500. THE MANIPULATION OF THE EPIGENETIC MARK HISTONE 3 LYSINE 9 TRIMETHYLATION IN DONOR CELLS AND ITS EFFECTS ON THE DEVELOPMENT OF CLONED MOUSE EMBRYOS

2009 ◽  
Vol 21 (9) ◽  
pp. 101
Author(s):  
J. Antony ◽  
F. Oback ◽  
R. Broadhurst ◽  
S. Cole ◽  
C. Graham ◽  
...  

To produce live cloned mammals from adult somatic cells the nuclei of these cells must be first reprogrammed from a very restricted, cell lineage-specific gene expression profile to an embryo-like expression pattern, compatible with embryonic development. Although this has been achieved in a number of species the efficiency of cloning remains very low. Inadequate reprogramming of epigenetic marks in the donor cells correlated with aberrant embryonic gene expression profiles has been identified as a key cause of this inefficiency. Some of the most common epigenetic marks are chemical modifications of histones, the main structural proteins of chromatin. A range of different histone modifications, including acetylation and methylation, exists and can be attributed to either repression or activation of genes. One epigenetic mark which is known to be very stable and difficult to remove during reprogramming is the trimethylation of lysine 9 in histone H3 (H3K9Me3). To test the hypothesis that H3K9Me3 marks are a major stumbling block for successful cloning we are attempting to remove these marks by overexpression of the H3K9Me3 specific histone demethylase, jmjd2b, in donor cells, prior to their use for nuclear transfer. We have engineered mouse embryonic stem (ES) cells for the tet inducible expression of a fusion protein with a functional jmjd2b or non-functional mutant jmjd2b histone demethylase. Approximately 94% and 88% of the cells can be induced for the expression of functional and mutant jmjd2b-EGFP in the respective ES cell lines. Immunofluorescence analyses have shown that induction of functional jmjd2b-EGFP results in an approximately 50% reduction of H3K9Me3 levels compared to non-induced cells and induced mutant jmjd2b-EGFP cells. The comparison of the in-vitro embryo development following nuclear transfer with induced and non-induced donor cells show significantly better overall development to blastocysts and morulae from induced donor cells with reduced H3K9Me3 levels.

2006 ◽  
Vol 18 (2) ◽  
pp. 236
Author(s):  
B. Mohana Kumar ◽  
H.-F. Jin ◽  
J.-G. Kim ◽  
S. Balasubramanian ◽  
S.-Y. Choe ◽  
...  

Abnormal gene expression is frequently observed in nuclear transfer (NT) embryos and is one of the suggested causes of the low success rates of this approach. Recent study has suggested that adult stem cells may be better donor cells for NT, as their less differentiated state may ease epigenetic reprogramming by the oocyte (Kato et al. 2004 Biol. Reprod. 70, 415-418). In the present study, we investigated the expression profile of some selected genes involved in the development of the pre-implantation embryos of in vivo- and NT-derived origin using bone marrow mesenchymal stem cells (MSCs) and porcine fetal fibroblasts (pFF) as donors. Isolated population of MSCs from porcine bone marrow were characterized by cell-surface antigen profile (CD13pos, CD105pos, CD45neg, and CD133neg) and by their extensive consistent differentiation to multiple mesenchymal lineages (adipocytic, osteocytic and chondrocytic) under controlled in vitro conditions (Pittenger et al. 1999 Science 284, 143-147). Primary cultures of pFF from a female fetus at <30 days of gestation were established. for NT, donor cells at 3-4 passages were employed. Embryos cloned from MSCs showed enhanced developmental potential compared to pFF cloned embryos, indicated by higher rates of blastocyst formation (15.3% � 4.8 and 9.0% � 3.9, respectively) and total cell number (31.5 � 7.2 and 20.5 � 5.4, respectively) in Day 7 blastocysts. Total RNA was extracted from pools (triplicates) of 10 embryos each of 8-cell, morula, and blastocyst stages of in vivo and NT origin using Dynabeads� mRNA DIRECT" kit (Dynal, Oslo, Norway). Reverse transcription was performed with a Superscript" III cDNA synthesis kit (Invitrogen, Carlsbad, CA, USA). Real-time PCR was performed on a Light cycler� using FastStart DNA Master SYBR Green I (Roche Diagnostics, Mannheim, Germany). The expression profiles of genes involved in transcription (Oct-4, Stat3), DNA methylation (Dnmt1), de novo methylation (Dnmt3a), histone deacetylation (Hdac2), anti-apoptosis (Bcl-xL), and embryonic growth (Igf2r) were determined. The mRNA of H2a was employed to normalize the levels. Significant differences (P < 0.05) in the relative abundance of Stat3, Dnmt1, Dnmt3a, Bcl2, and Igf2r were observed in pFF NT embryos compared with in vivo-produced embryos, whereas embryos derived from MSCs showed expression patterns similar to those of in vivo-produced embryos. However, Oct-4 and Hdac2 revealed similar expression profiles in NT- and in vivo-produced embryos. These results indicate that MSC-derived NT embryos had enhanced embryonic development and their gene expression pattern more closely resembled that of in vivo-produced embryos. Hence, less differentiated MSCs may have a more flexible potential in improving the efficiency of the porcine NT technique. This work was supported by Grant No. R05-2004-000-10702-0 from KOSEF, Republic of Korea.


