In vitro oocyte maturation in a medium containing reduced sodium chloride improves the developmental competence of pig oocytes after parthenogenesis and somatic cell nuclear transfer

2017 ◽  
Vol 29 (8) ◽  
pp. 1625
Author(s):  
Joohyeong Lee ◽  
Hanna Lee ◽  
Yongjin Lee ◽  
Bola Park ◽  
Fazle Elahi ◽  
...  

The present study investigated the effects of IVM in hypotonic medium containing reduced (61.6 mM) NaCl compared with isotonic medium containing 108.0 mM NaCl (designated L and N respectively) on oocyte maturation and embryonic development in pigs. IVM culture was divided into four periods at 11-h intervals. Oocytes cultured in N for 33 h and then in L for 11 h of IVM (N-N-N-L) showed significantly improved (P < 0.05) nuclear maturation of oocytes (75.4–79.0% vs 60.2–85.8%) and blastocyst formation (61.5–66.1% vs 45.2–67.5%) after parthenogenesis (PA) compared with other treatments (L-L-L-L, L-L-L-N, L-L-N-L, N-N-L-L, N-N-L-N, L-L-N-L, L-N-N-L and N-L-N-L). Oocytes matured in L-L-L-L and N-N-N-L had an increased (P < 0.05) perivitelline space (11.0–12.5 vs 5.5 µm) and intraoocyte reduced glutathione (GSH) content (1.39–1.41 vs 1.00 pixels per oocyte) relative to oocytes matured in N-N-N-N. Somatic cell nuclear transfer (SCNT) embryos derived from the N-N-N-L treatment had significantly (P < 0.05) higher blastocyst formation (53.5%) than embryos derived from Medium-199 (37.4%) and N-N-N-N (41.8%) treatments. Overall, the results demonstrate that maturation of pig oocytes in hypotonic medium with reduced NaCl during the last 11 h of IVM increases the developmental competence of oocytes after PA and SCNT by improving the cytoplasmic microenvironment, including an increased GSH content in IVM oocytes.

Zygote ◽  
2021 ◽  
pp. 1-8
Author(s):  
Yongjin Lee ◽  
Hanna Lee ◽  
Joohyeong Lee ◽  
Seung Tae Lee ◽  
Geun-Shik Lee ◽  
...  

Summary This study was conducted to examine whether glucose in maturation medium containing reduced NaCl could improve oocyte maturation and embryonic development in pigs. The base medium was bovine serum albumin-free porcine zygote medium (PZM)-3 containing 10% (v/v) pig follicular fluid (FPZM) or 0.1% (w/v) polyvinyl alcohol (PPZM). Using each medium, the effects of NaCl concentrations (108 and 61.6 mM) and 5.56 mM glucose supplementation (designated as PZM108N, PZM108G, PZM61N, and PZM61G, respectively) were examined using a 2 × 2 factorial arrangement. When oocytes were matured in FPZM, glucose supplementation improved nuclear maturation compared with no supplementation, regardless of the NaCl concentrations. FPZM61G showed a higher blastocyst formation compared with FPZM108N and FPZM108G after parthenogenesis (PA). Blastocyst formations of somatic cell nuclear transfer (SCNT) embryos derived from FPZM61N and FPZM61G were higher compared with those of oocytes from FPZM108N. When oocytes were matured in PPZM, glucose added to PPZM108 and PPZM61 increased nuclear maturation compared with no supplementation. However, glucose added to PPZM108 did not alter embryonic development after PA. Additionally, oocytes matured in PPZM61G showed a higher blastocyst formation compared with those from PPZM61N. In SCNT, blastocyst formation was not influenced by glucose supplementation of PPZM108, but was increased by maturation in glucose-supplemented PPZM61. In embryonic development of in vitro fertilization (IVF), oocytes matured in medium with reduced NaCl and glucose showed significantly higher blastocyst formation compared with those matured in PPZM108G. Our results demonstrated that glucose in maturation medium containing 61.6 mM NaCl increased oocyte maturation and embryonic development after PA, SCNT, and IVF.


2018 ◽  
Vol 30 (10) ◽  
pp. 1342 ◽  
Author(s):  
Zhao-Bo Luo ◽  
Long Jin ◽  
Qing Guo ◽  
Jun-Xia Wang ◽  
Xiao-Xu Xing ◽  
...  

