53 EVALUATION OF NUCLEAR REPROGRAMMING IN CLONED MINIATURE PIG EMBRYOS USING GENES OF Oct-4 FAMILY

2006 ◽  
Vol 18 (2) ◽  
pp. 135
Author(s):  
E. Lee ◽  
S. H. Lee ◽  
S. Kim ◽  
Y. W. Jeong ◽  
J. H. Kim ◽  
...  
Keyword(s):  
Germ Cell ◽  
Somatic Cell ◽  
Expression Patterns ◽  
Fibroblast Cell ◽  
Marker Genes ◽  
Miniature Pig ◽  
Cell Nuclei ◽  
Cell Clones ◽  
Somatic Cell Nucleus ◽  
Reliable Marker

Xenotransplantation as a source of organs is a rapidly expanding field which can save thousands of human lives each year. Cloned miniature pigs have been considered as a model system for xenotransplantation. However, the efficiency of somatic cell nuclear transfer (SCNT) is extremely low, with most clones resulting in early lethality and several aberrancies. Possible explanation of the developmental failure of SCNT embryos is related to insufficient reprogramming of the somatic cell nucleus. In order to test this, we analyzed the reprogramming capacity of differentiated fibroblast cell nuclei and undifferentiated germ cell nuclei with Oct-4 and four Oct-4-related genes (Ndp5211, Dppa2, Dppa3, and Dppa5) as molecular markers using quantitative reverse transcription-polymerase chain reaction (RT-PCR). Oct-4 expression patterns were similar among IVF-derived embryos and cloned embryos derived from fibroblasts or germ cells during pre-implantation embryo development. However, the expression level was significantly lower (P < 0.05) in hatched blastocysts of fibroblast clones compared to other hatched blastocysts. Also, 9 of 13 cloned morulae and 12 of 40 cloned blastocysts failed to reactivate at least one of the five tested genes, whereas all of the germ cell clones and control embryos correctly expressed these genes. Analysis with miniature pig fetuses collected at Day 30 of gestation revealed that normal and cloned fetuses successfully expressed these genes. In conclusion, our results suggest that analysis of expression of Oct-4 and related genes could be a reliable marker for evaluating the reprogramming status of transplanted donor nuclei in cloned embryos. The reprogramming of fibroblast cloned embryos is highly error-prone. This may contribute to their embryonic lethality because cloned embryos that fail to reactivate the marker genes may fail to be successfully implanted. This study was supported by grants from the Ministry of Science and Technology (Top Scientist Fellowship), and the Biogreen 21-1000520030100000.

scholarly journals Remodeling of mouse thymocyte nuclei depends on the time of their transfer into activated, homologous oocytes

1988 ◽  
Vol 91 (4) ◽  
pp. 603-613
Author(s):  
D. Szollosi ◽  
R. Czolowska ◽  
M.S. Szollosi ◽  
A.K. Tarkowski
Keyword(s):  
Nuclear Envelope ◽  
Somatic Cell ◽  
Morphological Changes ◽  
Factor Activity ◽  
Cell Nuclei ◽  
Nuclear Envelope Breakdown ◽  
Somatic Cell Nucleus ◽  
Short Time ◽  
Nuclear Remodeling ◽  
Maturation Promoting Factor

The potential of parthenogenetically activated mouse oocytes to remodel somatic cell nuclei was studied by ultrastructural means using oocyte-thymocyte hybrids. Complete nuclear remodeling, initiated by nuclear envelope breakdown and chromosome condensation (which is followed by formation of pronucleus-like nucleus) is possible only during a short time gap between metaphase II and telophase of meiotic division. Maturation-promoting factor activity is high during this period. The thymocyte nucleus can follow the sequence of morphological changes only in concert with the development of the native nucleus and only after exposure of the chromatin to the ooplasm. If hybridization is effected with pronucleate oocytes, the thymocyte nucleus retains its interphase character but shows particular modifications in nucleolar morphology (identical to changes observed during reactivation of the nucleolus in stimulated lymphocyte) and in the activity of the nuclear envelope (blebbing). Thus the nucleus not exposed to maturation-promoting factor activity may be influenced by a ‘programme’ specific for oocyte (blebbing) and by a programme inherent in the introduced somatic cell nucleus.

