1
|
Lee K, Wang C, Spate L, Murphy CN, Prather RS, Machaty Z. Gynogenetic Activation of Porcine Oocytes. Cell Reprogram 2014; 16:121-9. [DOI: 10.1089/cell.2013.0074] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Kiho Lee
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65201
- These authors contributed equally to this work
| | - Chunmin Wang
- Department of Animal Sciences, Purdue University, West Lafayette, IN, 47907
- These authors contributed equally to this work
| | - Lee Spate
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65201
| | - Clifton N. Murphy
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65201
| | - Randall S. Prather
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65201
| | - Zoltan Machaty
- Department of Animal Sciences, Purdue University, West Lafayette, IN, 47907
| |
Collapse
|
2
|
Samiec M, Skrzyszowska M. Biological transcomplementary activation as a novel and effective strategy applied to the generation of porcine somatic cell cloned embryos. Reprod Biol 2014; 14:128-39. [PMID: 24856472 DOI: 10.1016/j.repbio.2013.12.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2013] [Accepted: 12/23/2013] [Indexed: 11/26/2022]
Abstract
A novel method termed the biological transcomplementary activation (B-TCA) has been recently utilized for the stimulation of porcine oocytes reconstituted by somatic cell nuclear transfer (SCNT). The use of cytosolic components originating from fertilized (FE) rabbit zygotes as the stimuli for the B-TCA of SCNT-derived pig oocytes appeared to be a highly efficient strategy applied to promote the in vitro development of cloned embryos, leading to a significant improvement in the blastocyst yield (43.6%) compared to the yields achieved using the standard protocol of simultaneous fusion and electrical activation (SF-EA; [31.3%]) or the protocol of delayed electrical activation (D-EA) independent of extracellular Ca(2+) ions (0%). The FE rabbit zygote cytoplast-mediated B-TCA resulted in the increased blastocyst formation rate of porcine cloned embryos as compared to the B-TCA triggered by either cytoplasts isolated from pig parthenogenotes (PAs; [27.8%]) or rabbit PA-descended cytoplasts (0%). A considerably lower percentage of blastocysts containing apoptotic and/or necrotic (annexin V-eGFP-positive) cells were obtained from the SCNT-derived oocytes stimulated by the FE rabbit zygote cytoplast-based B-TCA (22.2%) compared to those stimulated using the SF-EA protocol (35.1%). In contrast to the B-TCA induced by FE rabbit zygote cytoplasts, apoptosis/necrosis incidence decreased totally among the cloned pig blastocysts that developed from reconstituted oocytes undergoing the porcine PA cytoplast-evoked B-TCA. In conclusion, the FE rabbit zygote cytoplast-mediated B-TCA turned out to be a relatively effective strategy for the in vitro production of porcine blastocyst clones of higher quality compared to those created using the standard SF-EA approach.
Collapse
Affiliation(s)
- Marcin Samiec
- Department of Biotechnology of Animal Reproduction, National Research Institute of Animal Production, Balice n. Cracow, Poland.
| | - Maria Skrzyszowska
- Department of Biotechnology of Animal Reproduction, National Research Institute of Animal Production, Balice n. Cracow, Poland
| |
Collapse
|
3
|
Pribenszky C, Lin L, Du Y, Losonczi E, Dinnyes A, Vajta G. Controlled Stress Improves Oocyte Performance - Cell Preconditioning in Assisted Reproduction. Reprod Domest Anim 2012; 47 Suppl 4:197-206. [DOI: 10.1111/j.1439-0531.2012.02076.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
4
|
WHITWORTH KRISTINM, PRATHER RANDALLS. Somatic cell nuclear transfer efficiency: how can it be improved through nuclear remodeling and reprogramming? Mol Reprod Dev 2010; 77:1001-15. [PMID: 20931660 PMCID: PMC4718708 DOI: 10.1002/mrd.21242] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2010] [Accepted: 08/23/2010] [Indexed: 01/01/2023]
Abstract
Fertile offspring from somatic cell nuclear transfer (SCNT) is the goal of most cloning laboratories. For this process to be successful, a number of events must occur correctly. First the donor nucleus must be in a state that is amenable to remodeling and subsequent genomic reprogramming. The nucleus must be introduced into an oocyte cytoplasm that is capable of facilitating the nuclear remodeling. The oocyte must then be adequately stimulated to initiate development. Finally the resulting embryo must be cultured in an environment that is compatible with the development of that particular embryo. Much has been learned about the incredible changes that occur to a nucleus after it is placed in the cytoplasm of an oocyte. While we think that we are gaining an understanding of the reorganization that occurs to proteins in the donor nucleus, the process of cloning is still very inefficient. Below we will introduce the procedures for SCNT, discuss nuclear remodeling and reprogramming, and review techniques that may improve reprogramming. Finally we will briefly touch on other aspects of SCNT that may improve the development of cloned embryos.