Accumulating evidence suggests that aberrant epigenetic reprogramming and low pluripotency of donor nuclei lead to abnormal development of cloned embryos and underlie the inefficiency of mammalian somatic cell nuclear transfer (SCNT). The present study demonstrates that treatment with the small molecule RepSox alone upregulates the expression of pluripotency-related genes in porcine SCNT embryos. Treatment with the histone deacetylase inhibitor LBH589 significantly increased the blastocyst formation rate, whereas treatment with RepSox did not. Cotreatment with 12.5 μM RepSox and 50 nM LBH589 (RepSox + LBH589) for 24 h significantly increased the blastocyst formation rate compared with that of untreated embryos (26.9% vs 8.5% respectively; P < 0.05). Furthermore, the expression of pluripotency-related genes octamer-binding transcription factor 4 (NANOG) and SRY (sex determining region Y)-box 2 (SOX2) were found to significantly increased in the RepSox + LBH589 compared with control group at both the 4-cell and blastocyst stages. In particular, the expression of NANOG was 135-fold higher at the blastocyst stage in the RepSox + LBH589 group. Moreover, RepSox + LBH589 improved epigenetic reprogramming. In summary, RepSox + LBH589 increases the expression of developmentally important genes, optimises epigenetic reprogramming and improves the in vitro development of porcine SCNT embryos.


Zygote ◽  
2017 ◽  
Vol 25 (4) ◽  
pp. 453-461 ◽  
Author(s):  
Xiao-Chen Li ◽  
Qing Guo ◽  
Hai-Ying Zhu ◽  
Long Jin ◽  
Yu-Chen Zhang ◽  
...  

SummaryWe examined the in vitro developmental competence of parthenogenetic activation (PA) oocytes activated by an electric pulse (EP) and treated with various concentrations of AZD5438 for 4 h. Treatment with 10 µM AZD5438 for 4 h significantly improved the blastocyst formation rate of PA oocytes in comparison with 0, 20, or 50 µM AZD5438 treatment (46.4% vs. 34.5%, 32.3%, and 24.0%, respectively; P < 0.05). The blastocyst formation rate was higher in the group treated with AZD5438 for 4 h than in the groups treated with AZD5438 for 2 or 6 h (42.8% vs. 38.6% and 37.2%, respectively; P > 0.05). Furthermore, 66.67% of blastocysts derived from these AZD5438-treated PA oocytes had a diploid karyotype. The blastocyst formation rate of PA and somatic cell nuclear transfer (SCNT) embryos was similar between oocytes activated by an EP and treated with 2 mM 6-dimethylaminopurine for 4 h and those activated by an EP and treated with 10 µM AZD5438 for 4 h (11.11% vs. 13.40%, P > 0.05). In addition, the level of maturation-promoting factor (MPF) was significantly decreased in oocytes activated by an EP and treated with 10 µM AZD5438 for 4 h. Finally, the mRNA expression levels of apoptosis-related genes (Bax and Bcl-2) and pluripotency-related genes (Oct4, Nanog, and Sox2) were checked by RT-PCR; however, there were no differences between the AZD5438-treated and non-treated control groups. Our results demonstrate that porcine oocyte activation via an EP in combination with AZD5438 treatment can lead to a high blastocyst formation rate in PA and SCNT experiments.


2011 ◽  
Vol 23 (1) ◽  
pp. 136 ◽  
Author(s):  
K. Song ◽  
J. Lee ◽  
J. Park ◽  
W. Lee ◽  
Y. Chun ◽  
...  

