Project description:Background Methylation of CG dinucleotides constitutes a critical system of epigenetic memory in bony vertebrates, where it modulates gene expression and suppresses transposon activity. The genomes of studied vertebrates are pervasively hypermethylated, with the exception of regulatory elements such as transcription start sites (TSSs), where the presence of methylation is associated with gene silencing. This system is not found in the sparsely methylated genomes of invertebrates, and establishing how it arose during early vertebrate evolution is impeded by a paucity of epigenetic data from basal vertebrates. Methods We perform whole-genome bisulfite sequencing to generate the first genome-wide methylation profiles of a cartilaginous fish, the elephant shark Callorhinchus milii. Employing these to determine the elephant shark methylome structure and its relationship with expression, we compare this with higher vertebrates and an invertebrate chordate using published methylation and transcriptome data. Results Like higher vertebrates, the majority of elephant shark CG sites are highly methylated, and methylation is abundant across the genome rather than patterned in the mosaic configuration of invertebrates. This global hypermethylation includes transposable elements and the bodies of genes at all expression levels. Significantly, we document an inverse relationship between TSS methylation and expression in the elephant shark, supporting the presence of the repressive regulatory architecture shared by higher vertebrates. Conclusions Our demonstration that methylation patterns in a cartilaginous fish are characteristic of higher vertebrates imply the conservation of this epigenetic modification system across jawed vertebrates separated by 465 million years of evolution. In addition, these findings position the elephant shark as a valuable model to explore the evolutionary history and function of vertebrate methylation.
Project description:EBV immediate early protein ZEBRA was corroborated to interact with Pax5 which controls the fate of B cells. Ramos cells were infected with ZEBRA-expression lentivirus and positively infected cells were sorted, which were named Ramos-Lv-ZEBRA.
Project description:EBV immediate early protein ZEBRA was corroborated to interact with Pax5 which controls the fate of B cells. Ramos cells were infected with ZEBRA-expression lentivirus and positively infected cells were sorted, which were named Ramos-Lv-ZEBRA.
Project description:DNA methylation is tightly linked with gene expression regulation and has long been regarded a stable epigenetic mark in postmitotic cells. However, it recently became clear that postnatal brains appear to show stimulus-induced de novo CpG methylation or active demethylation related to neuronal plasticity. Due to striking homologies between the brains of birds and mammals, songbirds, especially the zebra finch, propose an attractive model for investigating the genome-wide DNA methylation profile and DNA methylation reconfiguration during brain development. In order to obtain a first genome-wide compendium of genes under putative DNA methylation control, we performed MethyCap-seq experiments on two recently cultured zebra finch cell lines, G266 and ZFTMA, also upon AZA-induced demethylation. First, the MethylCap-seq methodology in zebra finch was validated by comparison with RRBS generated data. Subsequently, quantitative analysis identified 30,700 significantly demethylated loci upon AZA-treatment. Further examination revealed enrichment of these regions in exons and promoters. To assess the influence of methylation on gene expression, RNA-seq experiments were performed. Comparison of the RNA-seq and MethylCap-seq results showed that at least 357 of the 3,457 AZA-upregulated genes are putatively regulated by methylation in the promoter region, for which a pathway analysis showed obvious enrichment for neurological networks. A subset of genes was validated using qPCR and CpG pyrosequencing. To our knowledge, this study provides the first genome-wide DNA methylation map of the zebra finch genome as well as a comprehensive set of genes of which transcription is under putative methylation control. MethylCap-seq and RNA-seq experiments were performed on DMSO- and AZA-treated zebra finch cell lines, i.e. G266 and ZFTMA. As a quality control, also an untreated ZFTMA sample was analyzed with MethylCap-seq and RRBS.
Project description:The data contain a proteomic analysis of cloacal fluid from 12 females across the reproductive cycle. Letters are used to indicate individuals, while numbers represent reproductive phases (1 - prereceptive, 2 - receptive, 3 - postreceptive). Due to the fact that the genome of the barn swallow is not fully annotated, proteins were mapped to zebra finch (Taeniopygia guttata) genome.