74 EXAMINATION OF ABNORMAL CELL DIVISION AND CHROMOSOME ABERRATION IN PIG PARTHENOTES AND CLONED EMBRYOS

2006 ◽  
Vol 18 (2) ◽  
pp. 145
Author(s):  
S. J. Uhm ◽  
M. S. Kim ◽  
M. K. Gupta ◽  
H. Y. Lee ◽  
S. J. Park ◽  
...  

Blastomere fragmentation is commonly observed in pig embryos and is associated with reduced blastocyst and pregnancy rates. This study examined the effect of the frequency of abnormal cell division and chromosome aberration on the embryonic developmental ability of pig parthenotes and nuclear transferred (NT) embryos. Pig immature oocytes cultured in TCM-199 supplemented with 10% pig follicular fluid, 0.2 mM pyruvate, 10 ng/mL epidermal growth factor (EGF), 5 �g/mL Folltropin V, 1 �g/mL estradiol-17�, and 25 �g/mL gentamycin for 44 h. Cumulus cells from matured oocytes were removed by vortexing for 1 min in TL-HEPES medium containing 0.1% hyarunonidase. Denuded oocytes were enucleated using 20 um micropipette in TCM-HEPES medium containing 7.5 �g/mL cytochalasin B (CB) and 10% fetal bovine serum, and were reconstructed with fetal fibroblasts by electrofusion (two DC pulses of 2.0 kV/cm for 30 �s). For production of parthenotes and reconstructed embryos, denuded oocytes were activated by a DC pulse of 1.0 kV/cm for 30 �s and then cultured for 4 h in NCSU23 with 10 �g/mL CB and 0.4% bovine serum albumin for inhibition of polar body extrusion. Subsequently, these oocytes were cultured in 50 �L of NCSU23 containing 0.4% BSA for 7 days at 39�C in a humidified atmosphere of 5% CO2 in air. The frequency of chromosome aberrations was evaluated using fluorescent in situ hybridization technique with a porcine chromosome-1 submetacentric specific probe. Data were analyzed by Student's t-test and ANOVA using SAS software as appropriate (SAS Institute, Inc., Cary, NC, USA). Parthenotes and NT embryos showed similiar cleavage rates (61.4 and 62.9%), but the blastocyst rate of parthenotes (18.4%) was significantly higher (P < 0.05) than that of NT embryos (10.4%). The frequency of chromosome aberration in NT embryos (39.8%) at the 4-cell stage on Day 3 of culture was significantly higher (P < 0.05) than that of parthenotes (21.9%). The percentage of fragmentation was significantly higher (P < 0.05) in NT embryos (51.7%) than in parthenotes (27.1%). Furthermore, the developmental rates of non-fragmented parthenotes (40.0%) and NT (22.9%) embryos to the blastocyst stage were significantly higher (P < 0.05) than those of fragmented parthenote and NT embryos (17.3 and 5.9% respectively). The total cell number of non-fragmented parthenote and NT embryos (34.4 � 10.0 and 29.7 � 7.5) were significantly higher (P < 0.05) than those of fragmented parthnote and NT embryos (22.3 � 9.6 and 18.4 � 6.2 respectively). Therefore, these results indicate that chromosomal abnormality and embryonic fragmentation could be associated with reduced developmental ability in pig NT embryos. This work was supported by the Research Project on the Production of Bio-organs, Ministry of Agriculture and Forestry, Republic of Korea.

2005 ◽  
Vol 17 (2) ◽  
pp. 166
Author(s):  
S.K. Cho ◽  
M.R. Park ◽  
D.N. Kwon ◽  
E.K. Lee ◽  
S.J. Kang ◽  
...  

