma japonicum present clear and distinctive phenotypes in areas of fecundity, pathology, drug sensitivity and immunology. Despite these differences large scale sequencing efforts have focused solely on Chinese mainland strain of the parasite. We have undertaken a comparative genomic hybridisation (CGH) approach to highlight some of the structural differences in the genome of two of the major geographical isolates of S. japonicum. We identified seven distinct regions of the S. japonicum genome that present differential CGH between Chinese and Philippine strains of the blood fluke Schistosoma japonicum, representing either deletion or duplication regions in the Philippine strain. Within these regions, genes that may be related to phenotypical differences are identified and discussed.
Project description:Chinese and Philippine strains of the blood fluke Schistosoma japonicum present clear and distinctive phenotypes in areas of fecundity, pathology, drug sensitivity and immunology. Despite these differences large scale sequencing efforts have focused solely on Chinese mainland strain of the parasite. We have undertaken a comparative genomic hybridisation (CGH) approach to highlight some of the structural differences in the genome of two of the major geographical isolates of S. japonicum. We identified seven distinct regions of the S. japonicum genome that present differential CGH between Chinese and Philippine strains of the blood fluke Schistosoma japonicum, representing either deletion or duplication regions in the Philippine strain. Within these regions, genes that may be related to phenotypical differences are identified and discussed. Genomic DNA was isolated from adult (7 week post cercarial challenge) Schistosoma japonicum Chinese and Philippine isolates and separate maleand femalesamples comparatively hybridised on an Agilent customn designed oligo microarray.
Project description:Induction of Xenopus laevis larvae metamorphosis is dependent on exposure to TH. Metamorphosis involves the regression, growth or remodeling of almost all the tissues in the animals body. Metamorphosis in frogs is induced by thyroid hormone. Each organ system has a unique morphological and genetic program that it follows while undergoing metamorphosis involving both the upregulation and downregulation of genes. In this array we examined the change in gene expression in the tail of larvae undergoing precocious metamorphosis following induction with thyroid hormone.
2010-07-01 | GSE22643 | GEO
Project description:Cytonuclear discordance, reticulation and cryptic diversity in one of North America's most common frogs
Project description:Variation in gene expression is known to be important for morphological evolution, however little is known about its general propensity. Here we examine a pair of frogs M-bM-^@M-^S Xenopus laevis and Xenopus tropicalis M-bM-^@M-^S with highly similar embryology, and ask how their transcriptomes compare. Despite separation for over ~30-90 million years we found a strong conservation in gene expression in the vast majority of the expressed orthologs. There were a significant number of changes in the level of expression of genes. Changes in timing of expression, heterochrony, were much less common, and were often found in genes and pathways that reflect responses to selective features of the environment. Differences in gene expression levels were concentrated in the earliest embryonic stages. We propose that different evolutionary rates across developmental stages may be explained by the stabilization of cell fate determination pathways in later stages. 96 microarrays, across developmental stages in Xenopus laevis and Xenopus tropicalis in wildtype embryos. For each of the two timecourse indepenent triplicates (clutches) were generated.
Project description:Suppressing spurious cryptic transcription by a repressive intragenic chromatin state featuring trimethylated lysine 36 on histone H3 (H3K36me3) and DNA methylation is critical for maintaining self-renewal capacity in mouse embryonic stem cells. In yeast and nematodes, such cryptic transcription is elevated with age, and reducing the levels of age-associated cryptic transcription extends yeast lifespan. Whether cryptic transcription is also increased during mammalian aging is unknown. We show for the first time an age-associated elevation in cryptic transcription in several stem cell populations, including murine hematopoietic stem cells (mHSCs) and neuronal stem cells (NSCs) and human mesenchymal stem cells (hMSCs). Using DECAP-seq, we mapped and quantified age-associated cryptic transcription in hMSCs aged in vitro. Regions with significant age-associated cryptic transcription have a unique chromatin signature: decreased H3K36me3 and increased H3K4me1, H3K4me3, and H3K27ac with age. Furthermore, genomic regions undergoing such age-dependent chromatin changes resemble known promoter sequences and are bound by the promoter-associated protein TBP even in young cells. Hence, the more permissive chromatin state at intragenic cryptic promoters likely underlies the increase of cryptic transcription in aged mammalian stem cells.