scholarly journals 72 EFFECT OF CELL CYCLE PHASE OF GENE-MANIPULATED FETAL FIBROBLASTS ON THE DEVELOPMENT OF CLONED BOVINE EMBRYOS

2005 ◽  
Vol 17 (2) ◽  
pp. 186
Author(s):  
M. Urakawa ◽  
T. Sawada ◽  
Y. Sendai ◽  
Y. Shinkai ◽  
A. Ideta ◽  
...  

Transgenic bovine fetuses and offspring can be produced by using gene-modified somatic cells and clones of these cells. In this study, we examined the effects of specific cell cycle (early G1 phase) of donor cell (gene-manipulated fibroblasts) on the development of the nuclear transfer (NT) embryos into blastocysts and on the fetus production after embryo transfer. The gene-manipulated (tg; targeting of one or both alleles of gene encoding α-1,3-galactosyltransferase) or non-manipulated (control) bovine fetal fibroblasts were used for NT. The fibroblasts transfected with the targeting vector were selected with 0.4 mg mL−1 G418. The G418-resistant cells were monitored by PCR and Southern blot analysis. The cells (tg cells) in which homologous recombination occurred were used for NT. For NT, both tg cells and control cells were cultured in DMEM with 10% FCS. Early G1 cells were prepared by choosing pairs of bridged cells derived from mitotic phase cells (Urakawa M et al. 2004 Theriogenology 62, 714–728), and non-synchronized cells were obtained from a culture plate that had reached 60–80% confluence. Each donor cell was inserted into an enucleated, in vitro-matured (19 h) oocyte. Oocyte-cell couples were electrofused and activated with calcium ionophore and cycloheximide. The NT embryos were then co-cultured with bovine oviduct epithelial cells in CR1aa with 5% CS. The blastocyst rates were determined at 6 days after NT. The blastocysts were nonsurgically transferred to recipient heifers, and the developmental rate to the normal fetus was examined by the recovery of fetus or by using ultrasonography at Days 35–42. Data were analyzed by ANOVA. The developmental rate to the blastocyst stage did not differ significantly between tg (28.4%, 128/425) and control (25.4%, 181/739) cell groups. In the control group, the blastocyst rate of embryos constructed from early G1 phase fibroblasts (25.7%, 80/311) was not significantly different from that of embryos constructed with non-synchronized fibroblasts (23.6%, 101/428). In contrast, the blastocyst rate of tg cell derived-embryos was lower (P < 0.05) in early G1 phase (23.5%, 71/302) than in non-synchronized cell phase (46.3%, 57/123). The rate of development to a normal fetus in the tg group (15.4%, 4/26) was significant lower than that in the control group (62.5%, 25/40). For both the tg group and the control group, the rate of development to fetus tended to be higher (P > 0.05) for blastocysts derived from cells at the early G1 phase than for blastocysts derived from non-synchronized cells (tg group, 25.0%, 3/12 v. 7.1%, 1/14; control group, 90.0%, 9/10 v. 53.3%, 16/30). These results demonstrate that gene modification of fetal fibroblasts affects the development of NT embryos to fetuses. In addition, the synchronization of genetically modified donor cells to the early G1 phase may increase the potential to develop to a normal fetus.

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 5377-5377 ◽  
Author(s):  
Mari Cleia Martins Rodrigues Ferreira ◽  
Renata Kikuchi Foltran ◽  
Rodrigo Santucci ◽  
Luis Alberto de Padua Covas Lage ◽  
Debora Levy ◽  
...  

