scholarly journals Optimized nickase- and nuclease-based prime editing in human and mouse cells

2021 ◽  
Author(s):  
Fatwa Adikusuma ◽  
Caleb Lushington ◽  
Jayshen Arudkumar ◽  
Gelshan I Godahewa ◽  
Yu C.J. Chey ◽  
...  
Keyword(s):  
Cell Lines ◽  
Es Cells ◽  
Embryonic Stem ◽  
Clinical Applications ◽  
Selection Marker ◽  
Mouse Es Cells ◽  
Mammalian Cell Lines ◽  
Mouse Cells ◽  
Mouse Fetuses ◽  
Human And Mouse

Precise genomic modification using prime editing (PE) holds enormous potential for research and clinical applications. Currently, the delivery of PE components to mammalian cell lines requires multiple plasmid vectors. To overcome this limitation, we generated all-in-one prime editing (PEA1) constructs that carry all the components required for PE, along with a selection marker. We tested these constructs (with selection) in HEK293T, K562, HeLa and mouse embryonic stem (ES) cells. We discovered that PE efficiency in HEK293T cells was much higher than previously observed, reaching up to 95% (mean 67%). The efficiency in K562 and HeLa cells, however, remained low. To improve PE efficiency in K562 and HeLa, we generated a nuclease prime editor and tested this system in these cell lines as well as mouse ES cells. PE-nuclease generated intended edits with efficiencies that were similar, and in some cases exceeded, the PE-nickase system. We also show that the nuclease prime editor can generate intended modifications in mouse fetuses with up to 100% efficiency.

Human embryonic stem cells

2000 ◽  
Vol 113 (1) ◽  
pp. 5-10 ◽  
Author(s):  
M.F. Pera ◽  
B. Reubinoff ◽  
A. Trounson
Keyword(s):  
Stem Cells ◽  
Cell Lines ◽  
Embryonal Carcinoma ◽  
Es Cells ◽  
Embryonic Stem ◽  
Early Embryo ◽  
Carcinoma Cells ◽  
Mouse Es Cells ◽  
Undifferentiated State ◽  
Human Es Cells

Embryonic stem (ES) cells are cells derived from the early embryo that can be propagated indefinitely in the primitive undifferentiated state while remaining pluripotent; they share these properties with embryonic germ (EG) cells. Candidate ES and EG cell lines from the human blastocyst and embryonic gonad can differentiate into multiple types of somatic cell. The phenotype of the blastocyst-derived cell lines is very similar to that of monkey ES cells and pluripotent human embryonal carcinoma cells, but differs from that of mouse ES cells or the human germ-cell-derived stem cells. Although our understanding of the control of growth and differentiation of human ES cells is quite limited, it is clear that the development of these cell lines will have a widespread impact on biomedical research.

Embryonic Stem Cells: Prospects for Developmental Biology and Cell Therapy

2005 ◽  
Vol 85 (2) ◽  
pp. 635-678 ◽  
Author(s):  
Anna M. Wobus ◽  
Kenneth R. Boheler
Keyword(s):  
Developmental Biology ◽  
Cell Lines ◽  
Tissue Regeneration ◽  
Es Cells ◽  
Embryonic Stem ◽  
Cell Populations ◽  
Es Cell ◽  
Mouse Es Cells ◽  
Human Es Cells

Stem cells represent natural units of embryonic development and tissue regeneration. Embryonic stem (ES) cells, in particular, possess a nearly unlimited self-renewal capacity and developmental potential to differentiate into virtually any cell type of an organism. Mouse ES cells, which are established as permanent cell lines from early embryos, can be regarded as a versatile biological system that has led to major advances in cell and developmental biology. Human ES cell lines, which have recently been derived, may additionally serve as an unlimited source of cells for regenerative medicine. Before therapeutic applications can be realized, important problems must be resolved. Ethical issues surround the derivation of human ES cells from in vitro fertilized blastocysts. Current techniques for directed differentiation into somatic cell populations remain inefficient and yield heterogeneous cell populations. Transplanted ES cell progeny may not function normally in organs, might retain tumorigenic potential, and could be rejected immunologically. The number of human ES cell lines available for research may also be insufficient to adequately determine their therapeutic potential. Recent molecular and cellular advances with mouse ES cells, however, portend the successful use of these cells in therapeutics. This review therefore focuses both on mouse and human ES cells with respect to in vitro propagation and differentiation as well as their use in basic cell and developmental biology and toxicology and presents prospects for human ES cells in tissue regeneration and transplantation.

