Advances in equine cloning by somatic cell nuclear transfer (SCNT) technique in horses: a review

2016 ◽  
Vol 5 (12) ◽  
pp. 5124
Author(s):  
Rajesh Wakchaure ◽  
Subha Ganguly*
Keyword(s):  
In Vitro Culture ◽  
Somatic Cell ◽  
Oocyte Maturation ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Genetic Material ◽  
Culture Conditions ◽  
Preimplantation Embryos ◽  
Oocyte Activation

Cloning a horse means using the genetic material (DNA) from a donor horse to produce a genetically identical foal. This technique involves collecting the DNA from the donor and inserting that DNA into an egg from another mare whose, DNA content has been removed, fusing donor nucleus with enucleated recipient oocytes, which then develops as an embryo, in vitro culture of embryo and lastly transfer cultured embryo into the uterus of a recipient mare. The modification of the in vitro culture conditions which can be suitable for equine oocyte activation, oocyte maturation and embryo development are the fundamental steps for a successful in vitro procedure for somatic cell nuclear transfer (SCNT) in the horse to avoid the embryo losses. In general, few studies are available in the literature on equine in vitro embryo production and it is only recently that reports have been published on completely in vitro production of equine preimplantation embryos by means of in vitro oocyte maturation The present review discusses the latest developments in the field of equine cloning technique with the employment of SCNT. The basic understanding of SCNT for in vitro culture conditions is relevant to the increased efficiency of cloning. The available genotype can be used by SCNT which can enhance the vigour of a particular infertile or low fertile animal to produce normal fertility.

Effects of VEGF on Porcine In Vitro Fertilized and Somatic Cell Nuclear Transfer (SCNT) Preimplantation Embryos.

2010 ◽  
Vol 83 (Suppl_1) ◽  
pp. 417-417
Author(s):  
Dibyendu Biswas ◽  
Yu-Byeol Jeon ◽  
Eui Man Jung ◽  
Eui Bae Jeung ◽  
Sang-Hwan Hyun
Keyword(s):  
Somatic Cell ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Preimplantation Embryos

Glucose in a maturation medium with reduced NaCl improves oocyte maturation and embryonic development after somatic cell nuclear transfer and in vitro fertilization in pigs

Zygote ◽  
2021 ◽  
pp. 1-8
Author(s):  
Yongjin Lee ◽  
Hanna Lee ◽  
Joohyeong Lee ◽  
Seung Tae Lee ◽  
Geun-Shik Lee ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Somatic Cell ◽  
Oocyte Maturation ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Blastocyst Formation ◽  
Nuclear Maturation ◽  
Maturation Medium ◽  
Glucose Supplementation

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.

TRIM28 down-regulation on methylation imprints in bovine preimplantation embryos

Zygote ◽  
2018 ◽  
Vol 26 (6) ◽  
pp. 449-456 ◽  
Author(s):  
Xin Ma ◽  
Sheng Zhang ◽  
Meiling Zhang ◽  
Yiran Zhu ◽  
Panpan Ma ◽  
...  
Keyword(s):  
Oocyte Maturation ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Preimplantation Embryos ◽  
Differentially Methylated Region ◽  
Fibroblast Cells ◽  
Mrna Sequence ◽  
Cell Stage ◽  
H19 Gene

SummaryTRIM28/KAP1/TIF1β was identified as a universal transcriptional co-repressor and is critical for regulating post-fertilization methylation reprogramming in preimplantation embryos. In this study, three siRNAs (si647, si742, and si1153) were designed to target the TRIM28 mRNA sequence. After transfection of the mixture of the three siRNA (siMix) into bovine fibroblast cells, the most effective one for TRIM28 knockdown was selected. By injecting RNAi directed against TRIM28 mRNA, we found that TRIM28 knockdown in oocytes had the most effect on the H19 gene, in which differentially methylated region (DMR) methylation was almost completely absent at the 2-cell stage (1.4%), while control embryos showed 74% methylation. In addition, global H3K9me3 levels at the 2-cell stage were significantly higher in the in vitro fertilization (IVF) group than in the TRIM28 knockdown group (P<0.05). We further show that TRIM28 is highly expressed during oocyte maturation and reaches peak levels at the 2-cell stage. In contrast, at this stage, TRIM28 expression in somatic cell nuclear transfer (SCNT) embryos decreased significantly (P<0.05), suggesting that Trim28 transcripts are lost during SCNT. TRIM28 is required for the maintenance of methylation imprints in bovine preimplantation embryos, and the loss of TRIM28 during SCNT may contribute to the unfaithful maintenance of imprints in cloned embryos.

