Project description:Imprinted genes are critical for normal human growth and neurodevelopment. We developed a strategy to identify new DNA differentially methylated regions (DMRs), a hallmark of imprinted genes. Using genome-wide methylation profiling, candidate DMRs were selected by identifying CpGs with putative allelic differential methylation in normal biparental tissues. In parallel, we looked for parent of origin-specific DNA methylation patterns in paternally derived human androgenetic complete hydatidiform mole (AnCHM), and maternally derived mature cystic ovarian teratoma (MCT). Using this approach, we found known DMRs associated with imprinted genomic regions as well as new DMRs for known imprinted genes, NAP1L5 and ZNF597. Most importantly, novel candidate imprinted genes were identified. The paternally methylated DMR for one candidate, AXL, a receptor tyrosine kinase, was validated by methylation analyses in humans. Further validation in mouse embryos showed that Axl was expressed preferentially from the maternal allele in a DNA methylation–dependent manner. We have analyzed 3 androgenetic complete hydatidiform mole (AnCHM), 16 white blood cell (WBC), 1 mature cystic ovarian teratoma (MCT), 5 placenta, and 1 lymphoblastoid cell line paternal UPD4 sample
Project description:Maternal-effect mutations in components of the subcortical maternal complex (SCMC) of the human oocyte can cause early embryonic failure, gestational abnormalities and recurrent pregnancy loss. Enigmatically, they are also associated with DNA methylation abnormalities at imprinted genes in conceptuses, in the devastating gestational abnormality biparental complete hydatidiform mole (BiCHM) or in multi-locus imprinting disease (MLID). However, the developmental timing, genomic extent and mechanistic basis of these imprinting defects are unknown. Here, we studied methylation level of a women reported with familial recurrent hydatidiform mole and multiple pregnancy loss. Genotype analysis revealed homozygous mutation in KHDC3L. We obtained biparental mole from patient (Patient D) and compared it’s whole-genome methylation profile with respect to control placentas and sporadic mole (AnCHM) using Infinium MethylationEPIC BeadChip (WG-317-1001, Illumina). We also used endometrium samples from their respective mother for the comparison purposes. Molar conceptuses were observed with methylation defects at genome-wide level and profound loss of methylation at multiple genome-derived differentially methylated regions (gDMRs) confirming MLID.
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes
Project description:Androgenetic induced pluripotent stem cells (AgHiPSCs) were generated from androgenetic fibroblasts derived from a complete hydatidiform mole. AgHiPSCs can be used in regenerative medicine, for analysis of genomic imprinting, to study imprinting-related development, and for disease modeling in humans. To investigate the pluripotency state of AgHiPSCs, we analyzed their cellular and molecular characteristics (morphology, RT-PCR, qPCR, immunochemistry, and differentiation capacity in vitro and in vivo). We tested the DNA methylation status of imprinted genes using bisulfite sequencing and demonstrated the androgenetic identity of AgHiPSCs.
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes Sequence library of miRNAs from a single sample of human foetal mesenchymal stem cells. Results tested and confirmed by northern blotting. Please note that only raw data files are available for the embryonic and neual samples and thus, directly submitted to SRA (SRX547311, SRX548700, respectively under SRP042115/PRJNA247767)