Abstract Introduction: Adult T-cell leukemia/lymphoma (ATLL) is an aggressive and incurable disease caused by human T-lymphotropic virus 1 (HTLV-1) that infects CD4+ and CD8+ lymphocytes, but most commonly the malignant cell present a CD4+ phenotype. However, clonal expansion and cell cycle abnormalities have been demonstrated in CD4+ and in CD8+ lymphocytes of HTLV-1 carriers. Objectives: This study compared DNA content and G0/G1, G2/M and “S”-phases of CD4+ and CD8+ lymphocytes among asymptomatic HTLV-1 carriers, ATLL and health subjects. Methods: Werestudied 38 HTLV-1 carriers, 20 ATLL and 35 health subjects pared by sex and age at the Hematology Department of the Faculty of Medicine, University of São Paulo. Peripheral blood mononuclear cells (PBMCs) were isolated on Ficoll-Paque® and lymphocytes subtypes were obtained by positive selection in a magnetic column. Cell-cycle distribution and DNA index (DI) was assessed by flow cytometry after propidium iodide staining. Results: In ATLL, themedian age was 53.5 years (24 to 72) and 50% were female, in HTLV-1 carriers was 55.5 years (33 to 80) with 63.2% of female and in control group was 50 years (24 to 80) with 54.3% of female. In the CD4+ lymphocyte a % of cells in G0/G1 (98.32%) in HTLV-1 carriers was higher than in control group (97.14%) (p=0.041) and in ATLL (97.25%) (p=0.023). S-phase was not statistically different in asymptomatic carriers (0.34%) and control group (0.63%) (p=0.073), but was higher in ATLL (1.80%) than in asymptomatic carriers (0.34%) (p<0.001) and in control group (0.63%) (p=0.02). G2/M-phase was not significantly different among all groups (p=0.960) (Table 1). The CD4+ lymphocytes were aneuploidy in 39.5% (18.4% DI > 1.05 and 21.5% < 0.95) of asymptomatic carriers and in 26.7% (20% > 1.05 and 6.7% < 0.95) of ATLL patients (p=0.557). All control groups were diploid. Table 1.Comparison of the cell cycle by flow cytometry of T lymphocytes CD4+CD4+ cellsAsymptomatic carriersATLLControl groupp-ValueG0/G1mean(dp)97.78 (2.182)95.69 (3.557)96.55 (2.964)0.0351º; median;3ºq97.03;98.32;99.6491.40;97.25;98.3295.01;97.14;98.64G2/Mmean(dp)1.55(1.848)1.91(2.798)2.03(2.902)0.961º; median;3ºq0.00;0.88;2.670.12;0.99;1.990.00;0.56;2.97S-phasemean(dp)0.68(1.207)2.80(3.372)1.43(1.780)0.0031º; median;3ºq0.00;0.34;0.650.65;1.80;3.510.04;0.63;2.55 In CD8+ there was no found significantly difference in whole groups for G0/G1-phase (p=0.138) and G2/M-phase (p=0.374). ATLL presented higher S-phase (median 1.54%) than asymptomatic carriers (median 0.45%) (p=0.003) and control group. S-phase in asymptomatic carriers was not significantly different in comparison to control group (p=0.712). CD8+ were aneuploidy in 23.7% (5.3% DI > 1.05 and 18.4% < 0.95) of asymptomatic carriers and in 21% (10.5% > 1.05 and 10.5% < 0.95) of ATLL (p=0.603). In ATLL the median of DI was 1.01 (1.0; 1.05) in CD4+ and higher than in CD8+ median 0.99 (0.98; 1.0) (p=0.007). Aneuploidia was seen in 47.7% of ATLL, 26,7% (20% DI > 1.05 and 6,7% < 0.95) in CD4+ and 21,0% in CD8+ (10,5% > 1.05 and10,5% < 0.95) (p=0.625). Figure 1: Dna index of CD4+ and CD8+. Aneuploidia was found in HTLV I carriers in both CD4+ and CD8+. Figure 1:. Dna index of CD4+ and CD8+. Aneuploidia was found in HTLV I carriers in both CD4+ and CD8+. Figure 2. Comparison of DI between CD4+ and CD8+ of asymptomatic carriers and ATLL Figure 2. Comparison of DI between CD4+ and CD8+ of asymptomatic carriers and ATLL Figure 3 Figure 3. Conclusion: We demonstrated for the first time “in vivo” that asymptomatic HTLV-1 carriers display cell cycle arrest in G0/G1-phase in CD4+ lymphocytes and high rate of aneuploidia in both CD4+ and CD8+. ATLL showed high rate of hiperdiploidia in CD4+ and hipodiploidia in CD8+ and high rate of S-phase in CD4+. Genetic instability and proliferative disturbs are a hallmark not only in ATLL but also in HTLV-1 carriers and in both CD4+ and CD8+ lymphocytes. Disclosures No relevant conflicts of interest to declare.


