Chromatin landscapes in mouse haploid stem cells [ChIP-seq]
Ontology highlight
ABSTRACT: We generate histone modification profiles and DNA methylation profiles of mouse haploid embryonic stem cells. By comparison to mouse diploid ESCs and MEFs, we found the similar chromatin landscapes between haESCs and mESCs, which reveal the self-renew ability and pluripotency in haESCs. Besides, haESCs specific chromatin landscapes show its sperm-like functions.
Project description:We generate histone modification profiles and DNA methylation profiles of mouse haploid embryonic stem cells. By comparison to mouse diploid ESCs and MEFs, we found the similar chromatin landscapes between haESCs and mESCs, which reveal the self-renew ability and pluripotency in haESCs. Besides, haESCs specific chromatin landscapes show its sperm-like functions.
Project description:Mammalian haploid embryonic stem cells (haESCs) provide new possibilities for large-scale genetic screens because they bear only one copy of each chromosome. However, haESCs are prone to spontaneous diploidization through unknown mechanisms. Here, we report that a small molecule combination could restrain mouse haESCs from diploidization by impeding exit from naïve pluripotency and by shortening the S-G2/M phases. Combined with 2i and PD166285, our chemical cocktail could maintain haESCs in the haploid state for at least five weeks without fluorescence-activated cell sorting (FACS) enrichment of haploid cells. Taken together, we established an effective chemical approach for long-term maintenance of haESCs, and highlighted that proper cell cycle progression was critical for the maintenance of haploid state.
Project description:Haploid pluripotent stem cells, such as haploid embryonic stem cells (haESCs), facilitate the genetic study of recessive traits. In vitro, fish haESCs maintain haploidy in both undifferentiated and differentiated states, but whether mammalian haESCs can preserve pluripotency in the haploid state has not been tested. Here, we report that mouse haESCs can differentiate in vitro into haploid epiblast stem cells (haEpiSCs), which maintain an intact haploid genome, unlimited self-renewal potential, and durable pluripotency to differentiate into various tissues in vitro and in vivo. Mechanistically, the maintenance of self-renewal potential depends on the Activin/bFGF pathway. We further show that haEpiSCs can differentiate in vitro into haploid progenitor-like cells.
Project description:Haploid cells are amenable for genetic analysis because they contain only one set of chromosomes.Here,we report the derivation of haESCs from androgenetic blastocysts. These cells, which we designated AG-haESCs, express classical ESC markers, are pluripotent, and contribute to various tissues including the germline upon injection into diploid blastocysts. We used microarrays to compare the gene expression levels among androgenetic haploid embryonic stem cell lines(AG-haESC) E14 and male mouse embryonic fibroblasts (MEFs) and identified that most paternally imprinted genes were down-regulated and the maternally imprinted genes were up-regulated.
Project description:Diploid and haploid strains often exhibit different tolerance to variety of stresses. Transcriptome of acclimation to ethanol stress in diploid and haploid strain of Saccharomyces cerevisiae was analyzed. We analyzed transcriptome profiles of diploid and haploid strains in the presence of ethanol.
Project description:Haploid cells are amenable for genetic analysis because they contain only one set of chromosomes.Here,we report the derivation of haESCs from androgenetic blastocysts. These cells, which we designated AG-haESCs, express classical ESC markers, are pluripotent, and contribute to various tissues including the germline upon injection into diploid blastocysts. We used microarrays to compare the gene expression levels among androgenetic haploid embryonic stem cell lines(AG-haESC) E14 and male mouse embryonic fibroblasts (MEFs) and identified that most paternally imprinted genes were down-regulated and the maternally imprinted genes were up-regulated. To avoid the influence of diploidized cells on the expression profile, we collected samples from FACS of cells at G1/G0 stage by staining Hochest 33342. We used E14,which was a male embryonic stem cell lines, and MEFs isloated from male individuals as control. Gene expression profiles of all the cell lines were analysed on an Affymetrix GeneChip 430 2.0 array.
Project description:Phenotypes of haploid embryonic stem cells (haESCs) are dominant for recessive traits in mice. However, one major obstacle to their use is self-diploidization in daily culture. Although haESCs maintain haploidy well by deleting p53, whether they can sustain haploidy in differentiated status and the mechanism behind remain unknown. To address that, we induced p53-deficient haESCs into multiple differentiated lineages keeping a haploid status in vitro. Besides, haploid cells also remained in chimeric embryos and teratomas arising from p53-null haESCs. Transcriptome analysis revealed that apoptosis genes were down-regulated in p53-null haESCs, comparing to that in wild-type haESCs. Finally, we knocked-out p73, another apoptosis gene, and observed stabilization of haploidy in haESCs, either. These results indicated that the main mechanism of diploidization was apoptosis-related genes triggered cell death in haploid cell cultures. Thus, we can derive haploid somatic cells by manipulating apoptosis gene, facilitating genetic screens of lineage-specific development.
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.