36 EFFECT OF ACTIVATION METHODS ON DNA SYNTHESIS AND DEVELOPMENT OF CANINE PARTHENOGENETIC EMBRYOS

2014 ◽  
Vol 26 (1) ◽  
pp. 132 ◽  
Author(s):  
H. J. Oh ◽  
M. J. Kim ◽  
G. A. Kim ◽  
Y. K. Jo ◽  
J. Choi ◽  
...  
Keyword(s):  
Dna Synthesis ◽  
Nuclear Transfer ◽  
Combined Treatment ◽  
Calcium Ionophore ◽  
Implantation Rate ◽  
Limb Bud ◽  
Brdu Incorporation ◽  
Significant Difference ◽  
Pronuclear Formation

Artificial activation is an important step for successful somatic cell nuclear transfer. In mammals, different methods of parthenogenesis have been studied to increase the developmental efficiency of cloned embryos. In an attempt to improve the techniques of nuclear transfer in canine species, this study investigated the timing of DNA synthesis and in vivo development of canine parthenotes produced by different activation treatments. For canine parthenotes, in vivo matured oocytes were obtained by flushing (~72 h after ovulation) the oviducts of mixed breed bitches. Denuded oocytes were cultured for 4 min in 10 μM calcium ionophore, and then they were divided into 2 groups: (1) 2DMAP group was cultured for 2 h in 6-DMAP; (2) 4DMAP group was cultured for 4 h in 6-DMAP. The first experiment determined DNA synthesis of parthenotes by 1 h treatment with incorporation and immunofluorescent detection of thymidine analogue 5-bromo-2′-deoxyuridine-5′-triphosphate (BrdU). The primary antibody was mouse anti-BrdU (Sigma, St. Louis, MO, USA), and the secondary antibody was fluorescein (FITC)-conjugated affinity purified goat anti-mouse IgG (Jackson). In order to examine the pronuclear formation and the onset of DNA synthesis in experimental groups, parthenotes derived from 2DMAP and 4DMAP groups were observed by BrdU incorporation at 2, 4, and 12 h post-activation (hpa). Data were analysed using Graph Prism software (GraphPad, San Diego, CA, USa). The next experiment observed in vivo development as follows: parthenotes were surgically transferred to synchronized recipient female dogs. The implantation rate of parthenogenetic fetuses was observed in uterus of recipients on Day 26 of pregnancy. All parthenotes of the 2DMAP group showed BrdU incorporation at 2 hpa, whereas 4DMAP parthenotes showed 96% BrdU incorporation at 2 hpa. Incorporation of BrdU was detected in all parthenotes of both experimental groups after 4 hpa. A total of 98 parthenotes were transferred to 9 surrogate mothers (53 parthenotes into 5 recipients in 2DMAP group and 45 parthenotes into 4 recipients in 4DMAP group). There was no significant difference in pregnancy rate between the 2 groups (2DMAP: 60% v. 4DMAP: 50%), whereas the implantation rates were significantly higher in 2DMAP (24.5%) compared with 4DMAP (4.4%; P < 0.001). The recovered parthenotes were able to develop to the stages of limb-bud formation, but few parthenotes showed the small and degenerating formation. Regardless of treatment group, the implantation site of the fetuses indicated either one side or both of the uterus. In conclusion, the present results demonstrated that the protocols using combined treatment with 10 μM of calcium ionophore (4 min) followed by a 2-h culture with 1.9 mM of DMAP resulted in completing pronuclear formation and enhancing fetal formation. This result could be useful method for improving canine cloned embryos production. This study was supported by IPET (#311062–04–2-SB010), RNL Bio (#550–20130013), RDA (PJ008975022013), and Research Institute for Veterinary Science and Natural Balance.