Development ◽  
1997 ◽  
Vol 124 (2) ◽  
pp. 279-287 ◽  
Author(s):  
S.A. Duncan ◽  
A. Nagy ◽  
W. Chan

Immediately prior to gastrulation the murine embryo consists of an outer layer of visceral endoderm (VE) and an inner layer of ectoderm. Differentiation and migration of the ectoderm then occurs to produce the three germ layers (ectoderm, embryonic endoderm and mesoderm) from which the fetus is derived. An indication that the VE might have a critical role in this process emerged from studies of Hnf-4(−/−) mouse embryos which fail to undergo normal gastrulation. Since expression of the transcription factor HNF-4 is restricted to the VE during this phase of development, we proposed that HNF-4-regulated gene expression in the VE creates an environment capable of supporting gastrulation. To address this directly we have exploited the versatility of embryonic stem (ES) cells which are amenable to genetic manipulation and can be induced to form VE in vitro. Moreover, embryos derived solely from ES cells can be generated by aggregation with tetraploid morulae. Using Hnf-4(−/−) ES cells we demonstrate that HNF-4 is a key regulator of tissue-specific gene expression in the VE, required for normal expression of secreted factors including alphafetoprotein, apolipoproteins, transthyretin, retinol binding protein, and transferrin. Furthermore, specific complementation of Hnf-4(−/−) embryos with tetraploid-derived Hnf-4(+/+) VE rescues their early developmental arrest, showing conclusively that a functional VE is mandatory for gastrulation.


2011 ◽  
Vol 23 (1) ◽  
pp. 244
Author(s):  
R. Dutta ◽  
D. Malakar ◽  
K. Khate ◽  
J. Akshay

The handmade cloning technique has been a relatively recent addition in the field of nuclear transfer. In the present study, attempts were made to efficiently derive stem cells from handmade cloned (HMC) embryos in goat using adult fibroblast cells, embryonic stem (ES) cells, and lymphocytes as donor cells, and to characterise the derived putative nuclear transfer ES (ntES) cells for their stemness. Efficiency of the donor cells for nuclear transfer was also compared, and an overall cleavage and morula formation rates of 62.44 ± 3.9% and 35.30 ± 3.86%, 75.45 ± 3.92% and 45.84 ± 3.86%, and 56.38 ± 3.92% and 29.09 ± 3.86% were obtained from adult fibroblasts, ES cells, and lymphocytes, respectively. A significant difference was found between ES cells and the other 2 donor cells in terms of cleavage and morula formation. However, no such difference existed between fibroblasts and lymphocyte donor cells. Stem cell colonies were successfully derived from HMC embryos obtained from all 3 different donor cells. The rate of primary colony formation was 61.66 ± 4.62% for fibroblast-donor-cell-derived embryos. This rate was 59.91 ± 4.62% for ES-donor-cell-derived embryos and 62.49 ± 4.62% for lymphocyte-donor-cell-derived embryos. The putative ntES colonies were positively characterised for TRA-1-60, TRA-1-81, SSEA-1, SSEA-4, OCT-4, SOX-2, and Nanog by immunocytochemistry and RT-PCR. Results indicated that ES cells had better efficiency as donor cells in cloned embryo production than did adult fibroblasts and lymphocytes. The finding also suggested that terminally differentiated cell-like lymphocytes can also be reprogrammed. Moreover, there was no difference between the different donor-cell-derived HMC embryos in terms of ntES cell derivation. The study has established an efficient protocol for putative ntES cell derivation from HMC embryos. This could be of substantial significance because patient-specific ntES cells have proven therapeutic significance. The authors acknowledge N.D.R.I for the financial and infrastructural assistance.


