Project description:Recent success in the derivation of mouse haploid embryonic stem cells from androgenetic blastocysts (ahESCs) has provided new avenues for the generation of genetically modified animals. However, the efficiency to produce viable transgenic mice via intracytoplasmic ahESCs injection (ICAI) was very low, which may correlate with the aberrant regulation of imprinted genes. Here we designed to delete the paternal imprinted gene H19 by CRSPR-Cas9 system combined with homologous recombination. The H19 deleted (H19Î) ahESCs maintained haploidy and genome integrity, expressed pluripotency markers, differentiated into embryoid bodies (EBs), and contributed to chimeras after blastocyst injection. These cells exhibited similar imprinting features with sperm cells, and can produce fertile progenies after ICAI at a high efficiency. More importantly, it is feasible to perform genetic manipulations in H19Î ahESCs, and the genomic modifications can be properly transmitted to offspring. Our study will benefit the reproductive medicine in curing the hereditary genetic diseases and infertility in the future. The copy number variations of the two H19Î ahESC lines were analyzed by the SurePrint G3 Mouse CGH 4Ã180 K microarrays (Agilent). Wild-type OG-3 ahESCs were used as reference.
Project description:Recent success in the derivation of mouse haploid embryonic stem cells from androgenetic blastocysts (ahESCs) has provided new avenues for the generation of genetically modified animals. However, the efficiency to produce viable transgenic mice via intracytoplasmic ahESCs injection (ICAI) was very low, which may correlate with the aberrant regulation of imprinted genes. Here we designed to delete the paternal imprinted gene H19 by CRSPR-Cas9 system combined with homologous recombination. The H19 deleted (H19Δ) ahESCs maintained haploidy and genome integrity, expressed pluripotency markers, differentiated into embryoid bodies (EBs), and contributed to chimeras after blastocyst injection. These cells exhibited similar imprinting features with sperm cells, and can produce fertile progenies after ICAI at a high efficiency. More importantly, it is feasible to perform genetic manipulations in H19Δ ahESCs, and the genomic modifications can be properly transmitted to offspring. Our study will benefit the reproductive medicine in curing the hereditary genetic diseases and infertility in the future.
Project description:Our lab first derived mouse androgenetic haploid embryonic stem cells (AG-haESCs) and demonstrated that AG-haESCs can be used as an “artificial spermatids” to generate gene-edited semi-cloned (SC) mice through intracytoplasmic injection (ICAHCI) into mature oocyte, even though the birth efficiency is very low. Further we proved that H19-DMR and IG-DMR were the main barrier to generate viable mice through androgenetic and parthenogenetic haESCs. More importantly, AG-haESCs mediated SC technology combined with CRISPR-Cas9 is a powerful tool to generate gene-modified mouse models and carry out genetic screening at organismal level. However, it is still not clear how the H19-DMR and IG-DMR coordinately regulate SC embryo development. Here, we found that the H19-DMR and IG-DMR regulate the development of SC embryos in spatio-temporal scales. Firstly, we found that the H19-DMR and IG-DMR are not indispensable for the development of preimplantation of SC embryos. Secondly, H19-DMR is essential for the development of SC embryos in mid-gestation and IG-DMR takes effect in late-gestation. Further, the maintenance of paternal H19-DMR methylation status and deletion of paternal H19 transcription unit play a key role in the structures and transport functions of SC embryo placenta. Importantly, AG-haESCs carrying triple deletions, including H19, H19-DMR and IG-DMR, can further improve the efficiency in generation of viable, normal-size, and fertile mice.
Project description:Haploid stem cells offer an easy-to-manipulate genetic system and therefore have great values for studies of recessive phenotypes. Here, we show that mouse androgenetic haploid ES (ahES) cell lines can be established by transferring sperm into enucleated oocyte. The ahES cells maintain haploidy and stable growth over 30 passages, express pluripotent markers, possess the ability to differentiate into all three germ-layers in vitro and in vivo, and contribute to germline of chimeras when injected into blastocysts. Although epigenetically distinct from sperm cells, the ahES cells can produce viable and fertile progenies after intracytoplasmic injection into mature oocytes. The oocyte injection procedure can also produce viable transgenic mice from genetically engineered ahES cells. We used microarrays to compare the global programme of gene expression among ahES cells, normal diploid ES cells, MEF cells and round sperm cells and found that gene expression pattern of ahES cells was highly similar with ES cells but was distinct from MEF cells and round sperms. Androgenetic haploid ES cells were FACS sorted to harvest the G0/G1 phase haploid cells. Total RNA were extracted from three ahES cell lines (AH129-5, AH129-N1, AH129-NC1, all 129Sv genetic background), two ES cell lines ( CS1-1, R1, 129Sv background), MEF cells and round sperm and hybridized with Affymetrix GeneChip 430 2.0 array. Data were collected and analyzed to compare their gene expression pattern.
