Project description:Distinct imprinting signatures and biased differentiation of human androgenetic and parthenogenetic embryonic stem cells [microarray]
Project description:Genomic imprinting is an epigenetic mechanism that results in parent-of-origin monoallelic expression of specific genes, which precludes uniparental development and underlies various diseases. Here we explored molecular and developmental aspects of imprinting in humans by generating exclusively-paternal human androgenetic embryonic stem cells (aESCs) and comparing them with exclusively-maternal parthenogenetic ESCs (pESCs) and bi-parental ESCs, establishing a pluripotent-cell system of distinct parental backgrounds. Analyzing the transcriptomes and methylomes of human aESCs, pESCs and bi-parental ESCs enabled the characterization of regulatory relations at known imprinted regions and uncovered new imprinted gene candidates within and outside known imprinted regions. Investigating the consequences of uniparental differentiation, we showed the known paternal-genome preference for placental contribution, revealed a novel bias towards liver differentiation, and implicated the involvement of the imprinted gene IGF2 in this process. Our results demonstrate the utility of parent-specific human ESCs for dissecting the role of imprinting in human development and disease.
Project description:Distinct imprinting signatures and biased differentiation of human androgenetic and parthenogenetic embryonic stem cells [RNA-Seq II]
Project description:Genomic imprinting is an epigenetic mechanism that results in parent-of-origin monoallelic expression of specific genes, which precludes uniparental development and underlies various diseases. Here, we explored molecular and developmental aspects of imprinting in humans by generating exclusively paternal human androgenetic embryonic stem cells (aESCs) and comparing them with exclusively maternal parthenogenetic ESCs (pESCs) and bi-parental ESCs, establishing a pluripotent cell system of distinct parental backgrounds. Analyzing the transcriptomes and methylomes of human aESCs, pESCs, and bi-parental ESCs enabled the characterization of regulatory relations at known imprinted regions and uncovered imprinted gene candidates within and outside known imprinted regions. Investigating the consequences of uniparental differentiation, we showed the known paternal-genome preference for placental contribution, revealed a similar bias toward liver differentiation, and implicated the involvement of the imprinted gene IGF2 in this process. Our results demonstrate the utility of parent-specific human ESCs for dissecting the role of imprinting in human development and disease.
Project description:Genomic imprinting is an epigenetic mechanism that results in parent-of-origin monoallelic expression of specific genes, which precludes uniparental development and underlies various diseases. Here, we explored molecular and developmental aspects of imprinting in humans by generating exclusively paternal human androgenetic embryonic stem cells (aESCs) and comparing them with exclusively maternal parthenogenetic ESCs (pESCs) and bi-parental ESCs, establishing a pluripotent cell system of distinct parental backgrounds. Analyzing the transcriptomes and methylomes of human aESCs, pESCs, and bi-parental ESCs enabled the characterization of regulatory relations at known imprinted regions and uncovered imprinted gene candidates within and outside known imprinted regions. Investigating the consequences of uniparental differentiation, we showed the known paternal-genome preference for placental contribution, revealed a similar bias toward liver differentiation, and implicated the involvement of the imprinted gene IGF2 in this process. Our results demonstrate the utility of parent-specific human ESCs for dissecting the role of imprinting in human development and disease.
Project description:In this study, mRNA expression profiles were examined by Illumina microarray in mouse embryonic stem cells (ESCs) derived from androgenetic (aESC), parthenogenetic (pESC) and fertilized (fESC) blastocysts. Results showed that 2394, 87 and 1788 mRNAs were differentially expressed in the aESCs vs. fESCs, pESCs vs. fESCs and aESCs vs. pESCs, respectively. Androgenetic, parthenogenetic and fertilized embryonic stem cell lines were established from androgenetic, parthenogenetically activated and fertilized blasotocyst. mRNA microarrays were repeated three times using passages 6, 7 and 8.
Project description:Genomic imprinting is an epigenetic phenomenon in which the expression of a gene is determined in a parent-of-origin-dependent manner. Imprinted genes play an important role in the normal growth and development of mammals, and mutations at the imprinting sites result in gene dysfunction and many genetic disorders. To identify new human imprinted differentially methylated regions (DMRs), we compared the global levels of DNA methylation in androgenetic induced pluripotent stem cells and parthenogenetic induced pluripotent stem cells using DNA methyl-capture sequencing analysis.
Project description:In this study, mRNA expression profiles were examined by Illumina microarray in mouse embryonic stem cells (ESCs) derived from androgenetic (aESC), parthenogenetic (pESC) and fertilized (fESC) blastocysts. Results showed that 2394, 87 and 1788 mRNAs were differentially expressed in the aESCs vs. fESCs, pESCs vs. fESCs and aESCs vs. pESCs, respectively.
Project description:The study of genomic imprinting in mammals started with analysis of parthenogenetic embryos. At the phenotypic level, embryos with two maternal genomes and no paternal genome proceed through early development unimpaired, and only begin to fail after implantation. The most recognizable early defect is reduced or non-existent trophoblast, the tissue that gives rise to the placenta. We applied the procedure for establishing Trophoblast Stem cells (TS cells) developed in the Rossant lab to parthenogenetic embryos, and were successful in making four different TS cell lines, three from MI oocyte derived blastocysts and one from MII derived blastocysts. Initial molecular characterization, including microarray analysis, indicates that these cells are indistinguishable from fertilized TS cells, with the single exception of null expression of the paternally expressed gene Snrpn. The only significant difference between parthenogenetic and fertilized TS cells was the frequency with which they could be derived. In our hands, fertilized blastocyst outgrowths produced TS cells at robust rates (10-12 colonies per blastocyst), while parthenogenetic blastocyst outgrowths produced only 4 colonies in 50 outgrowths, 100 times less frequently than fertilized embryos. This led us to hypothesize that those few TS cells that arose in parthenogenetic outgrowths were probably a result of very low frequency stochastic variation in the imprint status of a gene or genes required for either establishment or maintenance of stem cells, or both. The corollary to this hypothesis posits that the early failure of parthenogenetic embryos, and in particular parthenogenetic trophoblast, is a function of impaired stem cell function. This raises the intriguing possibility that microarray comparisons of parthenogenetic, fertilized and androgenetic blastocysts may reveal the identities of genes important for stem cell biology. To this end, my colleague Keith Latham, at the Fels Institute, Temple University, Philadelphia, made amplified cDNAs from pools of ten each of androgenetic, gynogenetic, or fertilized blastocysts. Three separate pools for each type of embryo were prepared for microarray analysis. The embryos were all produced by nuclear transfers between zygotes, a difficult technique that is Keith's special expertise. He used the Brady/Iscove protocol to generate quantitative 3' end biased cDNAs. We would like to compare the transcriptomes of these embryos using the MOE430 2.0 arrays. We expect that important insights into the biology of uniparental embryos in general, and stem cells in particular may be revealed. Experiment Overall Design: this experiment include 3 samples and 18 replicates