2004 ◽  
Vol 16 (2) ◽  
pp. 135
Author(s):  
S.G. Baqir ◽  
Q. Zhou ◽  
A. Jouneau ◽  
J.-P. Renard ◽  
D.H. Betts ◽  
...  

The success rate of producing cloned animals is very low, and in many cases is associated with the formation of enlarged placentas. Increasing evidence has pointed towards epigenetic deregulation of imprinted genes due to incomplete or abnormal resetting of DNA methylation and/or histone acetylation patterns during development. It has previously been shown that drugs that alter DNA methylation (5AzaC) and histone acetylation (TSA) over-express imprinted genes in mouse ES cells (Baqir and Smith, 2001, Theriogenology 55, 410). Our objective in this study was to determine whether nuclear transfer is able to reprogram imprinted gene expression patterns in the placenta of mice cloned from ES donor nuclei exposed to 5AzaC and TSA. ES donor cells were treated with either TSA or 5AzaC prior to injection into enucleated oocytes. Total RNA was extracted from placentas of day 14–15 fetus clones, and reversed transcribed; the expression pattern of imprinted genes (Ipl, Mash2, Igf2, H19, Igf2r, p57, Peg1), non-imprinted placental-specific genes (Esx1, Dlx3, Tpbp) and a housekeeping gene (Gapdh) was examined by Real Time PCR. Samples were standardized with an exogenous control (Globin) and expressed as fold changes in relation to placentas of cloned fetus derived from non-treated donor cells. Data were analyzed by ANOVA and mean gene expression values were compared using the Tukey-Kramer test. Our results show that several imprinted genes (Mash2, H19, Ipl) and placenta-specific genes (Esx1 and Dlx1) were properly reprogrammed in non-enlarged (71mg) placentas of fetus clones derived from the TSA and 5AzaC treated ES donor cells. Although Gapdh expression did not differ among normal and enlarged 210mg) placenta groups, the expression level of Igf2 and Mash2 was higher in enlarged placentas from fetus clones produced from TSA-treated ES donor cells (4.6 and 3.5 fold) compared to non-enlarged placentas from non-treated ES cells (1 fold). Conversely, oversized placentas from cloned fetuses derived from TSA-treated donor ES cells under-expressed Peg1, H19 and Ipl (0.5, 0.2 and 0.2 fold, respectively) compared to control placentas (1 fold). In addition, enlarged placentas from the TSA- and 5AzaC-treated group displayed down-regulation of placenta specific genes Esx1 and Dlx3 and up-regulation of Tpbp, suggesting the presence of abnormal distribution of placental layers. These results indicate that while several imprinted and non-imprinted placenta specific genes were correctly expressed in normal size placentas of fetus clones derived from TSA and 5AzaC treated donor ES cells, enlarged placentas displayed aberrant gene expression patterns, suggesting that improper resetting of the epigenetic program after nuclear transfer is directly related to altered DNA methylation and histone acetylation patterns. Funded by NSERC &amp; CIHR.