2006 ◽  
Vol 18 (2) ◽  
pp. 250
Author(s):  
M. G. Marques ◽  
A. B. Nascimento ◽  
V. P. Oliveira ◽  
A. R. S. Coutinho ◽  
M. E. O. A. Assumpção ◽  
...  

The present work evaluated the reversible meiosis inhibition effect on the development of swine embryos produced by in vitro fertilization (IVF) or parthenogenetic activation (PA). The efficiency of PZM3 and NCSU23 embryo culture media was also evaluated. Oocytes from ovaries collected at a slaughterhouse were subjected to IVM in two different groups: CHX (cycloheximide 5 µM for 10 h) and control, both with TCM-199 + 3.05 mM glucose + 0.91 mM sodium pyruvate + 10% porcine follicular fluid (pFF) + 0.57 mM cystein + 10 ng epidermal growth factor (EGF)/mL + 10 IU eCG/mL + 10 IU hCG/mL for the initial 22 h. In the remaining period (20 h for CHX and 22 h for control), medium without hormones was utilized. After IVM, oocytes were denuded and fertilized for 6 h (IFV) or the matured oocytes were submitted to activation by electric pulses (PA) (2 DC of 1.5 kV/cm for 30 µs), incubated for 1 h in culture medium with 10 μM of CHX, and again submitted to the same electric pulses for 60 µs. Embryo development was evaluated by cleavage rate on Day 3 and blastocyst rate and blastocyst cell number on Day 7 of culture. Cleavage and blastocyst rates were analyzed by the equality-of-two-ratios test and cell number by the Kruskal-Wallis and Mann-Whitney tests (P < 0.05). In relation to IVF, the PZM3 medium was more efficient than NCSU23 for cleavage rate in the CHX group (PZM3: 68.4%, NCSU23: 44.4%) and had a better blastocyst rate in the control group (PZM3: 13.4%, NCSU23: 5.6%). With reference to PA, NCSU23 presented better cleavage and blastocyst rates than PZM3 in the CHX group (NCSU23: 89.5%, PZM3: 78.5% and NCSU23: 20.4%, PZM3: 13.0%, respectively). In the control group, only the NCSU23 blastocyst rate was higher than that for PZM3 (NCSU23: 22.5%, PZM3: 10.8%). No culture medium effect on cell number mean of IVF and PA blastocysts was observed. Maturation block improved cleavage rates in IVF groups cultured with PZM3 (68.4% and 50.6%, respectively, for CHX and control) and in PA groups cultured with NCSU23 (89.5% and 80.3%, respectively, for CHX and control), but no improvement of blastocyst rates in both groups (IVF and PA) was verified. Table 1 below shows that maturation block decreased the IVF and increased the PA blastocyst cell numbers. As older oocytes are more effectively activated, oocytes blocked with CHX achieved the maturation stage faster than the control group, therefore resulting in high-quality PA blastocysts. In conclusion, PZM3 was more efficient for IVF embryo production in contrast to NCSU23, whereas NCSU23 can be indicated for PA embryo production. Moreover, maturation blockage with CHX influenced blastocyst cell number, decreasing in IVF embryos and increasing in PA embryos. Table 1. Mean (±SD) of blastocyst cell numbers for IVF or PA groups after in vitro maturation without (control) or with cycloheximide (CHX) and cultured in NCSU23 or PZM3 medium This work was supported by FAPESP 02/10747–1.