35 EFFECT OF 6-DIMETHYLAMINOPURINE TREATMENT DURATION ON PRONUCLEAR FORMATION AND IN VIVO DEVELOPMENT OF CANINE CLONED EMBRYO

2015 ◽  
Vol 27 (1) ◽  
pp. 110
Author(s):  
H. J. Oh ◽  
G. A. Kim ◽  
M. J. Kim ◽  
Y. K. Jo ◽  
Y. B. Choi ◽  
...  
Keyword(s):  
Embryo Transfer ◽  
Calcium Ionophore ◽  
Brdu Incorporation ◽  
Surrogate Mothers ◽  
Donor Cells ◽  
Significant Difference ◽  
Implantation Rates ◽  
Artificial Activation ◽  
Pronuclear Formation

Artificial activation is an important step for successful somatic cell nuclear transfer (SCNT). In order to clone animals, diverse methods of activation have been studied to increase the developmental efficiency of cloned embryos. Here, we investigated the pronucleus formation and in vivo development of canine cloned embryos produced by different durations of 1.9 mM 6-dimethylaminopurine (DMAP) treatment. For canine SCNT, in vivo-matured oocytes were enucleated, microinjected into the perivitelline space with donor cells, and fused by electrical stimulation. For activation, the fused couplets were cultured for 4 min in 10 μM calcium ionophore, and then they were divided into 2 groups: (1) the 2DMAP group was cultured for 2 h in DMAP; (2) the 4DMAP group was cultured for 4 h in DMAP. Activated cloned embryos were subjected to 2 analyses: (1) observing the pronuclear formation by bromodeoxyuridine (BrdU) incorporation at 2 h, 4 h and 8 h post-activation (hpa), and (2) following fetus formation and pregnancy efficiency after embryo transfer into naturally synchronous recipients. Pregnancy diagnosis was performed by ultrasonography on Day 26 of embryo transfer. Data were analysed using Graph Prism software (GraphPad Software Inc., San Diego, CA, USA). All cloned embryos of the 2DMAP group showed BrdU incorporation at 2 hpa, whereas 4DMAP embryos showed 77.7% BrdU incorporation at 2 hpa (P < 0.05). Incorporation of BrdU was detected in all cloned embryos of both experimental groups after 4 hpa and 8 hpa. A total of 370 cloned embryos were transferred to 24 surrogate mothers (182 cloned embryos into 12 recipients in 2DMAP group and 188 cloned embryos into 12 recipients in 4DMAP group). There was no significant difference in pregnancy rate (2DMAP; 41.6% v. 4DMAP; 33.3%) or implantation rates (2DMAP; 4.9% v. 4DMAP; 3.7%) between the 2 groups. In conclusion, DMAP exposure for 2 h in activation completed pronucleus development of canine reconstructed embryos. However, none of the applied tested treatments resulted in increased implantation rates. This study was supported by RDA (#PJ008975022014), IPET (#311062–04–3SB010), Research Institute for Veterinary Science, Nestlé Purina PetCare and the BK21 plus program.

scholarly journals 64COMPARISON OF DEVELOPMENTAL POTENTIAL OF IN VIVO AND IN VITRO RECIPIENT OOCYTES AFTER NUCLEAR TRANSFER IN GOAT

2004 ◽  
Vol 16 (2) ◽  
pp. 154
Author(s):  
H.S. Park ◽  
M.Y. Lee ◽  
S.P. Hong ◽  
J.I. Jin ◽  
J.K. Park ◽  
...  
Keyword(s):  
Nuclear Transfer ◽  
Electric Pulse ◽  
Serum Starvation ◽  
Cleavage Rate ◽  
Developmental Potential ◽  
In Vitro Development ◽  
Significant Difference ◽  
Vitro Development