Germ line transmission of an inactive N-myc allele generated by homologous recombination in mouse embryonic stem cells

1990 ◽  
Vol 10 (12) ◽  
pp. 6755-6758
Author(s):  
B R Stanton ◽  
S W Reid ◽  
L F Parada
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Homologous Recombination ◽  
Embryonic Development ◽  
Cell Lines ◽  
Germ Line ◽  
Es Cells ◽  
Embryonic Stem ◽  
Es Cell ◽  
Germ Line Transmission

We have disrupted one allele of the N-myc locus in mouse embryonic stem (ES) cells by using homologous recombination techniques and have obtained germ line transmission of null N-myc ES cell lines with transmission of the null N-myc allele to the offspring. The creation of mice with a deficient N-myc allele will allow the generation of offspring bearing null N-myc alleles in both chromosomes and permit study of the role that this proto-oncogene plays in embryonic development.

2. Embryonic stem cells

2021 ◽  
pp. 21-37
Author(s):  
Jonathan Slack
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Inner Cell Mass ◽  
Es Cells ◽  
Practical Importance ◽  
Cell Mass ◽  
Embryonic Stem ◽  
Human Embryos ◽  
Mouse Es Cells ◽  
Stage Embryo

‘Embryonic stem cells’ focuses on embryonic stem (ES) cells, which are grown in tissue culture from the inner cell mass of a mammalian blastocyst-stage embryo. Human ES cells offer a potential route to making the kinds of cells needed for cell therapy. ES cells were originally prepared from mouse embryos. Although somewhat different, cells grown from inner cell masses of human embryos share many properties with mouse ES cells, such as being able to grow without limit and to generate differentiated cell types. Mouse ES cells have so far been of greater practical importance than those of humans because they have enabled a substantial research industry based on the creation of genetically modified mice.

scholarly journals DNA polymerase α interacts with H3-H4 and facilitates the transfer of parental histones to lagging strands

2020 ◽  
Vol 6 (35) ◽  
pp. eabb5820 ◽  
Author(s):  
Zhiming Li ◽  
Xu Hua ◽  
Albert Serra-Cardona ◽  
Xiaowei Xu ◽  
Songlin Gan ◽  
...  
Keyword(s):  
Dna Polymerase ◽  
Es Cells ◽  
Embryonic Stem ◽  
Endogenous Retroviruses ◽  
Histone Binding ◽  
Dna Polymerase Α ◽  
Mouse Es Cells ◽  
Dna Strands ◽  
Histone Deposition

How parental histones, the carriers of epigenetic modifications, are deposited onto replicating DNA remains poorly understood. Here, we describe the eSPAN method (enrichment and sequencing of protein-associated nascent DNA) in mouse embryonic stem (ES) cells and use it to detect histone deposition onto replicating DNA strands with a relatively small number of cells. We show that DNA polymerase α (Pol α), which synthesizes short primers for DNA synthesis, binds histone H3-H4 preferentially. A Pol α mutant defective in histone binding in vitro impairs the transfer of parental H3-H4 to lagging strands in both yeast and mouse ES cells. Last, dysregulation of both coding genes and noncoding endogenous retroviruses is detected in mutant ES cells defective in parental histone transfer. Together, we report an efficient eSPAN method for analysis of DNA replication–linked processes in mouse ES cells and reveal the mechanism of Pol α in parental histone transfer.

scholarly journals Gene Targeting of Cdc42 and Cdc42GAP Affirms the Critical Involvement of Cdc42 in Filopodia Induction, Directed Migration, and Proliferation in Primary Mouse Embryonic Fibroblasts