The present study was conducted to investigate the developmental competence of male and female somatic cell derived nuclear transfer (NT) porcine embryos and also the production and survival efficiency of cloned male and female piglets. Maturation of porcine COCs was accomplished by incubation in NCSU-23 medium supplemented with 0.6 mM cysteine, 10% porcine follicular fluid, 1 mM dibutyryl cyclic adenosine monophosphate, and 0.1 IU/mL human menopausal gonadotrophin for 20 h and then culture without dbcAMP and hMG for another 18 to 24 h. Fetal cells were isolated from a male fetus and two female fetuses, and cultured in ES-DMEM medium containing 10% FCS. Enucleated oocytes were fused with fetal fibroblasts (passage 4 to 15). Reconstructed embryos were cultured in NCSU-23 with 4 mg/mL BSA under mineral oil at 39°C in 5% CO2 in air for up to 6 days. NT eggs that had been activated with electric pulses and cultured for 1 or 2 days were transported to the experimental station in modified NCSU-23 with antibiotics. NT embryos were surgically transferred into the oviducts of recipients between Day 27 and Day 30; pregnancy was determined by ultrasound. The potential of NT embryos to develop into blastocysts was not different among donor cells of different origins. However, the mean cell number of in vivo female and male blastocysts (83.8 ± 46.2 to 99.2 ± 55.7) was higher than in in vitro culture of NT groups (31.4 ± 8.29 to 33.2 ± 10.15). A total of 11,535 NT embryos (1- to 8-cell stage) were surgically transferred into 66 surrogate gilts. Among fourteen pregnant gilts, four recipients aborted during the period of conception. Five pregnant gilts delivered fifteen female piglets, 1.28 ± 0.33 kg (0.48∼1.83 kg) in female piglets and 0.84±0.25 kg (0.45∼1.25 kg) in male piglets. Nine live cloned female (60.0%) and four male piglets (18.2%) were produced. According to these results, survival rates and birth weights of female cloned piglets were higher than those of cloned male piglets (P < 0.05). This study suggests that use of female, compared with male, fetal fibroblast cells as nuclear donors may increase cloning outcomes. This work was supported in part by a grant program from RDA(Biogreen21) and Cho-A, Republic of Korea.


2013 ◽  
Vol 25 (1) ◽  
pp. 162 ◽  
Author(s):  
J. Hall ◽  
Q. Meng ◽  
B. R. Sessions ◽  
Z. Fan ◽  
X. Wang ◽  
...  

The yield of blastocysts and hatched blastocysts using in vitro production (IVP) in goats are still low. The development of caprine embryos is frequently arrested at the 8- to 16-cell stage, indicating suboptimal culture conditions (Jimenez-Macedo et al. 2005 Theriogenology 64, 1249–1262). Our goal was to produce transgenic goats by somatic cell nuclear transfer (SCNT) and further determine whether the length of embryo culture has an effect on development to term. We compared the efficiency of transferring single-cell embryos 12 h post-activation to transferring 4- to 8-cell embryos cultured for 60 h post-activation. Nine transgenic goats from 2 cell lines were produced through SCNT. Somatic donor cells were obtained from 2 sources: adult fibroblasts and fetal fibroblasts. Adult fibroblasts were obtained from a transgenic doe skin biopsy. Fetal fibroblasts were isolated from a 25-day-old fetus and then electroporated with a pcDNA3.1DV5-MHC-TGF-β1cys33ser vector, followed by G418 selection, screening, and subsequent use for SCNT. Oocytes with >4 layers of cumulus cells were collected by slicing abattoir ovaries and matured in vitro for 21 to 23 h. After being denuded, oocytes presenting a first polar body were enucleated and received a donor cell from 1 of the 2 cell lines. Fused embryos were then activated for 5 min in 5 µM ionomycin, followed by 4 h in 2 mM DMAP with 5 µg of cycloheximide mL–1. Activated embryos were cultured in G1 medium with 5 mg of BSA mL–1 for either 12 or 60 h post-activation, followed by surgical transfer into the oviducts of recipients synchronized to show estrus within 12 h of SCNT. Overall, 376 embryos were transferred into 23 recipients. Pregnancy was examined by ultrasonography on Day 30 post-transfer. No pregnancy losses were observed after Day 30 of gestation. All kids were born live (42% of recipients receiving embryos cultured for 12 h gave birth, compared with only 9% when cultured for 60 h). The data (Table 1) suggest that a longer culture time in vitro significantly reduces viability of cloned embryos. Table 1.Twelve-hour versus 60-h embryo culture This work was supported by Utah Agricultural Experiment Station project no. 1100.