49 INTRA-GENUS CLONED EMBRYOS PRODUCTION AND PREGNANCIES DERIVED FROM LEOPARD CAT NUCLEI AND DOMESTIC CAT ENUCLEATED EGGS

2006 ◽  
Vol 18 (2) ◽  
pp. 133 ◽  
Author(s):  
I. K. Kong ◽  
H. S. Lee ◽  
N. H. Kim ◽  
L. H. Kim ◽  
H. D. Shin ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Nuclear Genome ◽  
Fibroblast Cell ◽  
Domestic Cat ◽  
Developmental Competence ◽  
Cell Nuclei ◽  
Reconstructed Embryos ◽  
Significant Difference ◽  
Leopard Cat

The leopard cat (Prionailurus bengalensis), a member of the felidae family, is currently listed as threatened by the Ministry of Environment in South Korea. In exotic or endangered species, the lack of oocytes and recipients precludes the use of traditional somatic cell nuclear transfer (NT), and an approach such as intragenus NT may be the only alternative for producing embryos and offspring. In the present study, we used the leopard cat (LC) as a somatic cell donor to evaluate the in vivo developmental competence, after transfer into domestic cat recipients, of cloned embryos produced by the fusion of LC fibroblast cell nuclei with domestic cat cytoplasts. A total of 412 enucleated domestic cat oocytes were reconstructed with either male (Treatment A) or female (Treatment B) adult LC fibroblasts. There was no significant difference in fusion rate (60.4 vs. 56.9%) between Treatment A and B. Of the fused couplets, the cleavage and blastocyst developmental rate in Treatment A were greater than those in Treatment B (69.5 vs. 60.9%; 8.3 vs. 7.8%; P < 0.05). In treatment A, in vivo developmental studies at 30-45 days postimplantation demonstrated 4.8% (21/435) of reconstructed embryos (n = 435) had entered into the uterine lining of recipients, but only 1.4% (6/435) formed fetuses. However, all of the reconstructed embryos failed to develop to term (65 days). Microsatellite analyses confirmed that the nuclear genome of the cloned fetuses were LC in origin.

79 PSEUDOPHYSIOLOGICAL TRANSCOMPLEMENTARY ACTIVATION OF GOAT OOCYTES RECEIVING ADULT EAR CUTANEOUS FIBROBLAST CELL NUCLEI

2010 ◽  
Vol 22 (1) ◽  
pp. 198
Author(s):  
M. Skrzyszowska ◽  
M. Samiec
Keyword(s):  
Somatic Cell ◽  
Plasma Membranes ◽  
Dermal Fibroblast ◽  
Fibroblast Cell ◽  
Vero Cells ◽  
Atmospheric Conditions ◽  
Cell Nuclei ◽  
Developmental Potential ◽  
Water Saturated