2007 ◽  
Vol 19 (1) ◽  
pp. 147
Author(s):  
H. T. Lee ◽  
J. M. Jang ◽  
S. H. Lee ◽  
M. K. Gupta

In vitro production of cloned porcine embryos by somatic cell nuclear transfer (SCNT) has become routine in several laboratories but the efficiency and quality of the resultant blastocysts remains sub-optimal. Cloned porcine blastocysts show low cell number, high fragmentation rate, and apoptosis which results in lower pregnancy rates upon embryo transfer. Earlier we reported that supplementation of culture media with amino acids benefit pre-implantation embryo development of in vivo- as well as in vitro-fertilized porcine embryos (Koo et al. 1997 Theriogenology 48, 791–802). This study evaluated how exogenous amino acids could affect pre-implantation development and quality of cloned or parthenogenetic porcine embryos. The effects of commercially available amino acids, referred to as Eagle&apos;s non-essential amino acids (NEAA), added or not added (control) to NCSU23 medium containing fatty acid-free BSA were studied. Oocytes recovered from abattoir-derived prepubertal porcine ovaries were matured in vitro and parthenogenetically activated (PA) or nuclear-transferred with fetal fibroblasts (SCNT), as described earlier (Uhm et al. 2000 Mol. Reprod. Dev. 57, 331–337). At 168 h post-activation, blastocysts were harvested for assessment of embryo quality by TUNEL labeling, Hoechst 33342 staining, and gene expression analysis. Results showed that, in the PA group, the cleavage rate was not affected by the supplementation of NEAA. However, the blastocyst rate was significantly improved when NEAA was present in the medium compared to that of the control group (38.9 &plusmn; 0.3 vs. 27.5 &plusmn; 0.3&percnt;, respectively) throughout the culture period. The supplementation during the pre-compaction period alone gave better results than during the post-compaction period alone (59.5 &plusmn; 0.9 vs. 33.4 &plusmn; 0.3&percnt;, respectively). In the SCNT group, however, both cleavage (73.6 &plusmn; 0.2 vs. 64.2 &plusmn; 0.4&percnt;) and blastocyst rate (18.7 &plusmn; 0.2 vs. 13.8 &plusmn; 0.3&percnt;) were improved by NEAA supplementation. Furthermore, these blastocysts had higher hatching ability (30.0 &plusmn; 1.8 vs. 14.6 &plusmn; 4.9&percnt;) than those of control group (P &lt; 0.05). Supplementation of NEAA also increased the mean nuclei number of PA-derived (76.1 &plusmn; 4.9 vs. 66.5 &plusmn; 3.3) as well as SCNT-derived (43.1 &plusmn; 2.6 vs. 31.8 &plusmn; 1.9) blastocysts and reduced the time during which blastocysts formed. TUNEL assay revealed that incidence of nuclear fragmentation and apotosis was reduced by NEAA. Real-time qRT-PCR for Bax and Bcl-XL transcripts revealed that the relative abundance of Bax was reduced while that of Bcl-XL was increased. These effects were more pronounced when NEAA was present during the pre-compaction period alone. Thus, our data suggest that NEAA improves the yield and quality of cloned porcine embryos by enhancing blastocyst expansion and positively modulating the total cell number and apoptosis. These data may have implications for understanding the nutritional needs of cloned porcine embryos produced in vitro and for optimizing the composition of culture media to support their development. This work was supported by the Research Project on the Production of Bio-Organs (No. 200503030201), Ministry of Agriculture and Forestry, Republic of Korea.


Zygote ◽  
2011 ◽  
Vol 20 (1) ◽  
pp. 61-66 ◽  
Author(s):  
Ying Liu ◽  
Olga Østrup ◽  
Juan Li ◽  
Gábor Vajta ◽  
Lin Lin ◽  
...  