Development ◽  
1976 ◽  
Vol 35 (1) ◽  
pp. 169-178
Author(s):  
D. R. Pollard ◽  
M. M. Baran ◽  
R. B. Bachvarova

Mouse embryos exposed to concentrations of 5-bromodeoxyuridine (BUdR) ranging from 0·01 to 1·0 μg/ml in vitro for two days from the 8-cell stage exhibit a concentration-dependent decrease in the frequency of normal blastocysts and a decrease in average cell number per embryo. A 20-h exposure was adequate to achieve the full BUdR response. Both effects were eliminated in the presence of excess thymidine. Autoradiographs demonstrated that BUdR[3H] was incorporated into DNA during the first and second day of culture. Thus, BUdR appears to act through incorporation into DNA; and, in this system, cell division is at least as sensitive to BUdR as is differentiation.


2004 ◽  
Vol 16 (2) ◽  
pp. 290
Author(s):  
S.L. Lee ◽  
S.Y. Choe ◽  
G.J. Rho

The overall success rate achieved by cloning techniques to date is low, mainly due to deficiencies in nuclear reprogramming, gene expression and DNA fragmentation, which result in early and late embryonic losses. This study was carried out to compare the incidences of DNA fragmentation during development of IVF, parthenote (PT), nuclear transfer (NT) and transgenic-cloned (TG) embryos. Terminal deoxynucleotidyl transferase (TdT) nick-end labelling (TUNEL) with propidium iodide counterstaining was used for determination of DNA fragmentation and total cell number. Donor cells were fetal fibroblasts with or without transfection with EGFP, and cultured in DMEM+15% FCS until confluent, for up to 5 days. At 19h post maturation (hpm), enucleated oocytes were reconstructed with donor cells and activated at 24hpm with the combination of ionomycin (5μM, 5min) and cycloheximide (10μg/mL, 5h) after electric fusion by a single DC pulse (1.6KV/cm, 60μs) delivered by a BTX 200. Parthenotes were produced by the same activation protocol at 24hpm. The eggs and control IVF embryos were cultured in CR1aa at 39°C in a humidified atmosphere of 5% CO2 in air. Differences among groups were analyzed using one-way ANOVA after arc-sine transformation of proportional data. Embryos at the 8-cell stage in all treatments, IVF, PT, NT and TG, showed DNA fragmentation. The apoptotic cell index (total number of apoptotic nuclei/total number of nuclei) of Day 7 blastocysts was significantly (P&lt;0.05) higher in TG and NT embryos (17/91, 18.6±4.0% and 13/94, 13.8±4.7%, respectively) compared to IVF and PT embryos (9/122, 7.4±3.4% and 8/93, 8.6±2.9%, respectively). TUNEL positive cells were detected in almost all blastocysts at Day 7 and were mainly observed in the ICM. The DNA fragmentation ratio of the ICM in the blastosysts at Day 7 (number of apoptotic nuclei in the ICM/total number of apoptotic nuclei in the blastocyst) was significantly (P&lt;0.05) higher in TG embryos (64.7±21.4%) than in IVF (44.4±28.0%), PT (50.0±18.6%) or NT (53.0±32.5%) embryos. These results indicate a higher occurrence of DNA fragmentation observed in NT and TG embryos when compared to IVF and PT embryos. In addition, ICM of TG blastocysts revealed a high DNA fragmentation ratio, which may be related to early embryonic loss after transfer of the resulting embryos. [Supported by High Technology Development Project for Agriculture and Forestry Korea, MAF-SGRP, 300012-05-3-SB010 and Cho-A Pharm. Co. LTD.]


2021 ◽  
Vol 22 (11) ◽  
pp. 5739
Author(s):  
Joo Yeol Kim ◽  
Hyo-Jun Lee ◽  
Jin A Kim ◽  
Mi-Jeong Jeong

Sound waves affect plants at the biochemical, physical, and genetic levels. However, the mechanisms by which plants respond to sound waves are largely unknown. Therefore, the aim of this study was to examine the effect of sound waves on Arabidopsis thaliana growth. The results of the study showed that Arabidopsis seeds exposed to sound waves (100 and 100 + 9k Hz) for 15 h per day for 3 day had significantly longer root growth than that in the control group. The root length and cell number in the root apical meristem were significantly affected by sound waves. Furthermore, genes involved in cell division were upregulated in seedlings exposed to sound waves. Root development was affected by the concentration and activity of some phytohormones, including cytokinin and auxin. Analysis of the expression levels of genes regulating cytokinin and auxin biosynthesis and signaling showed that cytokinin and ethylene signaling genes were downregulated, while auxin signaling and biosynthesis genes were upregulated in Arabidopsis exposed to sound waves. Additionally, the cytokinin and auxin concentrations of the roots of Arabidopsis plants increased and decreased, respectively, after exposure to sound waves. Our findings suggest that sound waves are potential agricultural tools for improving crop growth performance.