2006 ◽  
Vol 17 (11) ◽  
pp. 4675-4685 ◽  
Author(s):  
Linda Yang ◽  
Lei Wang ◽  
Yi Zheng
Keyword(s):  
Gene Targeting ◽  
Cell Lines ◽  
Cell Cycle Progression ◽  
Cell Model ◽  
Es Cells ◽  
Embryonic Stem ◽  
Mouse Embryonic Fibroblasts ◽  
Embryonic Fibroblasts ◽  
Membrane Ruffling ◽  
Primary Mouse

Recent studies in Cdc42 knockout mouse embryonic stem (ES) cells and ES-derived fibroblastoid cell lines raise concern on a body of literature derived by dominant mutant expression approach in a variety of cell lines implicating mammalian Cdc42 as a key regulator of filopodia induction, directional migration and cell cycle progression. To resolve the physiological function of mammalian Cdc42, we have characterized the Cdc42−/− and Cdc42GAP−/− primary mouse embryonic fibroblasts (MEFs) produced by gene targeting as the Cdc42 loss- or gain-of-activity cell model. The Cdc42−/− cells were defective in filopodia formation stimulated by bradykinin and in dorsal membrane ruffling stimulated by PDGF, whereas the Cdc42GAP−/− cells displayed spontaneous filopodia. The Cdc42 loss- or gain-of-activity cells were defective in adhesion to fibronectin, wound-healing, polarity establishment, and migration toward a serum gradient. These defects were associated with deficiencies of PAK1, GSK3β, myosin light chain, and FAK phosphorylation. Furthermore, Cdc42−/− cells were defective in G1/S-phase transition and survival, correlating with deficient NF-κB transcription and defective JNK, p70 S6K, and ERK1/2 activation. These results demonstrate a different requirement of Cdc42 activity in primary MEFs from ES or ES-derived clonal fibroblastoid cells and suggest that Cdc42 plays cell-type–specific signaling roles.

scholarly journals Recql5 and Blm RecQ DNA Helicases Have Nonredundant Roles in Suppressing Crossovers

2005 ◽  
Vol 25 (9) ◽  
pp. 3431-3442 ◽  
Author(s):  
Yiduo Hu ◽  
Xincheng Lu ◽  
Ellen Barnes ◽  
Min Yan ◽  
Hua Lou ◽  
...  
Keyword(s):  
Cancer Susceptibility ◽  
Es Cells ◽  
Embryonic Stem ◽  
Bloom Syndrome ◽  
Embryonic Fibroblasts ◽  
Dna Helicases ◽  
Mouse Es Cells ◽  
Elevated Rate ◽  
Wild Type Control ◽  
Mitotic Cells

ABSTRACT In eukaryotes, crossovers in mitotic cells can have deleterious consequences and therefore must be suppressed. Mutations in BLM give rise to Bloom syndrome, a disease that is characterized by an elevated rate of crossovers and increased cancer susceptibility. However, simple eukaryotes such as Saccharomyces cerevisiae have multiple pathways for suppressing crossovers, suggesting that mammals also have multiple pathways for controlling crossovers in their mitotic cells. We show here that in mouse embryonic stem (ES) cells, mutations in either the Bloom syndrome homologue (Blm) or the Recql5 genes result in a significant increase in the frequency of sister chromatid exchange (SCE), whereas deleting both Blm and Recql5 lead to an even higher frequency of SCE. These data indicate that Blm and Recql5 have nonredundant roles in suppressing crossovers in mouse ES cells. Furthermore, we show that mouse embryonic fibroblasts derived from Recql5 knockout mice also exhibit a significantly increased frequency of SCE compared with the corresponding wild-type control. Thus, this study identifies a previously unknown Recql5-dependent, Blm-independent pathway for suppressing crossovers during mitosis in mice.