The aim of the study was to determine the in vitro developmental potential of caprine cloned embryos following pseudophysiological (transcytoplasmic) transcomplementary activation of oocytes reconstructed with ear skin-derived fibroblast cell nuclei. The source of nuclear recipient cells were IVM doe oocytes. The reconstruction of the previously enucleated oocytes (i.e. ooplasts) was performed by microinjection of either the somatic cell-derived karyoplasts or intact whole tiny nuclear donor cells directly into the cytoplasm. The reconstructed oocytes were incubated in Upgraded B2 INRA medium for 30 min to 1 h before their pseudophysiological activation. The activation was achieved by electrofusion of clonal cybrids with the allogeneic cytoplasts isolated from caprine IVF-created zygotes, which led to the formation of triple allocytoplasmic hybrids (allocybrids). These originate from 3 sources: (1) homologous whole nuclear donor fibroblast cells or their karyoplasts; (2) enucleated oocytes (ooplasts), and (3) zygote-derived cytoplasts. Single zygote-descended cytoplasts (the so-called zygoplasts) were inserted into the perivitelline space of previously reconstituted oocytes. The resulting zygoplast-clonal cybrid couplets were subsequently subjected to electrofusion, which was induced by application of a single DC pulse of 2.4 kV cm-1 for 15 μs. The electrofusion of zygoplast and reconstructed oocyte plasma membranes occurred in an isotonic dielectric solution deprived of Ca2+ ions. The transcytoplasmically activated clonal cybrids were cultured in vitro in Upgraded B2 INRA medium for 48 h at 38.5°C in a 100% water-saturated atmosphere of 5% CO2 and 95% air. Afterward, cleaved embryos were co-cultured with Vero cells in medium supplemented with 10% fetal bovine serum for an additional 96 to 144 h up to morula and blastocyst stages under the same thermal and atmospheric conditions. A total of 53/78 (67.9%) oocytes reconstructed with fibroblast cell nuclei were successfully fused with zygoplasts. From among 53 cultured cloned embryos, 34 (64.2%) cleaved. The rates of embryos that reached the morula and blastocyst stages were 21/53 (39.6%) and 11/53 (20.8%), respectively. In conclusion, the relatively high percentages of morulae and blastocysts were noticed among in vitro-cultured caprine cloned embryos produced by the strategy of pseudophysiological transcytoplasmic activation of oocytes reconstructed with adult dermal fibroblast cell nuclei. Therefore, the use of cytoplasmic components originating from zygotes as the stimuli for activation of nuclear-transferred oocytes appeared to be an effective procedure in the generation of goat blastocysts by somatic cell cloning.

scholarly journals Testes of DAZL null sheep lack spermatogonia and maintain normal somatic cells

2019 ◽  
Author(s):  
Zachariah McLean ◽  
Sarah Jane Appleby ◽  
Jingwei Wei ◽  
Russell Grant Snell ◽  
Björn Oback
Keyword(s):  
Germ Cell ◽  
Somatic Cell ◽  
Germ Cells ◽  
Genetic Improvement ◽  
Rna Binding ◽  
Somatic Cells ◽  
Marker Genes ◽  
Specific Marker ◽  
Loss Of Function ◽  
Fetal Fibroblasts

AbstractMultiplying the germline would increase the number of offspring that can be produced from selected animals, accelerating genetic improvement for livestock breeding. This could be achieved by producing multiple chimaeric animals, each carrying a mix of donor and host germ cells in their gonads. However, such chimaeric germlines would produce offspring from both donor and host genotypes, limiting the rate of genetic improvement. To resolve this problem and produce chimaeras with absolute donor germline transmission, we have disrupted the RNA-binding protein DAZL and generated germ cell-deficient host animals. Using Cas9 mediated homology-directed repair (HDR), we introduced a DAZL loss-of-function mutation in male ovine fetal fibroblasts. Following manual single-cell isolation, 4/48 (8.3%) of donor cell strains were homozygously HDR-edited. Sequence-validated strains were used as nuclear donors for somatic cell cloning to generate three lambs, which died at birth. All DAZL-null male neonatal sheep lacked germ cells. Somatic cells within their testes were morphologically intact and expressed normal levels of somatic cell-specific marker genes, indicating that the germ cell niche remained intact. This extends the DAZL-mutant phenotype beyond mice into agriculturally relevant ruminants, providing a pathway for using absolute transmitters in rapid livestock improvement.

89 ZYGOTICALLY ACTIVATED GENES ARE SUPPRESSED IN MOUSE NUCLEAR-TRANSFERRED EMBRYOS

2007 ◽  
Vol 19 (1) ◽  
pp. 162
Author(s):  
T. Suzuki ◽  
N. Minami ◽  
H. Imai
Keyword(s):  
Gene Expression ◽  
Somatic Cell ◽  
Early Stage ◽  
Mammalian Species ◽  
Expression Patterns ◽  
Gene Activation ◽  
Blastocyst Stage ◽  
Success Rates ◽  
Cell Nuclei ◽  
Cell Stage