In Korea, it takes time to transport the ovaries of mares to the laboratory because horses are slaughtered only on Jeju island. Also, initiation of in vitro maturation (IVM) may be a little more delayed because of the oocyte collection by scraping of the follicular wall. It was reported that holding procedure of equine oocytes before IVM did not affect the developmental competence after intracytoplasmic sperm injection (Choi et al. 2006 Theriogenology 66, 955–963). The aims of present study were 1) to investigate the meiotic competence of equine oocytes held before IVM according to the type of oocytes, and 2) to examine the in vitro development after somatic cell nuclear transfer (SCNT). Cumulus–oocyte complexes (COCs) were recovered by scraping and washing of the follicular wall with Dulbecco’s modified Eagle medium (D-MEM) supplemented with 0.05% PVA, and classified as compact (Cp) or expended (Ex) depending on the expansion of cumulus or granulosa cells. 2 types of IVM procedures were compared: 1) COCs were matured immediately in IVM medium (TCM-199 supplemented with 5 mU mL–1 FSH, 50 ng mL–1 EGF, and 10% FBS) at 38.5°C under 5% CO2 in air for 24 to 27 h, and then held in holding medium (40% TCM-199 with Earle’s salts, 40% TCM-199 with Hanks’ salts, and 20% FBS) at room temperature for 6 to 7 h (control); or 2) COCs were initially held in holding medium for 6 to 7 h, and then matured in IVM medium for 24 to 27 h (holding). For SCNT, matured oocytes (pooled) were enucleated and electrically fused with equine skin fibroblasts (2.25 kV cm–1, 20 μs, 2 pulses). Fused couplets were activated with 5 μM ionomycin for 4 min followed by 5 h culture in 2 mM 6-DMAP, and cultured in D-MEM supplemented with 10% FBS and 50 ng mL–1 EGF at 38.5°C under 5% CO2, 5% O2, and 90% N2 for 7 to 9 days. Cleavage and blastocyst formation were evaluated on Days 2 and 8, respectively. All analyses were performed using SAS (version 9.1; SAS Institute Inc., Cary, NC, USA). 4 replicates were conducted from May to June 2010. In Ex oocytes, the maturation rate of the holding group (71.4%; 10/16) was not different from that of the control (65.6%; 44/73), and the rate of degenerated oocytes (4.8%; 1/16) in the holding group was not different from that in the control (5.6%; 5/73). However, in Cp oocytes, the degeneration rate of the holding group (65.0%; 31/49) was higher (P < 0.001) than that of the control (28.4%; 23/83), and the maturation rate of the holding group (20.6%; 12/49) was slightly lower (P = 0.07) than that of the control (46.0%; 38/83). After SCNT, the cleavage rate of the holding group (66.7%; 8/9) was not different from that of the control (60.8%; 14/25), and the rates of blastocyst formation of the control and the holding group were 8.1% (2/25) and 16.7% (2/9), respectively. Although the holding procedure may influence to the degeneration of Cp oocytes, it is considered that the developmental competence of equine oocytes held before IVM is not affected after SCNT.


2011 ◽  
Vol 23 (1) ◽  
pp. 139
Author(s):  
J. You ◽  
N. Kim ◽  
S. Kang ◽  
E. Lee

The size of perivitelline space (PVS) is closely related with the frequency of polyspermic fertilization in pig oocytes. It has been reported that enlargement of PVS is attributed to accumulation of glycoproteins synthesised and secreted from cumulus cells and that culture of immature oocytes in low-salt medium enlarges PVS in pigs. This study examined the developmental competence of pig oocytes after parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) in relation to the size of the PVS of oocytes matured in vitro (IVM). Cumulus–oocyte complexes were matured in medium 199 (Experiment 1) or porcine zygote medium (PZM)-3 (Experiment 2) supplemented with pig follicular fluid, cysteine, pyruvate, EGF, insulin, and hormones for the first 22 h and then cultured in hormone-free medium for an additional 22 h. IVM oocytes were activated electrically for PA or used as recipient cytoplasts for SCNT. PA and SCNT embryos were cultured for 7 days in PZM-3 medium supplemented with bovine serum albumin. The intracellular glutathione (GSH) level in IVM oocytes was determined by analysing the fluorescence intensity of oocytes after staining with CellTracker Blue CMF2HC. The expression of CDK1, PCNA, and ERK2 mRNA in IVM oocytes was analysed by RT-PCR. Data were analysed using a general linear model procedure followed by the least significant difference mean separation procedure when the treatments differed at P < 0.05. In Experiment 1, oocytes with a larger PVS had higher (P < 0.05) levels of intracellular GSH (1.0 pixels/oocyte v. 0.6 pixels/oocyte) and blastocyst formation (54% v. 37%) after PA than oocytes with smaller PVS. In Experiment 2, maturation culture of oocytes in PZM-3 with reduced (61.6 mM) NaCl concentration significantly increased (P < 0.05) the size of the PVS (5.2 μM v. 3.3 μM) compared with control oocytes that were matured in PZM-3 containing 108 mM NaCl, although the treatment did not alter the nuclear maturation. Moreover, oocytes with increased PVS expressed more CDK1, PCNA, and ERK2 mRNA and had higher (P < 0.05) intracellular GSH levels (1.6 pixels/oocyte v. 1.2 pixels/oocyte) and increased blastocyst formation after PA (52% v. 41%) and SCNT (32% v. 18%) compared with control oocytes. Our results demonstrate that pig oocytes with a large PVS have greater developmental competence after PA and SCNT, which is attributed to improved cytoplasmic maturation resulting from the enhanced GSH level and transcription factor expression and that enlargement of PVS by the culture in low-NaCl medium also improves developmental competence of pig oocytes. This work was supported by grants (#20070301034040 and #20080401034072) from the BioGreen 21 Program (Rural Development Administration, Republic of Korea).