27 SOMATIC CELL NUCLEAR TRANSFER CLONING AND EMBRYO AGGREGATION IN PIGS

2014 ◽  
Vol 26 (1) ◽  
pp. 128
Author(s):  
C. P. Buemo ◽  
A. Gambini ◽  
I. Hiriart ◽  
D. Salamone
Keyword(s):  
In Vitro Culture ◽  
Somatic Cell ◽  
Embryo Development ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Electric Pulse ◽  
Blastocyst Stage ◽  
Control Group

Somatic cell nuclear transfer (SCNT) derived blastocysts have lower cell number than IVF-derived blastocysts and their in vivo counterparts. The aim of this study was to improve the blastocyst rates and quality of SCNT blastocysts by the aggregation of genetically identical free zona pellucida (ZP) porcine clones. Cumulus–oocyte complexes were recovered from slaughterhouse ovaries by follicular aspiration. Maturation was performed in TCM for 42 to 48 h at 39°C and 5% CO2. After denudation by treatment with hyaluronidase, mature oocytes were stripped of the ZP using a protease and then enucleated by micromanipulation; staining was performed with Hoechst 33342 to observe metaphase II. Ooplasms were placed in phytohemagglutinin to permit different membranes to adhere between each other; the ooplasm membrane was adhered to a porcine fetal fibroblast from an in vitro culture. Adhered membranes of the donor cell nucleus and enucleated oocyte cytoplasm were electrofused through the use of an electric pulse (80 V for 30 μs). All reconstituted embryos (RE) were electrically activated using an electroporator in activation medium (0.3 M mannitol, 1.0 mM CaCl2, 0.1 mM MgCl2, and 0.01% PVA) by a DC pulse of 1.2 kV cm–1 for 80 μs. Then, the oocytes were incubated in 2 mM 6-DMAP for 3 h. In vitro culture of free ZP embryos was achieved in a system of well of wells in 100 μL of medium, placing 3 activated oocytes per microwell (aggregation embryo), whereas the control group was cultivated with equal drops without microwells. Embryos were cultivated at 39°C in 5% O2, 5% CO2 for 7 days in SOF medium with a supplement of 10% fetal bovine serum on the fifth day. The RE were placed in microwells. Two experimental groups were used, control group (not added 1X) and 3 RE per microwell (3X). At Day 7, resulting blastocysts were classified according to their morphology and diameter to determine their quality and evaluate if the embryo aggregation improves it. Results demonstrated that aggregation improves in vitro embryo development rates until blastocyst stage and indicated that blastocysts rates calculated over total number of oocytes do not differ between groups (Table 1). Embryo aggregation improves cleavage per oocyte and cleavage per microwell rates, presenting statistical significant differences and increasing the probabilities of higher embryo development generation until the blastocyst stage with better quality and higher diameter. Table 1.Somatic cell nuclear transfer cloning and embryo aggregation

Parthenogenetic activation and somatic cell nuclear transfer of porcine oocytes activated by an electric pulse and AZD5438 treatment

Zygote ◽  
2017 ◽  
Vol 25 (4) ◽  
pp. 453-461 ◽  
Author(s):  
Xiao-Chen Li ◽  
Qing Guo ◽  
Hai-Ying Zhu ◽  
Long Jin ◽  
Yu-Chen Zhang ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Electric Pulse ◽  
Formation Rate ◽  
Developmental Competence ◽  
Oocyte Activation ◽  
Blastocyst Formation ◽  
Parthenogenetic Activation

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.

scholarly journals Phosphorylated histone H2A.x in porcine embryos produced by IVF and somatic cell nuclear transfer

