Project description:We performed RNA-sequencing, ChIP-sequncing and Brif-sequencing on Rbbp5 knockout (KO) and wild-type (WT) mouse ICM and E5.0 epiblast. Our results showed that Rbbp5 KO lead to significant reduction of H3K4me3 modification at early blastocyst stage. The change in H3K4me3 landscape occured before the transcriptome change. Moreover, Rbbp5 KO specifically affected epiblast lineages the most at late blastocyst stage and the KO embryos died at E5.5.
Project description:Sperm-derived tsRNAs could act as acquired epigenetic factors and contribute to offspring phenotypes. However, the roles of specific tsRNAs in early embryo development remain to be elucidated. Here, by using pigs as a research model, we probed the tsRNA dynamics during spermatogenesis and sperm maturation, and demonstrated the delivery of tsRNAs from semen-derived exosomes to spermatozoa. By microinjection of the antisense sequence into in vitro fertilized oocytes and subsequent single-cell RNA-sequencing of embryos, we identified a specific functional tsRNA group (Gln-TTGs) that participate in the early cleavage of porcine preimplantation embryos, probably by regulating cell cycle-associated genes. Thus, specific tsRNAs present in mature spermatozoa play significant roles during preimplantation embryo development.
Project description:Differential gene expression in preimplantation embryos has been documented, but few focused studies have been done to compare differential expression in human embryos after embryonic genome activation and specifically how they relate to blastocyst development. We hypothesized that blastocyst stage embryos would differentially express genes in pathways important in cell division, mobilization, and processes important in embryo implantation including endometrial apposition, adhesion, and invasion. We analyzed gene expression in 6 preimplantation human embryos. Embryos studied were previously cryopreserved, supernumerary human embryos donated by couples who completed their family building through in vitro fertilization and had given specific consent for use in research. Embryos cryopreserved at the pronuclear stage were thawed and cultured to cleavage (Day 3) or blastocyst (Day 5) stage. Differential gene expression was first obtained through Affymetrix gene expression microarrays and then validated both in silico using the Gene Expression Omnibus and in vitro with RT-qPCR. Compared to cleavage stage embryos, blastocyst stage embryos differentially expressed 51 genes (p < 0.001), with overrepresentation in amoebiasis pathways and pathways in cancer.
Project description:Upon fertilization, extensive chromatin reprogramming occurs during preimplantation development. Growing evidence reveals species-dependent regulations of this process in mammals. ATP-dependent chromatin remodeling factor SMARCA5 (also known as SNF2H) is required for peri-implantation development in mice. However, the specific functional role of SMARCA5 in preimplantation development and if it is conserved among species remain unclear. Herein, comparative analysis of public RNA-seq datasets reveals that SMARCA5 is universally expressed during oocyte maturation and preimplantation development in mice, cattle, humans and pigs with species-specific patterns. Immunostaining analysis further describes the temporal and spatial changes of SMARCA5 in both mouse and bovine models. siRNA-mediated SMARCA5 depletion reduces the developmental capability and compromises the specification and differentiation of inner cell mass in mouse preimplantation embryos. Indeed, OCT4 is not restricted into the inner cell mass and the formation of epiblast and primitive endoderm disturbed with reduced NANOG and SOX17 in SMARCA5-deficient blastocysts. RNA-seq analysis shows SMARCA5 depletion causes limited effects on the transcriptomics at the morula stage, however, dysregulates 402 genes, including genes involved in transcription regulation and cell proliferation at the blastocyst stage in mice. By comparison, SMARCA5 depletion does not affect the development through the blastocyst stage but significantly compromises the blastocyst quality in cattle. Primitive endoderm formation is greatly disrupted with reduced GATA6 in bovine blastocysts. Overall, our studies demonstrate the importance of SMARCA5 in fostering the preimplantation development in mice and cattle while there are species-specific effects.
Project description:We examined expression profiles of genes that could be regulated by the MAPK pathways during mouse preimplantation development. We used Affymetrix GeneChips for microarray analysis, and three independent experiments were carried out. 8-cell stage embryos were treated or untreated with MAPK inhibitors, and blastocyst stage embryos were recruited for the study. Hybridization was carried out with the GeneChip Mouse Expression Set 430 or GeneChip Mouse Genome 430 2.0 Array following Affymetrix instructions. The array was then washed and stained using the GeneChip fluidics station according to the manufacture's instructions. Hybridized arrays were scanned using an Affymetrix GeneChip Scanner. Expression analysis was performed using GeneChip Operating Software 1.0 (Affymetrix) and scaled to an average probe set intensity of 500.
Project description:Maternal nutrition exclusively during the periconceptional period can induce remarkable effects on both oocyte maturation and early embryo development, which in turn can have lifelong consequences. The objective of this study was to evaluate the effect of maternal methionine supplementation on the transcriptome of bovine preimplantation embryos. Holstein cows were randomly assigned to one of two treatments differing in level of dietary methionine (1.89 Met vs. 2.43 Met % of metabolizable protein) from calving until embryo flushing. High quality preimplantation embryos from individual cows were pooled and then analyzed by RNA sequencing. A total of eight Holstein dairy cows were used in this study. Preimplantation embryos recovered from each cow were pooled in order to generate two replicates per cow assayed. Each pool consisted of 2-4 expanded blastocysts with excellent quality. Overall, a total of 16 embryo pools underwent RNA extraction, amplification, and subsequent sequencing.
Project description:Profiles of H3K4me3, H3K27ac, H3K27me3 and H3K9me3 in bovine GV oocytes and preimplantation embryos, and the characterization of chromatin accessibility in bovine blastocyst, inner cell mass and trophectoderm.