Reproduction ◽  
2006 ◽  
Vol 131 (1) ◽  
pp. 53-61 ◽  
Author(s):  
Mark G Larman ◽  
Courtney B Sheehan ◽  
David K Gardner

Despite the success of embryo cyropreservation, routine oocyte freezing has proved elusive with only around 200 children born since the first reported birth in 1986. The reason for the poor efficiency is unclear, but evidence of zona pellucida hardening following oocyte freezing indicates that current protocols affect oocyte physiology. Here we report that two cryoprotectants commonly used in vitrification procedures, dimethyl sulfoxide (DMSO) and ethylene glycol, cause a large transient increase in intracellular calcium concentration in mouse metaphase II (MII) oocytes comparable to the initial increase triggered at fertilization. Removal of extracellular calcium from the medium failed to affect the response exacted by DMSO challenge, but significantly reduced the ethylene glycol-induced calcium increase. These results suggest that the source of the DMSO-induced calcium increase is solely from the internal calcium pool, as opposed to ethylene glycol that causes an influx of calcium across the plasma membrane from the external medium. By carrying out vitrification in calcium-free media, it was found that zona hardening is significantly reduced and subsequent fertilization and development to the two-cell stage significantly increased. Furthermore, such calcium-free treatment appears not to affect the embryo adversely, as shown by development rates to the blastocyst stage and cell number/allocation. Since zona hardening is one of the early activation events normally triggered by the sperm-induced calcium increases observed at fertilization, it is possible that other processes are negatively affected by the calcium rise caused by cryoprotectants used during oocyte freezing, which might explain the current poor efficiency of this technique.


1996 ◽  
Vol 183 (3) ◽  
pp. 1141-1150 ◽  
Author(s):  
C E Müller-Sieburg ◽  
R Riblet

The genetic elements that govern the differentiation and proliferation of hematopoietic stem cells remain to be defined. We describe here marked strain-specific differences in the frequency of long-term culture-initiating cells (LTC-IC) in the bone marrow of different strains of mice. Mice of C57Bl/6 background showed the lowest levels of stem cells in marrow, averaging 2.4 +/- .06 LTC-IC/10(5) cells, BALB/c is intermediate (9.1 +/- 4.2/10(5) cells), and DBA/2 mice contained a 11-fold higher frequency of LTC-IC (28.1 +/- 16.5/10(5) cells) than C57Bl/6 mice. The genetic factors affecting the size of the stem cell pool were analyzed in the C57Bl/6 X DBA/2 recombinant inbred strains; LTC-IC frequencies ranged widely, indicating that stem cell frequencies are controlled by multiple genes. Quantitative trait linkage analysis suggested that two loci that have major quantitative effects are located on chromosome 1 near Adprp and Acrg, respectively. The mapping of the locus near Adprp was confirmed by finding an elevated stem cell frequency in B6.C-H25, a C57Bl/6 congenic strain that carries a portion of chromosome 1 derived from BALB/c mice. We have named this gene Scfr1 (stem cell frequency regulator 1). The allelic forms of this gene may be an important predictor of stem cell number and thus would be useful for evaluating cell sources in clinical stem cell transplantation.


Development ◽  
1978 ◽  
Vol 48 (1) ◽  
pp. 37-51
Author(s):  
S. J. Kelly ◽  
J. G. Mulnard ◽  
C. F. Graham

Cell division was observed in intact and dissociated mouse embryos between the 2-cell stage and the blastocyst in embryos developing in culture. Division to the 4-cell stage was usually asynchronous. The first cell to divide to the 4-cell stage produced descendants which tended to divide ahead of those cells produced by its slow partner at all subsequent stages of development up to the blastocyte stage. The descendants of the first cell to divide to the 4-cell stage did not subsequently have short cell cycles. The first cell or last cell to divide from the 4-cell stage was labelled with tritiated thymidine. The embryo was reassembled, and it was found that the first pair of cells to reach the 8-cell stage contributed disproportionately more descendants to the ICM when compared with the last cell to divide to the 8-cell stage.