SummaryPre-treating donor cells before somatic cell nuclear transfer (SCNT, ‘cloning’) may improve the efficiency of the technology. The aim of this study was to evaluate the early development of cloned embryos produced with porcine fibroblasts pre-treated with a permeabilizing agent and extract from Xenopus laevis eggs. In Experiment 1, fetal fibroblasts were permeabilized by digitonin, incubated in egg extract and, after re-sealing of cell membranes, cultured for 3 or 5 days before use as donor cells in handmade cloning (HMC). Controls were produced by HMC with non-treated donor cells. The blastocyst rate for reconstructed embryos increased significantly when digitonin-permeabilized, extract-treated cells were used after 5 days of culture after re-sealing. In Experiment 2, fetal and adult fibroblasts were treated with digitonin alone before re-sealing the cell membranes, then cultured for 3 or 5 days and used as donor cells in HMC. Treatment with digitonin alone increased the blastocyst rate, but only when fetal, and not adult fibroblasts, were used as donor cells, and only after 3 days of culture. In conclusion, we find a time window for increased efficiency of porcine SCNT using donor cells after pre-treatment with permeabilization/re-sealing and Xenopus egg extract. Interestingly, we observe a similar increase in cloning efficiency by permeabilization/re-sealing of donor cells without extract treatment that seems to depend on choice of donor cell type. Thus, pre-treatment of donor cells using permeabilizing treatment followed by re-sealing and in vitro culture for few days could be a simple way to improve the efficiency of porcine cloning.


Blood ◽  
2021 ◽  
Vol 138 (Supplement 1) ◽  
pp. 1106-1106
Author(s):  
Rong Fu ◽  
Yingying Chen ◽  
Zonghong Shao ◽  
Hui Liu ◽  
Lijie Zeng ◽  
...  

Abstract Paroxysmal nocturnal hemoglobinuria (PNH) is a disease of hematopoietic stem cell membrane defects due to acquired PIG-Amutation. Our previous study found some secondary gene mutations in PNH patients by WES. However, it is not clear exactly which mutations are associated with the disease. So, 97 target genes were selected as a target gene panel and tested in 23 PNH patients by DNA sequencing of specific target regions. We found that all PNH patients had other gene mutations except PIG-Amutations, including TTN, NCOR2, CPS1, MUC4, SUZ12, LFNG, CELSR2, JAK2, SETBP1 and KMT2D (Figure1A). Through harmful analysis, KEGG enrichment, GO enrichment analysis and protein interaction analysis, we screened out the secondary mutant gene SUZ12 that may be involved in the cloning proliferation of PNH. We detected the mRNA and protein expression levels of SUZ12 and H3K27me3 methylation in PNH patients and health volunteers, the results showed that the mRNA and protein expression levels of SUZ12 and H3K27me3 methylation in peripheral blood CD59 -cells of PNH patients were higher than those in CD59 + cells of PNH patients and healthy controls (Figure1B). The relative expression level of SUZ12 in peripheral blood CD59 -cells of PNH patients was correlated with (r=0.4162, p=0.0385), CD59 -erythrocyte ratio (r=0.4636, p=0.0196), CD59 -monocyte ratio (r=0.4052, p=0.0495), Flaer -monocyte ratio (r=0.6769, p=0.0004) and Flaer -granulocytic ratio (r=0.6146, p=0.0018), indicating that SUZ12 may be involved in abnormal PNH cloning and proliferation by regulating H3K27me3. To verify the role of SUZ12 in the proliferation of PNH cloning, we used CRISPR/Cas9 to knockdown PIG-A expression in THP-1 cells to construct A PNH cell model, the expression level of PIG-A protein in the cell model was significantly decreased, and the proportion of CD59 - cells accounted was stable at 95%. Then lentivirus transfection was used to knockdown the expression of SUZ12 in PNH cell model. The results showed when the SUZ12 expression was knockdown, the methylation level of histone H3K27me3 was decreased, the cell proliferation activity was decreased, apoptosis was increased, and the cell cycle was arrested at G0/G1 phase. The proportion of CD59 + cells increased gradually from 3 weeks after transfection, and significantly increased at 4 weeks after transfection, while no changes were observed in the empty virus group and control group (Figure1C). Four weeks after lentivirus transfection, the expression of PIG-A protein recovered in SUZ12 knockdown group compared with empty virus group and control group (Figure1D). In conclusion, SUZ12 mutation leads to the overexpression of SUZ12, which can affect cell proliferation, apoptosis and cell cycle by regulating the methylation level of histone H3K27me3, thereby promoting the proliferation of PNH abnormal cloning and participating in the pathogenesis of PNH. Figure 1 Figure 1. Disclosures No relevant conflicts of interest to declare.