Development ◽  
1996 ◽  
Vol 122 (7) ◽  
pp. 2271-2281 ◽  
Author(s):  
H. Weiler-Guettler ◽  
W.C. Aird ◽  
H. Rayburn ◽  
M. Husain ◽  
R.D. Rosenberg

Embryonic lethality of thrombomodulin-deficient mice has indicated an essential role for this regulator of blood coagulation in murine development. Here, the embryonic expression pattern of thrombomodulin was defined by surveying beta-galactosidase activity in a mouse strain in which the reporter gene was placed under the regulatory control of the endogenous thrombomodulin promoter via homologous recombination in embryonic stem cells. The murine trophoblast was identified as a previously unrecognized anatomical site where TM expression is conserved between humans and mice and may exert a critical function during postimplantation development. Targeted reporter gene expression in mesodermal precursors of the endothelial cell lineage defined thrombomodulin as an early marker of vascular differentiation. Analysis of the thrombomodulin promoter in differentiating ES cells and in transgenic mice provided evidence for a disparate and cell type-specific gene regulatory control mechanism in the parietal yolk sac. The thrombomodulin promoter as defined in this study will allow the targeting of gene expression to the parietal yolk sac of transgenic mice and the initiation of investigations into the role of parietal endoderm in placental function.


2007 ◽  
Vol 19 (1) ◽  
pp. 229
Author(s):  
S. Mamo ◽  
J. Kobolak ◽  
S. Becker ◽  
M. Horsch ◽  
J. Beckers ◽  
...  

Molecular phenotyping studies carried out so far on different embryonic stem cells (ESC) have focused mainly on the identification of molecular markers responsible for pluripotency. Unlike these, the goals of our study were to compare and functionally characterize the gene expression profiles of R1 ESC established from F1 (129X1/SvJ � 129S1) blastocysts (Nagy et al. 1993 PNAS 90, 8424–8428) and HM-1 ESC established from an inbred strain (Selfridge et al. 1992 Somat. Cell Mol. Genet. 18, 325–336), as our earlier study showed performance variations between these cells. ES cells were cultured on a mitomycin C-treated mouse embryonic fibroblast feeder cell layer. Cells were grown in standard ES cell medium changed daily [high glucose DMEM (GIBCO-Invitrogen, Carlsbad, CA, USA) supplemented with Na pyruvate (0.11% w/w; GIBCO-Invitrogen), 0.1 mM 2-mercaptoethanol (Sigma-Aldrich, St Louis, MO, USA), fetal bovine serum (15% v/v; HyClone, Logan, UT, USA), 1000 U mL-1 murine-LIF (Chemicon International, Temecula, CA, USA), and antibiotics (penicillin: 50 U mL-1, streptomycin: 50 �g mL-1; Sigma-Aldrich)]. Total RNA was isolated from aliquots of R1 ES cells at passage 13 and HM-1 ES cells at passage 23 using RNeasy Midi kit (Qiagen, D�sseldorf, Germany) procedures. Fifteen �g of total RNA each from the contrasting samples were used for reverse transcription and labeling with either Cy3 or Cy5 dyes (Amersham, Buckinghamshire, UK). The labeled samples were dissolved in hybridization buffer, added to the cDNA arrays (custom produced at GSF) containing over 21 000 sequences, and hybridized for 17 h at 42�C. The microarray results of 4 independent hybridizations were analyzed, and differentially regulated genes were identified. Finally, the results of 4 randomly selected genes were verified by real-time PCR analysis. The analysis revealed 55 transcripts that showed significant variation (P &lt; 0.01) between the 2 ES cell lines. Of these, 8 transcripts were up-regulated and the rest down-regulated in the HM-1 ES cells. Most of these genes were over-represented in important biological processes such as growth and development (21%), cell organization and biogenesis (11%), regulatory roles (21%), and organogenesis (14%). Moreover, the verification analysis using real-time PCR has confirmed the results of microarray. Thus, based on the detailed analysis, and confirmation of the results with independent analysis, it is possible to conclude that the expression profile reflected the true molecular variations between the 2 ES cell lines, and the identified transcripts can serve as molecular markers that explain biological differences between the 2 ES cell lines. This work was supported by EU FP6 (MEXT-CT-2003-509582 and 518240), Wellcome Trust (Grant No.070246), and Hungarian National Science Fund (OTKA T046171).


Zygote ◽  
2011 ◽  
Vol 20 (4) ◽  
pp. 347-352 ◽  
Author(s):  
Guangyun Tan ◽  
Linzhu Ren ◽  
Yongye Huang ◽  
Xiaochun Tang ◽  
Yang Zhou ◽  
...  