Development ◽  
1975 ◽  
Vol 34 (3) ◽  
pp. 645-655
Author(s):  
Matthew H. Kaufman ◽  
Leo Sachs

The early development of parthenogenetically activated oocytes has been studied in C57BL × CBA-T6T6 (F1T6) translocation heterozygote mice and C57BL × CBA-LAC (F1LAC) mice. All F1T6 oocytes had either a quadrivalent or a univalent-trivalent configuration at meiosis I; no such chromosome configurations were observed in the F1LAC oocytes. At ovulation 36·5 % of the F1T6 oocytes had 19 or 21 chromosomes, whereas 97 % of the F1LAC had the normal haploid chromosome number of 20. After parthenogenetic activation, chromosome counts at metaphase of the first cleavage mitosis were made of the eggs with a single pronucleus following extrusion of the second polar body. These activated eggs had similar frequencies of 19, 20 and 21 chromosomes as had the oocytes at ovulation. The activated 1-cell eggs were transferred to the oviducts of pseudopregnant recipients and the embryos recovered 3 days later. At this stage of development, most of the F1T6 embryos with 19 chromosomes were no longer found, but the frequency of 21-chromosome embryos was similar to the frequency of 21-chromosome oocytes and activated eggs. There was a similar mean number of cells in the embryos with 20 and 21 chromosomes. The results indicate that nearly all the embryos with 19 chromosomes failed to develop, probably beyond the 2-cell stage, whereas oocytes with 21 chromosomes had a similar development to oocytes with 20 chromosomes up to the morula stage.


2009 ◽  
Vol 21 (1) ◽  
pp. 114
Author(s):  
Y. Du ◽  
Z. Yang ◽  
B. Lv ◽  
L. Lin ◽  
P. M. Kragh ◽  
...  

Delayed activation is commonly used in pig somatic cell nuclear transfer (SCNT) where electrical activation is followed by chemical activation. However, chemical incubation of several hours (up to 4 or 6) is logistically not very convenient even though handmade cloning (HMC) could improve the overall efficiency of pig cloning (Du et al. 2007 Theriogenology 68, 1104–1110). It was reported that a brief exposure of cycloheximide (CX) before electrical activation could significantly increase developmental rate and total blastocyst cell number when simultaneous activation was performed in micromanipulator-based pig cloning (Naruse et al. 2007 Theriogenology 68, 709–716). The purpose of our present work is to investigate whether such activation method is also applicable for pig HMC. Data were analyzed by t-test using SPSS (11.0, SPSS Inc., Chicago, IL, USA). After 42 h in vitro maturation, cumulus cells were removed. In vitro-cultured porcine fetal fibroblasts were used as donor cells. Cytoplast-fibroblast pairing, electrical fusion and activation of fused cytoplast-fibroblast pairs were performed as described previously (Kragh et al. 2005 Theriogenology 64, 1536–1545; Du et al. 2005 Cloning Stem Cells 7, 199–205). Three groups were compared due to different activation protocol. In Group 1 (control), reconstructed embryos were cultured in porcine zygote medium 3 (PZM3) supplemented with 4 mg mL–1 BSA, 5 μg mL–1 cytochalasin B (CB), and 10 μg mL–1 CX for 4 h. In Group 2 (CX priming), fused pairs and the other halves of cytoplasts were incubated in HEPES-buffered TCM-199 medium supplemented with 10% calf serum, 10 μg mL–1 CX for 10 min just before the second fusion or electrical activation. In Group 3 (CB + CX priming), treatment similar to Group 2 was performed except that additional 5 μg mL–1 CB was added for the 10-min incubation. Reconstructed embryos were in vitro cultured in the well of the well (WOW) system for 6 days. Blastocyst rates and total cell numbers of Day 6 blastocysts were evaluated. As illustrated in Table 1, embryos pretreated with both CB and CX gave the best results, with better blastocyst formation (53.8 ± 4.8%; mean ± SEM) and higher cell number (77.2 ± 5.4) compared to the other 2 groups. Our data suggested that CX and CB priming could be used as a solution to the long chemical incubation in porcine SCNT by HMC, making the embryos more receptive to electrical activation. Table 1.In vitro development of HMC reconstructed embryos with different activation protocols


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