Project description:Haploid stem cells offer an easy-to-manipulate genetic system and therefore have great values for studies of recessive phenotypes. Here, we show that mouse androgenetic haploid ES (ahES) cell lines can be established by transferring sperm into enucleated oocyte. The ahES cells maintain haploidy and stable growth over 30 passages, express pluripotent markers, possess the ability to differentiate into all three germ-layers in vitro and in vivo, and contribute to germline of chimeras when injected into blastocysts. Although epigenetically distinct from sperm cells, the ahES cells can produce viable and fertile progenies after intracytoplasmic injection into mature oocytes. The oocyte injection procedure can also produce viable transgenic mice from genetically engineered ahES cells. We used microarrays to compare the global programme of gene expression among ahES cells, normal diploid ES cells, MEF cells and round sperm cells and found that gene expression pattern of ahES cells was highly similar with ES cells but was distinct from MEF cells and round sperms.
Project description:Generation of haploid gametes in vitro can potentially address gamete failure-based infertility.This study reports complete in vitro meiosis from murine ESC-derived PGCLCs resulting in the formation of male spermatid-like cells (SLCs) capable of producing viable fertile offspring via intracytoplasmic sperm injection (ICSI).Our findings provide the basis for generation of haploid spermatids in vitro in human, the generation of transgenic animals, and the use of this system to investigate mechanisms of meiosis.
Project description:We reported a kind of new haploid embryonic stem cell, human haploid androgenetic embryonic stem cell, which kept the sperm characteristic epigenetic modification patterns for imprinting genes. In this study, two human haploid androgenetic embryonic stem cell lines (ha-AGHESC) and two human haploid parthenogenetic embryonic stem cell lines (ha-PGHESC) with somatic control and diploid HESC control, were processed with RNA-sequencing (RNA-seq) and whole genome bisulfite sequencing (WGBS). We showed that the reconstructed semi-clone HESCs were similar to the diploid HESC in transcriptome and the methylome especially related to the known human imprinting genes. The raw data of WGBS and bulk RNA-seq are deposited at Genome Sequence Archive (GSA) of Human with accession number HRA004100.
Project description:Abstract: Dysregulation of the imprinted H19/IGF2 locus can lead to Silver-Russell Syndrome (SRS) in humans. However, the mechanism of how abnormal H19/IGF2 expression contributes to various SRS phenotypes remains unclear, largely due to incomplete understanding of the developmental functions of these two genes. We previously generated a mouse model with humanized H19/IGF2 ICR (hIC1) on the paternal allele that exhibited H19/Igf2 dysregulation together with SRS-like growth restriction and perinatal lethality. Here we dissect the role of H19 and Igf2 in cardiac and placental development utilizing multiple mouse models with varying levels of H19 and Igf2. We report severe cardiac defects such as ventricular septal defects (VSDs) and thinned myocardium, placental anomalies including thrombosis and vascular malformations, together with growth restriction in mouse embryos that correlated with the extent of H19/Igf2 dysregulation. Transcriptomic analysis using cardiac endothelial cells of these mouse models shows that H19/Igf2 dysregulation disrupts pathways related to extracellular matrix (ECM) and proliferation of endothelial cells. Our work links the heart and placenta through regulation by H19 and Igf2, demonstrating that accurate dosage of both H19 and Igf2 is critical for normal embryonic development, especially related to the cardiac-placental axis. Methods: E12.5 hearts were lysed with Collagenase, Dispase II, and DNase I. Cardiac endothelial cells were collected using MACS CD31 microbeads and RNA was isolated using RNeasy Micro kit. After confirming RNA integrity using Bioanalyzer, mRNA library was generated from 25ng RNA using NEBNext Poly(A) mRNA Magnetic Isolation Module and Ultra II RNA Library Prep Kit. Library quality was assessed by Bioanalyzer and TapeStation. Sequencing was performed on NovaSeq 6000. Quality of raw fastq reads was assessed using FastQC version 0.11.5. Reads were aligned to the GRCm38/mm10 reference using STAR version 2.4.0i with default parameters and maximum fragment size of 2000 bp. Properly paired primary alignments were retained for downstream analysis using Samtools version 1.9. Count matrices were generated using FeatureCounts version 1.6.2 against RefSeq gene annotation and read into DESeq2 to perform normalization and statistical analysis.
Project description:The use of two inhibitors of Mek1/2 and Gsk3β (2i) promotes the generation of mouse diploid and haploid embryonic stem cells (ESCs) from the inner cell mass of biparental and uniparental blastocysts, respectively. However, a system enabling long-term maintenance of imprints in ESCs has proven challenging. Here, we report that usage of a two-step a2i (alternative two inhibitors of Src and Gsk3β, TSa2i) derivation/culture protocol results in the establishment of androgenetic haploid ESCs (AG-haESCs) with stable DNA methylation at paternal DMRs (differentially DNA methylated regions) up to passage 60 that can efficiently support generating mice upon oocyte injection. We also show coexistence of H3K9me3 marks and ZFP57 bindings with intact DMR methylations. Furthermore, we demonstrate that TSa2i-treated AG-haESCs are a heterogeneous cell population regarding paternal DMR methylation. Strikingly, AG-haESCs with late passages display increased paternal-DMR methylations and improved developmental potential compared to early-passage cells, in part through the enhanced proliferation of H19-DMR hypermethylated cells. Together, we establish AG-haESCs that can long-term maintain paternal imprints.