SummaryThis study was conducted to establish pig embryonic stem (ES)-like cell lines from nuclear transfer blastocysts. A green fluorescent protein (GFP)-expressing cell line was used as the source of donor cells injected into the enucleated oocytes. Blastocysts were collected at D5 (the fifth day), D7 (the seventh day) and D9 (the ninth day). Differential staining was used to assay the viability and development of blastocysts from the 3 days. The number of inner cell mass (ICM) cells increased from 1.83 ± 0.8 (D5) to 5.37 ± 1.2 (D7) to 7.56 ± 1.5 (D9). The expression profiles of embryonic stem (ES) cell factors (OCT4, SOX2, KLF4 and c-MYC) correlated best with the undifferentiated ES state and were identified by qPCR. The expression of the four factors was increased from D5 to D7, whereas the expression decreased from D7 to D9. We tried to isolate ES-like cells from these embryos. However, ES-like cells from the D7 blastocysts grew slowly and expressed alkaline phosphatase. The cells from the D9 blastocysts grew rapidly but did not express alkaline phosphatase. ES-like cells were not isolated from the D5 blastocysts. These results show that the cells from the D7 embryos are pluripotent but grow slowly. The cells from the D9 embryos grow rapidly but start to lose pluripotency.


2005 ◽  
Vol 25 (6) ◽  
pp. 2475-2485 ◽  
Author(s):  
Takao Kuroda ◽  
Masako Tada ◽  
Hiroshi Kubota ◽  
Hironobu Kimura ◽  
Shin-ya Hatano ◽  
...  

ABSTRACT The pluripotential cell-specific gene Nanog encodes a homeodomain-bearing transcription factor required for maintaining the undifferentiated state of stem cells. However, the molecular mechanisms that regulate Nanog gene expression are largely unknown. To address this important issue, we used luciferase assays to monitor the relative activities of deletion fragments from the 5′-flanking region of the gene. An adjacent pair of highly conserved Octamer- and Sox-binding sites was found to be essential for activating pluripotential state-specific gene expression. Furthermore, the 5′-end fragment encompassing the Octamer/Sox element was sufficient for inducing the proper expression of a green fluorescent protein reporter gene even in human embryonic stem (ES) cells. The potential of OCT4 and SOX2 to bind to this element was verified by electrophoretic mobility shift assays with extracts from F9 embryonal carcinoma cells and embryonic germ cells derived from embryonic day 12.5 embryos. However, in ES cell extracts, a complex of OCT4 with an undefined factor preferentially bound to the Octamer/Sox element. Thus, Nanog transcription may be regulated through an interaction between Oct4 and Sox2 or a novel pluripotential cell-specific Sox element-binding factor which is prominent in ES cells.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jeffrey L. Ebersole ◽  
Radhakrishnan Nagarajan ◽  
Sreenatha Kirakodu ◽  
Octavio A. Gonzalez

AbstractWe used a nonhuman primate model of ligature-induced periodontitis to identify patterns of gingival transcriptomic after changes demarcating phases of periodontitis lesions (initiation, progression, resolution). A total of 18 adult Macaca mulatta (12–22 years) had ligatures placed (premolar, 1st molar teeth) in all 4 quadrants. Gingival tissue samples were obtained (baseline, 2 weeks, 1 and 3 months during periodontitis and at 5 months resolution). Gene expression was analyzed by microarray [Rhesus Gene 1.0 ST Array (Affymetrix)]. Compared to baseline, a large array of genes were significantly altered at initiation (n = 6049), early progression (n = 4893), and late progression (n = 5078) of disease, with the preponderance being up-regulated. Additionally, 1918 genes were altered in expression with disease resolution, skewed towards down-regulation. Assessment of the genes demonstrated specific profiles of epithelial, bone/connective tissue, apoptosis/autophagy, metabolism, regulatory, immune, and inflammatory responses that were related to health, stages of disease, and tissues with resolved lesions. Unique transcriptomic profiles occured during the kinetics of the periodontitis lesion exacerbation and remission. We delineated phase specific gene expression profiles of the disease lesion. Detection of these gene products in gingival crevicular fluid samples from human disease may contribute to a better understanding of the biological dynamics of the disease to improve patient management.


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