Mammalian oocytes have the ability to confer totipotency to terminally differentiated somatic cell nuclei. Viable cloned animals have been produced by somatic cell nuclear transfer (NT) into oocytes in many mammalian species including mouse. However, the success rates of the production were quite low in all species. Many studies have measured differences in gene expression between NT and fertilized embryos in relatively advanced stages of development such as pre- and post-natal stages or the blastocyst stage. In the mouse, major zygotic gene activation (ZGA) occurs at the 2-cell stage after fertilization and leads to the transition of gene regulation from maternal control to embryonic control. Suppression of the ZGA by a transcription inhibitor was shown to decrease the viability of embryos, and causes developmental arrest at the 2-cell stage. An abnormal ZGA may therefore affect the viability of NT embryos and cause further abnormalities in later embryonic development. In the present study, we compared gene expression patterns using differential display RT-PCR (DDRT-PCR) between the NT and IVF embryos at the 2-cell stage to detect some abnormalities affecting later development of NT embryos. The developmental rate of NT embryos to blastocysts (32.9%) was significantly lower than that of IVF (92.7%) or PA (92.8%). In addition, the cell numbers of NT embryos at the blastocyst stage (39.5 � 2.6; n = 19) were less than those of IVF (66.8 � 2.1; n = 30) or PA embryos (48.2 � 2.1; n = 30). Using these embryos, we first identified 4 genes that were differentially expressed between NT and IVF embryos at the 2-cell stage. Among the identified genes, Inpp5b and Chst12 were up-regulated, and MuERV-L and Dnaja2 were down-regulated in the NT embryos compared with IVF embryos. Further analysis showed that the expression of zygotically activated genes such as Interferon-γ, Dub-1, Spz1, DD2106, and DD2111 were not properly activated in NT embryos, suggesting that the cellular process involved in the control of the zygotic genome activation is not appropriately regulated. These results indicate that abnormal gene expression has already occurred at the early stage of pre-implantation development as a failure of nuclear reprogramming.

76 DEVELOPMENTAL CAPABILITY OF TRANSGENIC NUCLEAR-TRANSFERRED PIG EMBRYOS PRODUCED USING THE NOVEL METHOD OF PSEUDOPHYSIOLOGICAL ACTIVATION

2010 ◽  
Vol 22 (1) ◽  
pp. 196 ◽  
Author(s):  
M. Samiec ◽  
M. Skrzyszowska ◽  
R. Slomski
Keyword(s):  
Somatic Cell ◽  
Donor Cell ◽  
Fibroblast Cell ◽  
Original Method ◽  
Calcium Oscillations ◽  
Cell Nuclei ◽  
Novel Method ◽  
Transgenic Embryos