290 A CYNOMOLGUS MONKEY EMBRYONIC STEM CELL LINE DERIVED FROM A SINGLE BLASTOMERE

2008 ◽  
Vol 20 (1) ◽  
pp. 224
Author(s):  
J. Okahara-Narita ◽  
J. Yamasaki ◽  
C. Iwatani ◽  
H. Tsuchiya ◽  
K. Wakimoto ◽  
...  
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Cynomolgus Monkey ◽  
Es Cells ◽  
Embryonic Stem ◽  
Es Cell ◽  
Cell Stage ◽  
Vitro Assay ◽  
Single Blastomere ◽  
Cell Colony

The establishment of most embryonic stem (ES) cell lines requires the destruction of embryos. Some ES cell lines in mice and humans are currently derived from a single blastomere, so that remaining blastomeres can still develop into fetuses. However, the procedures currently in use for establishing these lines are very complicated, and other ES cell lines from the same species are needed (Chung et al. 2006 Nature 439, 216–219; Klimanskaya et al. 2006 Nature 444, 481–485). The objective of this study was to devise a method simpler than those previously described for establishing ES cell lines from a single blastomere in the cynomolgus monkey. Controlled ovarian stimulation and oocyte recovery have been described previously by Torii et al. (2000 Primates 41, 39–47). Cumulus-free mature oocytes were fertilized by intracytoplasmic sperm injection (ICSI), and then cultured at 38�C in 5% CO2, 5% O2 for 2 days. The zona pellucida of 4- to 5-cell-stage embryos was disrupted using acidic Tyrode's solution, and individual blastomeres were separated from the denuded embryos using trypsin. These blastomeres were cultured on mitomycin-C-treated mouse embryonic fibroblasts and ES medium containing adrenocorticotropic hormone (ACTH) (Ogawa et al. 2004 Genes to Cells 9, 471–477). After the formation of initial outgrowths, half of the medium was changed every other day until the outgrowths reached approximately 100 cells. Passage of putative monkey ES cells was performed by mechanical dispersion of the colonies and transfer to fresh feeders every 3–4 days until there were enough cells for enzymatic dispersion. One stable ES cell line was obtained from two 4- or 5-cell-stage embryos using ES medium containing ACTH. The morphology of this ES cell colony was consistent with the monkey ES cell colony previous described by Suemori et al. (2001 Dev. Dynamics 222, 273–279). The ES cell line was passaged more than 17 times, and the morphology of the ES cell colony did not differ between the first and seventeenth passages. The ES cells showed normal karyotype and retained pluripotency markers for primate ES cells including octamer-binding protein 4 (Oct-4), stage-specific embryonic antigen (SSEA)-4, tumor-rejection antigen (TRA)-1-60, and TRA-1-81. We are presently confirming whether this ES cell line possesses potencies to differentiate in all three embryonic germ layers using both an in vitro assay and teratoma formation. Here we showed that cynomolgus monkey ES cells can be derived from a single blastomere, without co-culturing another ES cell line, as has been done in previous studies on mice and humans. This method allows the establishment of ES cell lines from a single blastomere, leaving the other blastomeres available for embryo transfer. Thus, the method described here is simpler than previously described methods and alleviates some ethical concerns.

287 ACTIVE MITOCHONDRIA ARE PRESENT IN MOUSE AND MONKEY EMBRYONIC STEM CELL LINES

2008 ◽  
Vol 20 (1) ◽  
pp. 223 ◽  
Author(s):  
T. Lonergan ◽  
A. Harvey ◽  
J. Zhao ◽  
B. Bavister ◽  
C. Brenner
Keyword(s):  
Cell Lines ◽  
Complex I ◽  
Inner Cell Mass ◽  
Es Cells ◽  
Cell Mass ◽  
Embryonic Stem ◽  
Mouse Fibroblast ◽  
Es Cell ◽  
Cell Content ◽  
Stem Cell Lines

