Distinct imprinting signatures and biased differentiation of human androgenetic and parthenogenetic embryonic stem cells [microarray]
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ABSTRACT: 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: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:Parthenogenetic embryonic stem cells (PESCs) may have future utility in cell replacement therapies. We examined genome-wide mRNA expression profiles of monkey PESCs relative to ESCs derived from fertilized embryos. Several known paternally-imprinted genes were in the highly down-regulated group in PESCs compared to ESCs. Allele specific expression analysis of paternally-imprinted genes, i.e., those genes whose expression is down-regulated in PESCs, led to the identification of one novel candidate that was exclusively expressed from a paternal allele. Our findings suggest that PESCs could be used as a model for studying genomic imprinting and in the discovery of novel imprinted genes. Keywords: gene expression
Project description:Parthenogenetic embryonic stem cells (PESCs) may have future utility in cell replacement therapies. We examined genome-wide mRNA expression profiles of monkey PESCs relative to ESCs derived from fertilized embryos. Several known paternally-imprinted genes were in the highly down-regulated group in PESCs compared to ESCs. Allele specific expression analysis of paternally-imprinted genes, i.e., those genes whose expression is down-regulated in PESCs, led to the identification of one novel candidate that was exclusively expressed from a paternal allele. Our findings suggest that PESCs could be used as a model for studying genomic imprinting and in the discovery of novel imprinted genes. Keywords: gene expression The transcriptomes of rhesus monkey embryonic stem cell lines derived from IVF-produced embryos (Oregon Rhesus Macaque Embryonic Stem, ORMES-22) were compared with rhesus monkey parthenogenetic embryonic stem cell lines (heterozygous rhesus Parthenogenetic embryonic stem cell lines, rPESC-2) and homozygous rhesus Parthenogenetic embryonic stem cell lines, ORMES-9). Moreover, the transcriptomes of rPESC-2 line were also compared with ORMES-9. Finally, the adult somatic skin fibroblasts were analyzed. Three biological replicates of each cell line (A, B, C) were analyzed.
Project description:We asked whether oocyte number could be amplified through parthenogenesis of mouse oocytes, without requiring creation of a paternal genome and a genetically unique genome. Parthenotes develop to a blastocyst-like stage, and from this parthenogenetic ESCs (pESCs) can be derived with high efficiency. Like ESCs, pESCs maintain unlimited self-renewal and pluripotency, as well as germline competence. Further, we demonstrate that their expression pattern of imprinted maternal genes resembles that observed in oocytes. pESCs can be directed to differentiate into primordial germ cell-like cells (PGCLCs) and form oocytes that produce fertile pups and reconstitute ovarian endocrine functions. The transcriptome and imprinting pattern of PGCLCs differentiated from pESCs more closely approximate those of in vivo produced embryonic PGCs, than PGCLCs produced from ESCs. Parthenogenesis offers a promising route for deriving PGCLCs and amplifying oocytes by faithfully maintaining maternal genes, without fertilization.
Project description:We asked whether oocyte number could be amplified through parthenogenesis of mouse oocytes, without requiring creation of a paternal genome and a genetically unique genome. Parthenotes develop to a blastocyst-like stage, and from this parthenogenetic ESCs (pESCs) can be derived with high efficiency. Like ESCs, pESCs maintain unlimited self-renewal and pluripotency, as well as germline competence. Further, we demonstrate that their expression pattern of imprinted maternal genes resembles that observed in oocytes. pESCs can be directed to differentiate into primordial germ cell-like cells (PGCLCs) and form oocytes that produce fertile pups and reconstitute ovarian endocrine functions. The transcriptome and imprinting pattern of PGCLCs differentiated from pESCs more closely approximate those of in vivo produced embryonic PGCs, than PGCLCs produced from ESCs. Parthenogenesis offers a promising route for deriving PGCLCs and amplifying oocytes by faithfully maintaining maternal genes, without fertilization.
Project description:We asked whether oocyte number could be amplified through parthenogenesis of mouse oocytes, without requiring creation of a paternal genome and a genetically unique genome. Parthenotes develop to a blastocyst-like stage, and from this parthenogenetic ESCs (pESCs) can be derived with high efficiency. Like ESCs, pESCs maintain unlimited self-renewal and pluripotency, as well as germline competence. Further, we demonstrate that their expression pattern of imprinted maternal genes resembles that observed in oocytes. pESCs can be directed to differentiate into primordial germ cell-like cells (PGCLCs) and form oocytes that produce fertile pups and reconstitute ovarian endocrine functions. The transcriptome and imprinting pattern of PGCLCs differentiated from pESCs more closely approximate those of in vivo produced embryonic PGCs, than PGCLCs produced from ESCs. Parthenogenesis offers a promising route for deriving PGCLCs and amplifying oocytes by faithfully maintaining maternal genes, without fertilization.
Project description:In this study, miRNA 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 125, 42 and 99 miRNAs were differentially expressed in the aESCs vs. fESCs, pESCs vs. fESCs and aESCs vs. pESCs, respectively.
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:Genomic imprinting is a mechanism in which the expression of genes varies depending on their parent-of-origin. Imprinting occurs through differential DNA methylation and histone modifications on the two parental alleles, with most imprinted genes marked by CpG-rich differentially methylated regions (DMRs). DNA methylation profiling in cases of uniparental disomy (UPD) provides a unique system permitting the study of DNA derived from a single parent (PMID: 20631049). Approximately 70 human imprinted genes have been described, and imprinted loci have been associated with diseases such as diabetes and cancer. We profiled parent of origin DNA methylation marks to find novel imprinted loci. Methods: We have an unprecedented collection of whole blood DNA from XX patients with UPD covering 18 different chromosomes, allowing for the efficient detection of DMRs associated with imprinted genes for 84% of the human genome. Our study is complimented with Ovarian Teratoma DNA (maternal DNA) and Complete hydatidiform Mole (paternal DNA). DNA methylation was profiled using Illumina Infinium 450K Methylation BeadArrays. Imprinted DMRs were defined by sites at which the maternal and paternal methylation levels diverged significantly from the biparental average. We confirmed novel DMRs by bisulfite sequencing of informative trios and SequenomEpiTYPER assays. Allelic specific gene expression studies were also performed by RNA sequencing in independent biparental controls. Findings: Our results provide for the first comprehensive map of the human imprintome, doubling the number of known imprinted regions. We identified a total of 71 DMRs, 41 of which were novel. 27 novel DMRs were maternally methylated and 14 were paternally methylated. We identified DMRs on chromosomes 5, 21 and 22 previously considered devoid of imprinting, highlighting potential parent-of-origin effects in chromosomal aneuploidies such as Down syndrome. We also found DMRs in genes associated with Schizophrenia and epilepsy. Interpretation: Our data provide the first comprehensive genome-wide map of imprinted sites in the human genome, and provide novel insights into potential parent-of-origin effects in human disorders. 66 UPD samples analyzed in total, From each individual, whole bllod DNA was extracted and global DNA methylation levels were assessed using Illumina Infinium HumanMethylation450 BeadChip.