Recent techniques in somatic cell nuclear transfer (SCNT) have been widely used for animal research. In addition, SCNT techniques may allow for the rescue of endangered species. Despite efforts for wildlife preservation, however, some threatened or endangered wild animal species will likely become extinct. As a preliminary experiment of a series in wildlife research, we tried to identify an improved method for the production of more transferable NT embryos in goats. Mature donor animals of Korean native goats (20–25kg) were synchronized with a CIDR (type G; InterAg, New Zealand) vaginal implant for 10 days followed by a total of 8 twice daily injections of 70mg of FSH (Folltropine, London, Ontario, Canada) and 400IU of hCG (Chorulon, Intervet, Moxmeer, The Netherlands). Oocytes were then collected surgically by retograde oviduct flush or direct aspiration from ovarian follicles in vivo at 29–34h after hCG. Oocytes collected from follicles were matured in TCM-199 containing 10% FBS and hormones. Prepared ear skin cells from the goat were cultured in TCM-199 containing 10% FBS at 39°C, 5% CO2 in air, and confluent monolayers were obtained. Oocytes were enucleated and donor cells from serum starvation (0.5%) culture were fused through a single electric pulse (DC 2.36kvcm−1, 17μs), and then activated by a single electric pulse (AC 5vmm−1, 5s+DC 1.56kvcm−1, 30μs) or chemical treatment (5μgmL−1 ionomycin 5min−1, 1.9mM 6-DMAP/4h). Reconstructed oocytes were cultured in M16 medium with 10% goat serum (GS) for 6–7 days. Data were analyzed by chi-square test. In in vitro development, significantly (P&lt;0.05) more oocytes were cleaved (24/30, 80.0%) and developed (7/24, 29.2%) to morula or blastocyst stage, respectively, in NT oocytes activated by Iono + DMAP compared to electric stimulated oocytes (2/21, 40.0%; 0/2, 0%). There was a significant difference in in vitro development of NT embryos by the method of oocyte collection. Cleavage rate was higher (P&lt;0.05) in NT embryos from in vivo oocytes (23/28, 82.1%) than in in vitro matured oocytes (19/35, 54.3%), and further development to morula or blastocyst was also significantly (P&lt;0.05%) higher in NT embryos from in vivo oocytes (7/23, 30.4%) than in NT embryos from in vitro matured oocytes (0/19, 0%). When we compared NT embryos to parthenotes, developmental rate was not significantly different between NT embryos and parthenotes. These results strongly suggest that the in vivo oocytes will have superior developmental potential to oocytes matured in vitro. Table 1 Effect of different oocyte source on in vitro development following caprine SCNT

The impact of nanoplastic on embryonic development of Antarctic krill in current and future acidified conditions of the Southern Ocean 

2021 ◽  
Author(s):  
Emily Rowlands ◽  
Tamara Galloway ◽  
Matthew Cole ◽  
Ceri Lewis ◽  
Victoria Peck ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Southern Ocean ◽  
Antarctic Krill ◽  
Multiple Stressors ◽  
Combined Treatment ◽  
Limb Bud ◽  
Atlantic Sector ◽  
Antarctic Species ◽  
Significant Difference ◽  
The Impact

&lt;p&gt;Antarctic krill (&lt;em&gt;Euphausia superba&lt;/em&gt;), hereafter krill, are pivotal to the Antarctic marine ecosystem, forming the base of a highly productive system and contributing significantly to the biogeochemical cycle. The negative effects of anthropogenic climate stressors amplified in the Southern Ocean such as rapid warming and ocean acidification (OA) have been acknowledged for krill. Less explored is the impact of increasing plastic pollution, particularly in conditions that reflect the likely future Southern Ocean environment. We hypothesise that krill have heightened vulnerability to multi-stressor scenarios due to their physiological and behavioural traits coupled with rapid environmental changes of their Antarctic habitats. Here, we investigate the single and combined effects of nanoplastic (NP; spherical, aminated (NP-NH&lt;sub&gt;2&lt;/sub&gt;), yellow-green, fluorescent polystyrene nanoparticles) and OA (pCO&lt;sub&gt;2&lt;/sub&gt;-manipulated seawater, pH 7.7) on the embryonic development of krill eggs. Krill were collected in the Scotia Sea within the Atlantic sector of the Southern Ocean in austral summer 2019. Eggs from a single female were incubated in seawater at 0.5 &amp;#176;C for 6 days with three treatments: (i) with 0.16 &amp;#956;m NP, (ii) in acidified conditions, and (iii) with a combined treatment of NP (0.16&amp;#956;m) and acidification. All NP treatments were at a concentration of 2.5&amp;#956;g/ml. We found that exposure to the NP-OA multi-stress treatment negatively impacted the development of embryos, decreasing the probability of reaching the limb bud stage by 9% compared with the control, whilst no significant difference was observed for the singular NP or OA treatments. This preliminary study supports our hypothesis regarding the potential impacts of multiple stressors on vulnerable embryonic stages of this ecologically critical Antarctic species.&lt;/p&gt;

24 BUFFALO (BUBALUS BUBALIS) SOMATIC CELL NUCLEAR TRANSFER EMBRYOS PRODUCED FROM FROZEN–THAWED SEMEN-DERIVED SOMATIC CELLS: EFFECT OF TRICHOSTATIN A ON THE IN VITRO AND IN VIVO DEVELOPMENTAL POTENTIAL, QUALITY, AND EPIGENETIC STATUS

