ABSTRACT: Transcriptional profiling of M0191xbdl vs M0171xCol-0 development embryos after 3 days and 6 days of fertilization Two conditional experiments: M0191xbdl vs M0171x Col-0, and two stages were compared: 3 days and 6 days after fertilization. 4 biological replicates for each experiment.
Project description:Transcriptional profiling of Q0990 x bdl vs Q0990 x Col-0 development embryos after 3days and 6 days of fertilization Two conditional experiments: Q0990 x bdl vs Q0990 x Col-0, and two satges was compared: 3days and 6 days after fertilization. . 4 biological replicates for each experiment. The submitter states that the Agilent Feature Extraction files have been lost: the original files was stored in a unrecoverable crashed computer, because the Base 2 in my institute is not in service anymore, so I can not re-download my file with the Agilent Feature
Project description:The Arabidopsis thaliana central cell, the companion cell of the egg, undergoes DNA demethylation prior to fertilization, but the targeting preferences and biological significance of this process remain unclear. Here, we show that active DNA demethylation mediated by the DEMETER DNA glycosylase accounts for all of the demethylation in the central cell, and preferentially targets small, AT-rich and nucleosome-depleted transposable elements. The vegetative cell, the companion cell of sperm, also undergoes DEMETER-dependent demethylation of similar sequences, and lack of DEMETER in vegetative cells causes reduced small RNA-directed DNA methylation of transposons in sperm. Our results demonstrate that demethylation in companion cells reinforces transposon methylation in plant gametes, thereby assuring stable silencing of transposable elements across generations Examination of DNA methylation in Arabidopsis endosperm, embryo, and pollen
Project description:We compared Agilent custom made expression microarrays with Illumina deep sequencing for RNA analysis of zebrafish embryos 5 days post fertilization, showing as expected a high degree of correlation of expression of a common set of 15,927 genes. This microarray study was designed to determine the gene expression profile of zebrafish embryos 5 days post fertilization. We also have compared expression with embryos that were injected with Mycobacterium marinum in the yolk at 2 hours post fertilization. After injections embryos were transferred into fresh egg water and incubated at 28M-BM-0C. 150 embryos of mock-injected embryos or 200 embryos injected with 12 CFU bacteria were snap-frozen in liquid nitrogen, and total RNA was isolated using TRIZOL reagent. The samples were analyzed in a technical duplicate using a dye swap experiment in order to check for dye bias.
Project description:Two major factors contributing to reduced fertility is use of exogenous hormones and old age. We use mouse model to study transcriptional and cell-cell communication changes upon superovulation and ageing in female reproductive cells - oocytes (OC) - and somatic cells - granulosa (GC) - surrounding them. In this experiment, we are testing how different GC transcriptional profiles correlate with embryo quality. 3M old C57BL6/J mice were naturally or superovulated and COCs singularized as described above. Granulosa cells were immediately flash frozen and matched oocytes were divided into individual drops of CARD media under mineral oil for fertilization. The oocytes were incubated in 37oC, 5% CO2 incubator for 30-40 min prior to fertilization. Frozen Mus musculus (C57BL6/J) male sperm straws were thawed and capacitated in Fertiup media for 30 min. Fertilization was achieved by combining 2.5 µl of activated sperm with 20 µl CARD media drop containing a single oocyte and incubated at 37oC, 5% CO2 for 3 hours. Then, oocytes were individually washed in Human Tubal Fluid (HTF) media drops and transferred to 20 µl HFT drops for overnight culture. After 24 hours, fertilization rate was evaluated by 2-cell stage and embryos transferred to G1+ media for further development. Early morula stage embryos were continuously collected based on observation 62-64 h post-fertilization. For late blastocysts, fertilization media was additionally changed to G2+ after 48h post- fertilization and blastocysts collected at 108h post-fertilization. For collection, the embryos were washed in DPBS and flash frozen. Granulosa cells and embryo samples were further processed by Smart-seq2, the cDNA amplification PCR cycle number for embryos was 16-17.
Project description:Some flowering plant and vertebrate genes are expressed primarily or exclusively from either the maternal or paternal allele, a phenomenon called genomic imprinting. Flowering plant imprinted gene expression has been described primarily in endosperm, a terminal nutritive tissue consumed by the embryo during seed development or after germination. Imprinted expression in Arabidopsis thaliana endosperm is orchestrated by differences in cytosine DNA methylation between the paternal and maternal genomes, as well as by Polycomb group (PcG) proteins. Currently only eleven imprinted Arabidopsis genes are known. Here we use extensive sequencing of cDNA libraries to identify many new paternally and maternally imprinted genes in A. thaliana endosperm, including transcription factors, proteins involved in hormone signaling, and epigenetic regulators. The imprinted status of many maternally-expressed genes is not altered by mutations in the DNA-demethylating glycosylase DEMETER, the DNA methyltransferase MET1 or the core PcG protein FIE, indicating that these genes are regulated by novel mechanisms or deposited from maternal tissues. We did not find any imprinted genes in the embryo. Our results demonstrate that imprinted gene expression, particularly from the maternal genome, is an extensive, mechanistically complex phenomenon that likely affects multiple aspects of seed development. Epigenetics Examination of genomic imprinting in Arabidopsis endosperm
Project description:Expression profiling of micro RNAs in mouse embryonic gonads before (11.5 days post coitum) and after (13.5 days post coitum) the critical period of sex determination
Project description:The general objective of the study was to determine modulation of gene expression by environmental factors, with a special emphasis on bone formation. For this reason, the specific period of treatment was chosen between 5-6 days post-fertilization (dpf), when bone formation and calcification are taking place. This experiment was designed as a new type of gravitational experiment, which we like to call \relative microgravity\, referring to the fact that the larvae first grow in hyper gravity for 5 days and are then returned to 1g normal gravity for 1 day. Zebrafish embryos were placed on a Large Diameter Centrifuge at 3 hpf, brought to a gravitational force of 3 g until 5 dpf. Reference embryos were kept in parallel at 1g (Inc). At 5dpf, one batch was left at 3g (3g), one batch was returned to 1g (3g>1g), while a third batch was returned to 1g, but left on the axis of the centrifuge (Axe; 3g>Axe). The experiment was repeated 4 times, each time with 4 batches of 60 larvae.
Project description:Camptothecin (CPT) is a plant alkaloid that specifically binds topoisomerase I (Topo I) inhibiting its activity and inducing double stranded breaks in the DNA, activating the genotoxic cell responses, and ultimately, it might trigger programmed cell death (PCD). We used microarrays to detail the changes in gene expression during as a consequence of CPT treatment in maize immature embryos. In four independent experiments immature embryos were plated on MS medium supplemented with 50 uM CPT and incubated during three days. Untreated embryos incubated on MS medium were used as controls.
Project description:Enucleated oocytes have the remarkable ability to reprogram somatic nuclei back to totipotency. Here we investigate genome-scale DNA methylation patterns after nuclear transfer and identify specific targets for DNA demethylation as well as NT specific limitations. We find that the ooplasm can confer similar demethylation patterns in both processes except at some repetitive element classes and that germ-line associated promoters are specifically targeted in NT. Comparison of DNA methylation patterns in murine fertilization and somatic cell nuclear transfer