Reproduction ◽  
2013 ◽  
Vol 146 (4) ◽  
pp. 325-333 ◽  
Author(s):  
Rodrigo C Bohrer ◽  
Limei Che ◽  
Paulo B D Gonçalves ◽  
Raj Duggavathi ◽  
Vilceu Bordignon
Keyword(s):  
Somatic Cell ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Chloride Ion ◽  
Dna Integrity ◽  
Strontium Chloride ◽  
Oocyte Activation ◽  
Dna Double Strand Breaks ◽  
Cell Stage

Phosphorylated histone H2A.x (H2AX139ph) is a key factor for the repair of DNA double-strand breaks (DSBs) and the presence of H2AX139ph foci indicates the sites of DSBs. In this study, we characterized the presence of H2AX139ph during in vitro development of porcine embryos produced by IVF and somatic cell nuclear transfer (SCNT). Pronuclear stage embryos produced by IVF had, on average, 9.2 H2AX139ph foci per pronucleus. The number of H2AX139ph foci was higher in the 2-cell-stage embryos than in the 4-cell-stage embryos fixed at 48 h post-fertilization. The percentage of H2AX139ph-positive nuclei was higher in SCNT embryos that were activated with ionomycin (ION) alone than in those activated with ION and strontium chloride (ION+Sr2+). A negative correlation was found between the percentage of H2AX139ph-positive cells and the total number of cells per embryo in day 7 blastocysts produced by IVF or SCNT. Based on the detection of H2AX139ph foci, the findings of this study indicate that DSBs occur in a high proportion of porcine embryos produced by either IVF or SCNT; fast-cleaving embryos have fewer DSBs than slow-cleaving embryos; the oocyte activation protocol can affect DNA integrity in SCNT embryos; and better-quality blastocysts have fewer DSBs. We propose that the presence of H2AX139ph foci can be a useful marker of embryo quality.

38 DNA METHYLATION IN PORCINE PREIMPLANTATION EMBRYOS DEVELOPED IN VIVO AND PRODUCED BY IN VITRO FERTILIZATION, PARTHENOGENETIC ACTIVATION, AND SOMATIC CELL NUCLEAR TRANSFER

2011 ◽  
Vol 23 (1) ◽  
pp. 125
Author(s):  
R. S. Deshmukh ◽  
O. Oestrup ◽  
E. Oestrup ◽  
M. Vejlsted ◽  
H. Niemann ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Somatic Cell ◽  
Somatic Cell Nuclear Transfer ◽  
Nuclear Transfer ◽  
Cell Mass ◽  
Epifluorescence Microscopy ◽  
Preimplantation Embryos ◽  
Parthenogenetic Activation

DNA de- and re-methylation are crucial for reprogramming of the differentiated parental/somatic genome in the ooplasm. The presented research was aimed at analysis of the DNA methylation dynamics in porcine preimplantation embryos developed in vivo (IV) and produced in vitro by IVF, somatic cell nuclear transfer (SCNT), and parthenogenetic activation (PA). Embryos of early and late 1-cell, 2-, 4-, and 8-cell, and early and late blastocysts stages obtained by the mentioned methods were fixed in 4% paraformaldehyde and subjected to immunocytochemistry using anti-5MetC (Mouse monoclonal, Abcam, Cambridge, MA, USA) antibody. DNA was labelled using Hoechst 33258 (Sigma, Copenhagen, Denmark). Epifluorescence microscopy (Leica Microsystems, Wetzlar, Germany) images were subjected to NIH imageJ software to measure the DNA methylation/DNA content signal by manually outlining the nuclei (n = 2003) of the embryos. The data were analysed using PROC-GLM statistical procedure in SAS 9.1 (SAS Institute Inc., Cary, NC, USA), least square means were compared and P-values were used to decide the significant differences within and between different groups of embryos. The 1-cell stages lacked active demethylation of paternal genome in IV and IVF embryos. Embryos produced under in vitro conditions presented higher levels of DNA methylation than IV. A lineage specific DNA methylation (hypermethylation of inner cell mass and hypomethylation of trophectoderm) observed in porcine IV late blastocysts was absent in PA and SCNT blastocysts despite the occurrence of de novo methylation in early blastocysts. SCNT early (50%) and late (14%) blastocysts presented DNA methylation pattern similar to IV early and late blastocysts, respectively. Concluding, DNA methylation patterns are strongly impaired under in vitro conditions in porcine preimplantation embryos.

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