2015 ◽  
Vol 27 (1) ◽  
pp. 104
Author(s):  
N. L. Selokar ◽  
M. Saini ◽  
H. Agrawal ◽  
P. Palta ◽  
M. S. Chauhan ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Trichostatin A ◽  
Somatic Cells ◽  
Developmental Potential ◽  
Reconstructed Embryos ◽  
Frozen Semen ◽  
Significant Difference

Cryopreservation of semen allows preservation of somatic cells, which can be used for the production of progeny through somatic cell nuclear transfer (SCNT). This approach could enable restoration of valuable high-genetic-merit progeny-tested bulls, which may be dead but the cryopreserved semen is available. We have successfully produced a live buffalo calf by SCNT using somatic cells isolated from >10 year old frozen semen (Selokar et al. 2014 PLoS One 9, e90755). However, the calf survived only for 12 h, which indicates faulty reprogramming of these cells. The present study was, therefore, carried out to study the effect of treatment with trichostatin A (TSA), an epigenetic modifier, on reprogramming of these cells. Production of cloned embryos and determination of quality and level of epigenetic markers in blastocysts were performed according to the methods described previously (Selokar et al. 2014 PLoS One 9, e90755). To examine the effects of TSA (0, 50, and 75 nM), 10 separate experiments were performed on 125, 175, and 207 reconstructed embryos, respectively. The percentage data were analysed using SYSTAT 12.0 (SPSS Inc., Chicago, IL, USA) after arcsine transformation. Differences between means were analysed by one-way ANOVA followed by Fisher's least significant difference test for significance at P < 0.05. When the reconstructed buffalo embryos produced by hand-made clones were treated with 0, 50, or 75 nM TSA post-electrofusion for 10 h, the cleavage percentage (100.0 ± 0, 94.5 ± 2.3, and 96.1 ± 1.2, respectively) and blastocyst percentage (50.6 ± 2.3, 48.4 ± 2.7, and 48.1 ± 2.6, respectively), total cell number (274.9 ± 17.4, 289.1 ± 30.1, and 317.0 ± 24.2, respectively), and apoptotic index (3.4 ± 0.9, 4.5 ± 1.4, and 5.6 ± 0.7, respectively) in Day 8 blastocysts were not significantly different among different groups. The TSA treatment increased (P < 0.05) the global level of H4K5ac but not that of H3K18a in embryos treated with 50 or 75 nM TSA compared with that in controls. In contrast, the level of H3K27me3 was significantly lower (P < 0.05) in cloned embryos treated with 75 nM TSA than in embryos treated with 50 nM TSA or controls. The ultimate test of the reprogramming potential of any donor cell type is its ability to produce live offspring. To examine the in vivo developmental potential of the 0, 50, or 75 nM TSA treated embryos, we transferred Day 8 blastocysts, 2 each to 5, 6, and 5 recipients, respectively, which resulted in 2 pregnancies from 75 nM TSA treated embryos. However, one pregnancy was aborted in the first trimester and the other in the third trimester. In conclusion, TSA treatment of reconstructed embryos produced from semen-derived somatic cells alters their epigenetic status but does not improve the live birth rate. We are currently optimizing an effective strategy to improve the cloning efficiency of semen-derived somatic cells.

Using epigenetic reprogramming to target triple-negative breast cancer

2009 ◽  
Vol 27 (15_suppl) ◽  
pp. e14565-e14565
Author(s):  
D. Sharma ◽  
B. B. Knight ◽  
R. Yacoub ◽  
T. Liu ◽  
L. Taliaferro-Smith ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cancer Cells ◽  
Breast Cancer Cells ◽  
Hormone Receptors ◽  
Triple Negative ◽  
Combined Treatment ◽  
Brdu Incorporation ◽  
Breast Cancers