The physicochemical stimuli, which are commonly used for artificial activation of porcine nuclear-transferred (NT) oocytes, can affect detrimentally or cytotoxically the clonal cybrids and thereby inhibit the development or decrease the quality of cloned embryos. Therefore, we have recently developed a novel method of pseudophysiological transcomplementary (transcytoplasmic) activation to stimulate the developmental program of porcine oocytes reconstructed by somatic cell nuclear transfer. The mechanism underlying this original technique of activation is transcytoplasmic influx of sperm-derived proteins triggering intracellular calcium oscillations, which is mediated via heterologous (rabbit) zygote-descended cytoplasts. The purpose of our study was to estimate the in vitro developmental competences of porcine transgenic cloned embryos following pseudophysiological activation of oocytes receiving pWAPhGH-GFPBsd gene construct-nucleofected fetal fibroblast cell nuclei. In the cloning procedure, IVM pig oocytes were used as recipient cells for cell nuclei of positively selected transgenic fibroblast cells. The reconstruction of enucleated oocytes was performed by intracytoplasmic injection of either the somatic cell-derived karyoplast or whole tiny nuclear donor cell. The activation of porcine NT oocytes was achieved by electrofusion of them with the xenogeneic cytoplasts isolated from in vivo-derived rabbit zygotes (i.e. with the so-called zygoplasts), which led to the formation of triple xenocytoplasmic hybrids (xenocybrids). The rabbit zygotes had been flushed postmortem from the separated oviducts of superovulated postpubertal female donors 18 to 20 hafter administration of hCG and copulation. Single rabbit zygote-descended cytoplasts were inserted into the perivitelline space of previously reconstructed pig oocytes. The resulting zygoplast-NT oocyte couplets underwent fusion, which was induced by generation of 2 successive DC pulses of 1.2 kV cm-1 for 60 μs. The electrofusion medium consisted of 0.3 M Ca2+-deprived mannitol supplemented with 0.1 mM MgSO4 and 0.2 mg mL-1 fatty-acid-free BSA. The transcytoplasmically activated xenocybrids were cultured in vitro for 6 to 7 days up to morula/blastocyst stages. A total of 183/207 (88.4%) oocytes reconstructed with nucleofected fibroblast cell nuclei were successfully fused with zygoplasts. Out of 183 cultured NT embryos, 138 (75.4%) were cleaved. The rates of transgenic NT embryos that reached the morula and blastocyst stages yielded 106/183 (57.9%) and 65/183 (35.5%), respectively. In conclusion, the original method of pseudophysiological activation of porcine NT oocytes turned out to be relatively efficient, which has been confirmed by the high percentages of pWAPhGH-GFPBsd transgenic embryos developing in vitro to morula and blastocyst stages.

scholarly journals Introduction of Mouse Embryonic Fibroblasts into Early Embryos Causes Reprogramming and (Con)fusion

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 772
Author(s):  
Pierre Savatier
Keyword(s):  
Somatic Cell ◽  
Cell Nuclei ◽  
Mouse Embryonic Fibroblasts ◽  
Embryonic Fibroblasts ◽  
Early Embryos

The reprogramming of somatic cell nuclei to achieve pluripotency is one of the most important biological discoveries of the last few decades [...]

scholarly journals Drosophila CG2469 Encodes a Homolog of Human CTR9 and Is Essential for Development

2016 ◽  
Vol 6 (12) ◽  
pp. 3849-3857 ◽  
Author(s):  
Dhananjay Chaturvedi ◽  
Mayu Inaba ◽  
Shane Scoggin ◽  
Michael Buszczak
Keyword(s):  
Germ Cell ◽  
Sequence Similarity ◽  
Cell Loss ◽  
Germline Stem Cell ◽  
Cell Nuclei ◽  
Transcriptional Initiation ◽  
Histone Locus Bodies ◽  
Paf1 Complex ◽  
Histone Locus ◽  
Drosophila Cells

Abstract Conserved from yeast to humans, the Paf1 complex participates in a number of diverse processes including transcriptional initiation and polyadenylation. This complex typically includes five proteins: Paf1, Rtf1, Cdc73, Leo1, and Ctr9. Previous efforts identified clear Drosophila homologs of Paf1, Rtf1, and Cdc73 based on sequence similarity. Further work showed that these proteins help to regulate gene expression and are required for viability. To date, a Drosophila homolog of Ctr9 has remained uncharacterized. Here, we show that the gene CG2469 encodes a functional Drosophila Ctr9 homolog. Both human and Drosophila Ctr9 localize to the nuclei of Drosophila cells and appear enriched in histone locus bodies. RNAi knockdown of Drosophila Ctr9 results in a germline stem cell loss phenotype marked by defects in the morphology of germ cell nuclei. A molecular null mutation of Drosophila Ctr9 results in lethality and a human cDNA CTR9 transgene rescues this phenotype. Clonal analysis in the ovary using this null allele reveals that loss of Drosophila Ctr9 results in a reduction of global levels of histone H3 trimethylation of lysine 4 (H3K4me3), but does not compromise the maintenance of stem cells in ovaries. Given the differences between the null mutant and RNAi knockdown phenotypes, the germ cell defects caused by RNAi likely result from the combined loss of Drosophila Ctr9 and other unidentified genes. These data provide further evidence that the function of this Paf1 complex component is conserved across species.

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