2018 ◽  
Vol 24 (1) ◽  
pp. 29-37 ◽  
Author(s):  
Shuang Liang ◽  
Zheng-Wen Nie ◽  
Jing Guo ◽  
Ying-Jie Niu ◽  
Kyung-Tae Shin ◽  
...  

AbstractMicroRNA (miR)-29b plays a crucial role during somatic cell reprogramming. The aim of the current study was to explore the effects of miR-29b on the developmental competence of bovine somatic cell nuclear transfer (SCNT) embryos, as well as the underlying mechanisms of action. The expression level of miR-29b was lower in bovine SCNT embryos at the pronuclear, 8-cell, and blastocyst stages compared within vitrofertilized embryos. In addition, miR-29b regulates the expression of DNA methyltransferases (Dnmt3a/3bandDnmt1) in bovine SCNT embryos. We further investigated SCNT embryo developmental competence and found that miR-29b overexpression during bovine SCNT embryonic development does not improve developmental potency and downregulation inhibits developmental potency. Nevertheless, the quality of bovine SCNT embryos at the blastocyst stage improved significantly. The expression of pluripotency factors and cellular proliferation were significantly higher in blastocysts from the miR-29b overexpression group than the control and downregulation groups. In addition, outgrowth potential in blastocysts after miR-29b overexpression was also significantly greater in the miR-29b overexpression group than in the control and downregulation groups. Taken together, these results demonstrated that miR-29b plays an important role in bovine SCNT embryo development.


2005 ◽  
Vol 7 (1) ◽  
pp. 17-26 ◽  
Author(s):  
Yoichiro Hoshino ◽  
Masaki Uchida ◽  
Yoshiki Shimatsu ◽  
Masashi Miyake ◽  
Yasumitsu Nagao ◽  
...  

Author(s):  
Zhenhua Guo ◽  
Lei Lv ◽  
Di Liu ◽  
Zhongqiu Li

Herd boars, male domestic pigs used for stud, are economically important, and somatic cell nuclear transfer (SCNT) is a promising technology to expand herd boar yields. However, live births are dictated by donor cell source, and fetal donors may offer more advantages than adult donors. A meta-analysis was conducted to better understand how donor sources affect SCNT outcomes. Of the 1,431 records viewed, 10 were selected for review. Blastocyst formation rates, successful pregnancies, and live births were assessed to measure efficacy. SCNT blastocyst formation differed between adult and fetal donors among the studies. SCNT pigs had more malformed fetuses as well, which negatively affected the post-birth mortality. Organs of porcine fetuses are limited by deficiencies of maternal nutrient and growth hormones, which compromise post-birth adaptations. SCNT pregnancy success is neither determined by donor source nor by live births. Live births are also tied to donor age. Embryos from fetal donors are more frequently healthy likely due to less differentiation and less reprogramming of reconstructed embryos. Adult donors in contrast have more cell differentiation and as such accumulate more mutations and damage. This may reduce reconstructed embryo viability. Finally, SCNT efficiency may be improved with more in vitro passages, but more work is required to validate this concept.


2015 ◽  
Vol 27 (3) ◽  
pp. 544 ◽  
Author(s):  
H. S. Pedersen ◽  
Y. Liu ◽  
R. Li ◽  
S. Purup ◽  
P. Løvendahl ◽  
...  

Pig oocytes have been used increasingly for in vitro production techniques in recent years. The slaughterhouse-derived oocytes that are often used are mostly of prepubertal origin. The aims of the present study were to compare the developmental competence between pre- and postpubertal pig oocytes, and to develop a simple and practical method for the selection of prepubertal pig oocytes for parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) based on oocyte morphology after IVM and oocyte inside zona pellucida (ZP) diameter (‘small’ ≤110 µm; ‘medium’ >110 µm; ‘large’ ≥120 µm). Meiotic competence and blastocyst rates after PA and SCNT of prepubertal oocytes increased with oocyte size, with the large prepubertal oocytes reaching a level similar to postpubertal oocytes after SCNT. Blastocyst cell number was not related to oocyte inside ZP diameter and oocyte donor to the same extent as blastocyst rate. Very low blastocyst rates were obtained after PA of morphologically bad pre- and postpubertal oocytes. In conclusion, measurement of inside ZP diameter combined with morphological selection is useful to remove incompetent oocytes. Further studies are needed to clarify the relative importance of cytoplasmic volume and stage in oocyte growth phase.


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