2015 ◽  
Vol 27 (1) ◽  
pp. 107
Author(s):  
R. Koppang ◽  
N. R. Mtango ◽  
M. Barcelo-Fimbres ◽  
J. P. Verstegen

Porcine somatic cell nuclear transfer (SCNT) is limited to the same or next day surgical embryo transfer due to poor culture conditions in vitro. In this study, we aimed to overcome this problem by treating SCNT embryos with scriptaid, an inhibitor of histone deacetylase (HDACi) that helps with epigenetic reprogramming of the somatic nuclei. Scriptaid was chosen over other HDACi because it has been shown to improve histone acetylation in the same pattern as that of IVF embryos as well as its low toxicity characteristic (Zhao et al. 2009 Biol. Reprod. 81, 525–530; Zhao et al. 2010 Cell Reprogram. 12, 75–78). An inbred miniature pig fetal fibroblast cell line that is known to give low blastocyst rate in culture was used as a source of donor cells transferred into enucleated oocytes. Traditional SCNT was performed; embryos were fused and chemically activated in 10 µM ionomycin for 5 min and 2 mM DMAP for 3 to 4 h before being transferred into scriptaid. Embryos were treated with 500 nM scriptaid (Zhao et al. 2010) for 18 h and the untreated group was used as control. A total of 806 oocytes were used in 8 replicates. The constructed embryos were cultured in modified porcine zygote medium 5 (mPZM-5) for 7 days at 39°C in 5% O2, 5% CO2, 90% N2 atmosphere. Cleavage rates were assessed at 2.5 days and blastocyst rates at Day 7 after activation. Data were analysed by ANOVA using GLM, and percentages were transformed using arcsin square root using Statistix 10 software (Tallahassee, FL, USA). There were no differences in cleavage rates for control group v. scriptaid (55.3 v. 49.9%; P > 0.1; Table 1). The blastocyst rate per construct showed remarkable increase in the scriptaid treated group compared with the control group (12.8 v. 2.2%; P < 0.01; Table 1). Similarly, a significant effect was observed for blastocyst per embryos cleaved where scriptaid had higher rates compared with control (25.8 v. 5.8%; P < 0.01). These results indicated that improving nuclear reprogramming of miniature porcine SCNT clones by scriptaid treatment enhanced blastocyst production during the in vitro culture of porcine embryos. Table 1.Mean (± s.e.m.) measures of embryonic development of SCNT embryos


BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
María I. Pozo ◽  
Benjamin J. Hunt ◽  
Gaby Van Kemenade ◽  
Jose M. Guerra-Sanz ◽  
Felix Wäckers ◽  
...  

Abstract Background Although around 1% of cytosines in bees’ genomes are known to be methylated, less is known about methylation’s effect on bee behavior and fitness. Chemically altered DNA methylation levels have shown clear changes in the dominance and reproductive behavior of workers in queen-less colonies, but the global effect of DNA methylation on caste determination and colony development remains unclear, mainly because of difficulties in controlling for genetic differences among experimental subjects in the parental line. Here, we investigated the effect of the methylation altering agent decitabine on the developmental rate of full bumblebee colonies. Whole genome bisulfite sequencing was used to assess differences in methylation status. Results Our results showed fewer methylated loci in the control group. A total of 22 CpG loci were identified as significantly differentially methylated between treated and control workers with a change in methylation levels of 10% or more. Loci that were methylated differentially between groups participated in pathways including neuron function, oocyte regulation and metabolic processes. Treated colonies tended to develop faster, and therefore more workers were found at a given developmental stage. However, male production followed the opposite trend and it tended to be higher in control colonies. Conclusion Overall, our results indicate that altered methylation patterns resulted in an improved cooperation between workers, while there were no signs of abnormal worker dominance or caste determination.


2007 ◽  
Vol 19 (1) ◽  
pp. 141
Author(s):  
I. S. Hwang ◽  
H. J. Moon ◽  
J. H. Shim ◽  
M. R. Park ◽  
D. H. Kim ◽  
...  