e14565 Background: The outcome for patients with breast cancer has been significantly improved by the use of targeted agents. The prognosis of triple negative (TN) breast cancers, which do not express hormone receptors (ER, PR) or Her2, is poor, because of an aggressive clinical course and lack of targeted therapeutic agents. Epigenetic silencing of specific genes has been observed in breast cancer and some of these genes are more important due to available targeted therapies such as ER. Since all endocrine therapies are designed to block ER function in some way, the identification of new therapies or strategies that could sensitize TN breast cancers to existing endocrine therapy could provide a revolutionary means of treating this aggressive subtype of cancer Methods: We examined the efficacy of combined treatment of HDAC inhibitor LBH589 and DNMT inhibitor decitabine to regenerate ER and PR in TN breast cancer cells using RT-PCR and immunoblotting. Changes in growth and proliferation of TN breast cancer cells in response to LBH589 and decitabine treatment were determined by XTT, BrdU incorporation and colony formation assay. Changes in apoptotic proteins were determined by western blotting. Athymic nude mice were used to establish pre-clinical models for TN breast cancer cells and effectiveness of combined treatment of LBH589 and decitabine was determined. Tumors biopsies were analyzed for ER and PR re-expression by western blot analysis and immunohistochemistry at the end of the treatment. Results: Combined treatment of LBH589 and decitabine resulted in re-expression of ER and PR in TN breast cancers in vitro and in vivo. Although re-expression of ER and PR were noted following LBH589 treatment alone, re-expression was more robust with the combination. TN breast cancer cells showing re-expressed ER can be targeted with tamoxifen. Tamoxifen inhibits growth of TN breast cancer cells re- expressing ER by triggering apoptosis. Conclusions: The importance of epigenetic events such as DNA methylation and HDAC inhibition in tumor progression is becoming increasingly evident. A trial evaluating the ability of LBH589 and decitabine to re- express ER, which can then be targeted by tamoxifen, is planned in patients with metastatic TN breast cancer. No significant financial relationships to disclose.

33 PROPAGATION OF ELITE LIFESAVER DOGS BY SOMATIC CELL NUCLEAR TRANSFER

2013 ◽  
Vol 25 (1) ◽  
pp. 164
Author(s):  
B. C. Lee ◽  
H. J. Oh ◽  
M. J. Kim ◽  
G. A. Kim ◽  
E. J. Park ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Culture Media ◽  
Calcium Ionophore ◽  
Defined Medium ◽  
German Shepherd ◽  
Surrogate Mothers ◽  
Working Dogs

Canine somatic cell nuclear transfer (cSCNT) has been used as a useful tool for propagation of elite working dogs. In 2009, 7 cloned dogs were successfully produced using somatic cells derived from the excellent drug-sniffing dog of Korea Customs Service. All cloned dogs perfectly performed drug detection in Incheon International Airport. The objective of the present study was to compare the efficiency of the 2 activation culture media to clone the retired Baekdu, a veteran rescue dog that performed lifesaving activities worldwide for 6 years in Korea National Emergency Management Agency (NEMA). Ear tissue was collected from a 10-year-old male German Shepherd and fibroblasts were cultured for cSCNT. The cells were injected into the perivitelline space of enucleated in vivo-matured dog oocytes, fused with electric stimulation using an electro cell fusion apparatus (Nepa Gene Co. Ltd.), and activated chemically. In the activation protocol, 2 different types of media were tested to investigate the effect of proteins with undefined functions. The first medium was a modified synthetic oviduct fluid (mSOF), which is a complex culture medium with BSA that includes undefined functions. The second medium was the porcine zygote medium (PZM-5), which is a chemically defined medium with polyvinyl alcohol (PVA). The fused couplets were activated by mSOF medium supplemented with 1.9 nM DMAP (SOF-DMAP), and PZM-5 supplemented with 1.9 nM DMAP (PZM-DMAP) for 4 h, followed by 4 min of calcium ionophore treatment. Then, reconstructed oocytes were transferred into the uterine tube of naturally estrus-synchronized surrogate dogs. In the PZM-DMAP group, a total of 56 activated cloned embryos were transferred into 3 female recipient dogs, and a total of 64 activated cloned embryos from the SOF-DMAP group were transferred into 4 female recipients. Pregnancy diagnosis was performed using a SONOACE 9900 (Medison, Seoul, Korea) ultrasound scanner with 7.0-MHz linear-array probe between 30 and 35 days after embryo transfer. As a result, pregnancy was detected in 1 out of 3 surrogate mothers that received cloned embryos from the PZM-DMAP group (33.3%), and 1 pregnancy (25%) was detected in 4 surrogate mothers receiving cloned embryos from the SOF-DMAP group. Two pregnant dogs each gave birth to 1 healthy cloned puppy by cesarean section. This study shows that existence of proteins with undefined functions in activation medium did not affect the dog cloning. In addition, the number of elite working dogs in diverse fields can be increased by the NT technique using donor cells derived from small tissue of elite working dogs. This study was supported by RDA (no. PJ0089752012), RNL Bio (no. 550-20120006), IPET (no. 311062-04-1-SB010), Research Institute for Veterinary Science, and TS Corporation.