The inner cell mass (ICM) of the blastocyst develops into the fetus after uterine implantation. Prior to implantation, ICM cells synthesize ATP by glycolytic reactions. We now report that cells of the ICM in 3.5-day-old mouse embryos have too few mitochondria to be visualized with either Mitotracker red (active mitochondria) or an antibody against complex I of OXPHOS. By comparison, all of the surrounding trophectoderm cells reveal numerous mitochondria throughout their cytoplasm. It has largely been assumed that embryonic stem (ES) stem cells derived from the ICM also have few mitochondria, and that replication of mitochondria in the ES cells does not begin until they commence differentiation. We further report that mouse E14 ES cells and monkey ORMES 7 ES cells have considerable numbers of active mitochondria when cultured under standard conditions, i.e., 5% CO2 in air. Both the mouse E14 and monkey ES cell lines expressed two markers of undifferentiated cells, Oct-4 and SSEA-4, and monkey ES cells expressed the undifferentiated cell marker Nanog; however, Oct-4 is nonspecific in monkey ES cells because trophectoderm also expresses this marker, unlike in mice. Ninety-nine percent of the E14 cells examined, and 100% of the ORMES 7 cells, have a visible mitochondrial mass when stained with either Mitoracker red or with an antibody against OXPHOS complex I. The ATP content in the mouse E14 cells (4.13 pmoles ATP/cell) is not significantly different (P = 0.76) from that in a mouse fibroblast control (3.75 pmoles ATP/cell). Cells of the monkey ORMES 7 cell line had 61% of the ATP/cell content (7.55 pmoles ATP/cell) compared to the monkey fibroblast control (12.38 pmoles ATP/cell). Both cell lines expressed two proteins believed to indicate competence of mitochondria to replicate: PolG, the polymerase used to replicate the mitochondrial genome, and TFAM, a nuclear-encoded transcription factor reported to regulate several aspects of mitochondrial function. Both proteins were found to co-localize in the mitochondria. We conclude that when the ICMs are isolated from blastocysts and used to establish these two ES cell lines in cell culture, mitochondrial biosynthesis is activated.

182. NOVEL SIGNALLING IN MOUSE EMBRYONIC STEM CELLS GENERATES PRIMITIVE ECTODERM-LIKE CELLS

2009 ◽  
Vol 21 (9) ◽  
pp. 100
Author(s):  
M. B. Morris ◽  
N. Hamra ◽  
A. C. Lonic ◽  
F. Felquer
Keyword(s):  
Es Cells ◽  
Embryonic Stem ◽  
Cell Types ◽  
Leukaemia Inhibitory Factor ◽  
Signalling Pathways ◽  
Specific Cell ◽  
Self Renewal ◽  
Mouse Es Cells ◽  
Homogeneous Production ◽  
Extracellular Molecules

The phenotypic status of embryonic stem (ES) cells is controlled in part by signalling pathways which translate inputs mediated by extracellular molecules. An important extracellular protagonist in mouse ES cells is LIF (leukaemia inhibitory factor) which interacts with the gp130–LIFR receptor complex to activate a number of downstream signalling pathways, including the STAT3, MEK/ERK and PI3K/Akt. These pathways, together with others, interact in complex and sometimes competing ways to generate the well-known characteristics of mouse ES cells of self-renewal, high rates of proliferation, and pluripotence. The addition of a second molecule, L-proline, to the extracellular environment alters the pluripotent status of mouse ES cells, converting them to a second pluripotent population equivalent to the primitive ectoderm of the pre-gastrulating embryo. This conversion, from ES cells to primitive ectoderm-like cells, primes the latter for directed differentiation to specific cell types (1). Here we show, using inhibitor studies and kinome array analysis, that this small molecule appears to work by (i) changing the balance in activity of signalling pathways already stimulated by LIF and (ii) activating additional signalling pathways. Specifically, L-proline rapidly further activates the LIF-stimulated MEK/ERK pathway, tipping the balance in favour of primitive-ectoderm formation and away from ES-cell self-renewal sustained by LIF-mediated activation of the STAT3 pathway. In addition, L-proline rapidly stimulates other pathways including p38, mTOR and PI3K/Akt each of which contributes, to a greater or lesser extent, to the conversion to primitive ectoderm-like cells. These results indicate that (i) L-proline acts in novel ways to stimulate embryo-like developmental progression in ES cells and (ii) through the addition of small, nontoxic activators and inhibitors of signalling pathways, the differentiation of pluripotent ES cells might be controlled sufficiently well for the homogeneous production of specific cell types suitable for use in animal models of human disease.

Sign in / Sign up

Export Citation Format

Share Document