In vitro production of the pig embryo is very important as an initial step to improve its application in biotechnology. The in vitro production system for pig embryos, however, has been plagued by the high incidence of polyspermy and poor embryo quality. The present study was conducted to examine the relationship between apoptosis and osmolarity of culture medium in pre-implantation development of porcine NT and IVF embryos. Oocytes were aspirated from ovaries collected from a local abattoir, and then matured in TCM-199 for 40–44 h. Fresh semen was diluted and equilibrated at 16�C. The final concentration of motile spermatozoa was adjusted to 5 � 105 cells/mL in fertilization medium. Fetal fibroblasts were prepared from a 35-day-old porcine fetus for use as donor cells. The NT and IVF embryos were cultured in PZM-3 supplemented with 0.05 M sucrose or a final concentration of 138 mM NaCl (280–320 mOsmol) for the first 2 days, and then cultured in PZM-3 (250–270 mOsmol) for the remaining days. For the control, NT and IVF embryos were cultured in PZM-3 for whole culture period. After 6 days of culture, the developmental ability of embryos, total cell numbers, ratio of ICM/TE, and apoptosis of cells in blastocysts were examined. The developmental rate to the blastocyst stage of NT embryos was significantly higher (P &lt; 0.05) in the sucrose and NaCl groups than in the control [14.7% (21/153) and 21.7% (34/154) vs. 11.5% (18/152), respectively]. Also, the developmental rate to the blastocyst stage after IVF was slightly higher in embryos cultured in the medium supplemented with NaCl than in the control group [21.8% (49/235) and 26.4% (61/237) vs. 18.9% (44/247)]. For apoptosis, both NT and IVF blastocysts produced in the sucrose and NaCl groups showed slightly lower frequency of apoptosis compared to that of the control (2.2% and 2.8% vs. 3.1% for NT; 0.9% and 0.7% vs. 1.1% for IVF). These studies suggest that the high osmolarity in the early embryo culture stage could enhance the in vitro development of both porcine NT and IVF embryos to the blastocyst stage and could reduce the apoptosis of cells.


2007 ◽  
Vol 19 (1) ◽  
pp. 193
Author(s):  
D. Salilew-Wondim ◽  
F. Rings ◽  
M. Hoelker ◽  
D. Jennen ◽  
E. Tholen ◽  
...  

Selection of developmentally competent oocytes and zygotes based on external morphology has been employed to increase in vitro embryo production. However, this method is more often influenced by personal judgments and lacks universal standards. Hence, this study was aimed at investigating the dielectrophoretic behavior of oocytes and zygotes in relation to their development and mRNA abundance. To achieve the objective, 2 experiments were conducted. In the first experiment, matured bovine oocytes (PB+) and zygotes were subjected to a dielectrophoresis (DEP) procedure designed as follows: 4 MHz AC, 450-�m electrode distance, 5 V, and 80-�s cm-1 medium conductivity. The time elapsed for each of the oocytes and zygotes to reach one of the electrodes from the center was recorded. To accomplish this, 457 PB+ oocytes were subjected to the DEP procedure and 152, 121, 90, and 94 were classified as very fast, fast, slow, and very slow, respectively. Moreover, 152 oocytes were used as controls. Similarly, a total of 940 zygotes were subjected to the DEP procedure and classified as very fast (n = 329), fast (n = 329), slow (n = 97), and very slow (n = 245). In addition, 323 zygotes were used as the control group. The oocyte DEP groups were parthenogenetically activated, and the zygote DEP groups were further in vitro-cultured in a CR1 culture medium supplemented with 10% estrous cow serum, 20 mL mL-1 �-mercaptoethanol, and 10 mL mL-1 minimal essential medium. In PB+ DEP groups, the results show that the blastocyst rate (mean � SEM) at 7 days post-parthenogenetic activation was significantly (P &lt; 0.05) lower in the very slow moving group (7.2 � 4.9) compared to the very fast (21.8 � 3.2), fast (21.5 � 4.6), slow (23.3 � 4.5), and the control (19.7 � 3.7) groups. In zygotes, the blastocyst rate at 7 days post-insemination was significantly (P &lt; 0.05) higher in the very fast (16.1 � 2.7) compared to the slow (9.1 � 2.7) and very slow (10.6 � 2.7) groups, but it was not significantly higher than the fast (12.2 � 2.7) and control (12.3 � 2.7) groups. To investigate whether the transcriptional level of DEP separated very fast and very slow oocytes and zygotes, mRNA expression level was analyzed using a bovine cDNA microarray from a pool of 30 zygotes and oocytes in 6 replications including the dyeswap. The data analyzed using statistical analysis for microarray revealed that 31 and 5 genes were up- and down-regulated, respectively, in very fast compared to very slow PB+ DEP groups. The up-regulated genes are known to be involved in RNA binding and protein biosynthesis (RPL2, RPL8, and RPLPO), ion binding (PTGS2 and ANXA2), and cell cycle regulation (CDC91L1, NUSAP1, and CKS1B). Similarly, 25 and 17 genes were up- and down-regulated, respectively, in the very fast compared to the very slow zygote DEP groups. Some of these genes enriching the very fast zygotes are involved in ion binding (ZNF85, ZNF519, and NANOS1), regulation of cell cycle (NASP, SMARCA5, and AURKA), and signal transduction (RALA). Therefore, from this experiment we can conclude that dielectrophoretically separated oocytes and zygotes show differences in the rate of blastocyst development accompanied by differences in transcriptional abundances.