scholarly journals The cell cycle–apoptosis connection revisited in the adult brain

2005 ◽  
Vol 171 (4) ◽  
pp. 641-650 ◽  
Author(s):  
Sylvian Bauer ◽  
Paul H. Patterson
Keyword(s):  
Cell Cycle ◽  
Dna Repair ◽  
Dna Synthesis ◽  
Adult Neurogenesis ◽  
Adult Brain ◽  
Brdu Incorporation ◽  
High Dose ◽  
Brdu Labeling ◽  
Postmitotic Neurons

Adult neurogenesis is studied in vivo using thymidine analogues such as bromodeoxyuridine (BrdU) to label DNA synthesis during the S phase of the cell cycle. However, BrdU may also label DNA synthesis events not directly related to cell proliferation, such as DNA repair and/or abortive reentry into the cell cycle, which can occur as part of an apoptotic process in postmitotic neurons. In this study, we used three well-characterized models of injury-induced neuronal apoptosis and the combined visualization of cell birth (BrdU labeling) and death (Tdt-mediated dUTP-biotin nick end labeling) to investigate the specificity of BrdU incorporation in the adult mouse brain in vivo. We present evidence that BrdU is not significantly incorporated during DNA repair and that labeling is not detected in vulnerable or dying postmitotic neurons, even when a high dose of BrdU is directly infused into the brain. These findings have important implications for a controversy surrounding adult neurogenesis: the connection between cell cycle reactivation and apoptosis of terminally differentiated neurons.

scholarly journals 22PRODUCTION OF A CLONED CALF USING KIDNEY CELLS OBTAINED FROM A 48-HOUR COOLED CARCASS

2004 ◽  
Vol 16 (2) ◽  
pp. 133 ◽  
Author(s):  
A.M. Adams ◽  
S.L. Pratt ◽  
J.R. Gibbons ◽  
S. Arat ◽  
D.S. Respess ◽  
...  
Keyword(s):  
Cell Line ◽  
Embryo Development ◽  
Nuclear Transfer ◽  
Calcium Ionophore ◽  
Donor Cell ◽  
Kidney Cells ◽  
Tissue Samples ◽  
Significant Difference ◽  
Beef Heifer ◽  
Beef Carcass

The ability to produce cloned livestock using postmortem tissue could incorporate an additional application into the field of nuclear transfer. This study examined the feasibility of producing cloned cattle using a primary cell line established from a postmortem beef carcass. A market beef heifer processed at a USDA-certified slaughterhouse was used to develop a primary somatic cell line. Tissue samples were taken from the kidney and forelimb regions either 1) immediately following slaughter (fresh) or 2) 48h postslaughter (cooled) where the carcass was housed at 2 to 4°C. Tissue was removed and placed on ice in PBS+5.0% (v:v) penicillin/streptomycin. A primary culture was established using standard techniques and cultured in supplemented DMEM F-12 medium. Once established, cells were trypsinized and either frozen or continually passaged. Cells used for nuclear transfer (NT) were passaged (48h before use) and cultured with 15μM roscovitine roughly 24h prior to nuclear transfer. Cells were approximately 80% confluent and between passage numbers 1 and 11 at the time of NT. Selected slaughterhouse-derived oocytes were matured in supplemented TCM 199 medium for 18–20h at 39°C in 5.0% CO2 and air. Mature Metaphase II oocytes were vortexed and stained with Hoechst 33342 to help with chromatin removal. Following enucleation, roscovitine-treated carcass cells were placed in the perivitelline space of the oocyte. Reconstructed NT embryos were fused in Zimmermann’s medium and pulsed using needle-like electrodes. This was followed by activation using a combination of calcium ionophore (5μM), cytochalasin D (5μgmL−1), and cycloheximide (10μgmL−1) in TCM+10% FBS. Fused NT embryos were cultured in 50-μL drops of BARC medium (USDA, Beltsville, MD) for 7 days at 39°C in a 5% CO2, 5% O2 and 90% N2 environment. Embryo development for all four groups (Table 1) was assessed with blastocysts (grade 1 or 2) being transferred into recipient cows 7 days post-estrus. Cleavage rates were not significantly different between groups, and the use of either fresh or cooled cells did not impact blastocyst formation. However, there was a significant difference (P=0.05) in % blastocyst based on the source of the donor cell. Overall, one live calf resulted from 34 transferred NTs produced using kidney cells taken from a 48h cooled carcass. These results display the feasibility of producing cloned calves from cells collected post mortem, which ultimately could be used as a tool to select breeding bulls based on their own steer carcass characteristics. Table 1 Embryo development and pregnancy data for the production of beef carcass clones