2010 ◽  
Vol 22 (1) ◽  
pp. 180
Author(s):  
F. F. Bressan ◽  
M. S. Miranda ◽  
F. Perecin ◽  
T. H. C. De Bem ◽  
M. Bajgelman ◽  
...  

Genetically modified animals have numerous applications ranging from basic research to agriculture production. Cloning by nuclear transfer (NT) has made possible the production of transgenic animals using previously genetically modified cell lineages. Gene expression studies and adequate selection of the nuclei donor cell for NT guarantees the presence of the gene construction in the offspring and the absence of deleterious mutations caused by the random insertion of transgenes in functional areas of the genome. Embryonic development after NT requires a change in the transcriptome of the donor cell from a somatic to an embryonic pattern, causing cloning efficiencies to be low because of incomplete or defective nuclear reprogramming. Therefore, the establishment of methodologies able to increase cloning success is highly desirable. The experiment was designed to test if recloning of transgenic fetal fibroblasts increases cloned blastocyst production and the pregnancy rates of transgenic cloned embryos produced by NT. This study compared the developmental potential of cloned embryos reconstructed with fetal fibroblasts genetically modified by lentivirus random integration (control group) expressing the green fluorescent protein gene (eGFP), with a transgenic fetal fibroblast cell line established from a 30-day transgenic pregnancy (recloning group). Fusion, cleavage (72 h post-activation, hpa), blastocyst production (168 hpa), and 30-day pregnancy rates were analyzed. A total of 1213 embryos were reconstructed; 884 (10 replicates) with random transgene insertion fibroblasts and 329 (4 replicates) with cells derived from the cloned fetus. Results were analyzed by chi-square test at 5% significance. No difference was observed (P > 0.05) between control and recloned groups regarding fusion rate (n = 550, 62.22% and n = 189, 57.25%; respectively) or cleavage rate (n = 383, 69.45% and n = 132, 69.84%, respectively). The recloned group, however, showed a higher blastocyst development rate (P < 0.01) compared with the control group (n = 51, 26.98%, and n = 79, 14.36%, respectively) and a higher 30-day pregnancy rate (n = 6, 15.38% and n = 3, 5.56%, respectively). In conclusion, recloning of transgenic fibroblasts from a successfully established pregnancy augments the efficiency in the production of embryos and pregnancy establishment compared with the control group. We speculate that a second round of NT enhances the nuclear reprogramming of donor cells, and moreover, the use of a transgenic cell lineage already proven to be successfully reprogrammed may indicate that transgene integration is not deleterious in that specific cell lineage, resulting in a good source of donor cells to be used in order to produce a homogeneous bioreactor herd. Financial support: FAPESP, Brazil.


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