36 DEVELOPMENTAL COMPETENCE OF HUMAN AGED OOCYTES AS HOST CELLS FOR NUCLEAR TRANSFER

2006 ◽  
Vol 18 (2) ◽  
pp. 126
Author(s):  
V. Hall ◽  
D. Compton ◽  
P. Stojkovic ◽  
M. Nesbitt ◽  
M. Herbert ◽  
...  
Keyword(s):  
Nuclear Transfer ◽  
Calcium Ionophore ◽  
Developmental Competence ◽  
Host Cells ◽  
Cell Stage ◽  
Double Labeling ◽  
Immunocytochemical Analysis ◽  
Parthenogenetic Activation

The use of aged metaphase II oocytes (cultured in vitro for more than 14 h) for somatic cell nuclear transfer (SCNT) in varying species has resulted in lower developmental outcomes compared with non-aged in vitro- or in vivo-matured oocytes. However, due to limited resources of fresh oocytes for the derivation of nuclear transfer stem cell lines, further investigation in using spare oocytes is required. Aged spare oocytes (48 h post oocyte retrieval) were consigned for research (under HFEA and local ethics approval) by couples undergoing either in vitro fertilization (failed IVF oocytes, f-IVF) or intracytoplasmic sperm injection (failed-ICSI oocytes, f-ICSI) treatments. Aged oocytes were randomly assigned for double-labeling immunocytochemical analysis (f-IVF, n = 10; f-ICSI, n = 7) for the microtubule markers, NuMA and �-tubulin, or parthenogenetic activation. Immunocytochemical analysis was performed as previously described (Chatzimeletiou et al. 2005 Hum. Reprod. 20, 672-682) using primary anti-rabbit NuMA (gift from D. Compton, Dartmouth Medical School, Hanover, NH, USA) and anti-mouse DM1-�. Secondary antibodies were donkey anti-rabbit and anti-mouse immunoglobulins. Oocytes were counterstained with Hoechst 33342. Negative controls were performed as above with blocking solution substituting for primary antibodies. Parthenogenetic activation was performed for 4 h using 10 �M calcium ionophore (5 min) and 2 mM 6-dimethylaminopurine (Ca-I/DMAP) for f-IVF (n = 10) and f-ICSI oocytes (n = 11) or 10 �g/mL puromycin (Ca-I/Pur) for f-IVF (n = 12) and f-ICSI oocytes (n = 10) (4 h). Activated oocytes were cultured in a biphasic system, G1.3" and G2.3" (Vitrolife UK, Ltd., Ediburgh, Lothian, UK) for 5 days at 37 �C in 5% CO2 in humidified air. NuMA was localized to the metaphase spindle in 6/10 (60%) and 7/7 (100%) oocytes for f-IVF and f-ICSI, respectively, and/or in cytoplasmic cytasters. One f-IVF oocyte and four f-ICSI oocytes had visible tetrapolar spindles. Unusual patterns of diffuse NuMA staining containing dense foci within these regions, but not associated with the cytasters or metaphase spindle, were also observed in two f-IVF oocytes. The majority of oocytes displayed ring-like staining of DM1-�, which was aberrant in two f-ICSI oocytes. Parthenogenetic development was poor for both treatments. Cleavage rates were 17% and 20% for f-IVF using Ca-I/PUR and Ca-I/DMAP, respectively, and 40% and 45% for f-ICSI using Ca-I/PUR and Ca-I/DMAP, respectively. Fragmentation rates were high across all treatments. No parthenogenetic embryos developed beyond the 6-cell stage. Thus, the use of aged human oocytes for SCNT may be difficult due to their incapacity to artificially activate using current activation protocols and, in addition, due to the microtubule abnormalities observed in many of these aged oocytes.

48 TREATMENT OF CLONED BOVINE EMBRYOS WITH HISTONE DEACETYLASE INHIBITORS INCREASES IN VITRO DEVELOPMENT BUT NOT IN VIVO CLONING EFFICIENCY

2009 ◽  
Vol 21 (1) ◽  
pp. 124
Author(s):  
J. E. Oliver ◽  
T. Delaney ◽  
J. N. Oswald ◽  
M. C. Berg ◽  
B. Oback ◽  
...  
Keyword(s):  
Histone Deacetylase ◽  
Nuclear Transfer ◽  
Histone Deacetylase Inhibitors ◽  
Trichostatin A ◽  
Cloning Efficiency ◽  
In Vitro Development ◽  
Significant Difference ◽  
Vitro Development

Previous studies in the mouse have shown treatment of somatic cell nuclear transfer (SCNT) embryos with histone deacetylase inhibitors (HDACi) to significantly increase cloning efficiency (Kishigami S et al. 2006 BBRC 340, 183–189; van Thuan N 2007 Asian Reproductive Biology Society 4, 9 abst). Increasing histone acetylation may open donor chromatin allowing better access for oocyte cytoplasmic factors to facilitate reprogramming. Here, we determined the effect of two HDACi, Trichostatin A (TSA), and scriptaid (Sigma-Aldrich, Castle Hill, NSW, Australia), on bovine cloning efficiency. Zona-free SCNT was performed with serum starved fibroblasts fused to enucleated MII-arrested IVM oocytes. After 4 h, reconstructs were activated with 5 μm ionomycin and 2 mm 6-dimethylaminopurine (DMAP) and cultured individually in 5 μL drops of AgResearch synthetic oviduct fluid (SOF) medium. Treatment with HDACi commenced concomitant with the 4 h DMAP incubation and continued in SOF for the remainder of the treatment period; totalling either 18 or 48 h post activation (hpa). TSA concentrations examined were: 0, 5, 50, and 500 nm, with all treatments containing 0.5% DMSO (n = 1121). Following TSA treatment, increased histone (H) acetylation at lysine (K) of H4K5 was confirmed by semi-quantitative immunofluorescence at the eight-cell stage. Scriptaid concentrations examined were: 0, 5, 50, 250, and 1000 nm, with all treatments containing 0.5% DMSO during DMAP and 0.1% DMSO during IVC (n = 1059). In vitro development on Day 7 was expressed in terms of transferable quality embryos as a percentage of reconstructs cultured. Data were analyzed using a generalized linear model with binomial variation and logit link. Embryos from selected treatments were transferred singularly to recipient cows on Day 7 with pregnancy data analyzed using Fisher’s exact test. Day 7 in vitro development was significantly greater with 5 nm TSA treatment for 18 hpa compared to controls (47.1% v. 34.5%; P < 0.02). Treatment of embryos with TSA for 48 hpa had no effect at any concentration tested. In contrast, scriptaid treatment for 18 hpa had no effect in vitro, while exposure for 48 hpa at 1000 nm significantly increased the development of transferable quality embryos compared to 0 nm (44.0% v. 32.4%; P < 0.005). There was no significant difference in embryo survival rates at D150 of gestation between embryos treated with 0 or 5 nm TSA for 18 hpa (8/48 v. 10/48; 16.7% v. 20.8%). However, in vivo development at Day 150 of gestation following treatment of embryos with 1000 nm scriptaid for 48 hpa was significantly lower compared to controls (1/37 v. 6/31; 2.7% v. 19.4%; P < 0.05). Contrary to the mouse, TSA or scriptaid treatment as used in this study did not increase cloning efficiency in cattle. The use of various HDACi either alone or in combination with DNA demethylating agents may still prove beneficial for reprogramming following nuclear transfer. Supported by FRST C10X0303.

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