Collapse
Affiliation(s)
| | - RANDALL S. PRATHER
- Division of Animal Sciences, University of Missouri, Columbia, Missouri
- National Swine Resource and Research Center, University of Missouri, Columbia, Missouri
| |
Collapse
|
5
|
You J, Song K, Lee E. Prolonged interval between fusion and activation impairs embryonic development by inducing chromosome scattering and nuclear aneuploidy in pig somatic cell nuclear transfer. Reprod Fertil Dev 2010; 22:977-86. [PMID: 20591332 DOI: 10.1071/rd09309] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 01/27/2010] [Indexed: 11/23/2022] Open
Abstract
The aim of the present study was to examine the effect of various intervals between electrofusion and activation (FA interval) on the nuclear remodelling and development of somatic cell nuclear transfer (SCNT) embryos in pigs. Reconstructed oocytes were activated at 0 (simultaneous fusion and activation; SFA), 1, 2 and 3 h (delayed activation) after electrofusion; these groups were designated as DA1, DA2 and DA3, respectively. When oocyte nuclear status was examined at 0.5, 1, 2 and 3 h after electrofusion, the incidence of chromosome scattering was increased (P < 0.01) as the FA interval was extended (0.0%, 12.0%, 77.3% and 78.0%, respectively). Extending the FA interval led to an increase (P < 0.01) in the percentage of oocytes containing multiple (>or=3) pseudopronuclei (PPN) (0.0% of SFA; 5.3% of DA1; 21.7% of DA2; and 33.5% of DA3). The development of SCNT embryos to the blastocyst stage was decreased (P < 0.05) in DA2 (5.7%) and DA3 (5.0%) compared with SFA (18.1%) and DA1 (19.5%). Our results demonstrate that extending the FA interval impairs the development of SCNT pig embryos by inducing chromosome scattering and the formation of multiple PPN, which may result in increased nuclear aneuploidy.
Collapse
Affiliation(s)
- Jinyoung You
- College of Veterinary Medicine, Kangwon National University, Chuncheon, Korea
| | | | | |
Collapse
|
6
|
Lin L, Pribenszky C, Molnár M, Kragh PM, Du Y, Zhang X, Yang H, Bolund L, Callesen H, Macháty Z, Vajta G. High Hydrostatic Pressure Treatment of Porcine Oocytes Induces Parthenogenetic Activation. Cell Reprogram 2010; 12:475-80. [DOI: 10.1089/cell.2009.0115] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- Lin Lin
- Department of Genetics and Biotechnology, Aarhus University, Tjele, Denmark
- Institute of Human Genetics, Aarhus University, Aarhus, Denmark
- BGI/HuaDa Shenzhen, Shenzhen, People's Republic of China
| | - Csaba Pribenszky
- Clinic for Large Animals, Faculty of Veterinary Science, Szent István University, Üllő, Dóra major, Hungary
| | - Miklós Molnár
- Clinic for Large Animals, Faculty of Veterinary Science, Szent István University, Üllő, Dóra major, Hungary
| | - Peter M Kragh
- Department of Genetics and Biotechnology, Aarhus University, Tjele, Denmark
| | - Yutao Du
- BGI/HuaDa Shenzhen, Shenzhen, People's Republic of China
| | - Xiuqing Zhang
- BGI/HuaDa Shenzhen, Shenzhen, People's Republic of China
| | - Huanming Yang
- BGI/HuaDa Shenzhen, Shenzhen, People's Republic of China
| | - Lars Bolund
- Institute of Human Genetics, Aarhus University, Aarhus, Denmark
- BGI/HuaDa Shenzhen, Shenzhen, People's Republic of China
| | - Henrik Callesen
- Department of Genetics and Biotechnology, Aarhus University, Tjele, Denmark
| | - Zoltán Macháty
- Department of Animal Sciences, Purdue University, West Lafayette, Indiana
| | - Gábor Vajta
- Department of Genetics and Biotechnology, Aarhus University, Tjele, Denmark
| |
Collapse
|
7
|
Miranda MDS, Bressan FF, Zecchin KG, Vercesi AE, Mesquita LG, Merighe GKF, King WA, Ohashi OM, Pimentel JRV, Perecin F, Meirelles FV. Serum-Starved Apoptotic Fibroblasts Reduce Blastocyst Production but Enable Development to Term after SCNT in Cattle. CLONING AND STEM CELLS 2009; 11:565-73. [DOI: 10.1089/clo.2009.0028] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Affiliation(s)
- Moysés dos Santos Miranda
- Departamento de Ciências Básicas, FZEA-USP, Pirassununga-SP, Brazil
- Departamento de Biologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém-PA, Brazil
| | | | | | - Anibal Eugênio Vercesi
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, UNICAMP, Campinas-SP, Brazil
| | | | | | - William Allan King
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, ON, Canada
| | - Otávio Mitio Ohashi
- Departamento de Biologia, Instituto de Ciências Biológicas, Universidade Federal do Pará, Belém-PA, Brazil
| | - José Rodrigo Valim Pimentel
- Departmento de Reprodução Animal, Faculdade de Medicina Veterinária, Universidade de São Paulo, Sao Paulo-SP, Brazil
| | - Felipe Perecin
- Departamento de Ciências Básicas, FZEA-USP, Pirassununga-SP, Brazil
| | | |
Collapse
|
8
|
Whitworth KM, Li R, Spate LD, Wax DM, Rieke A, Whyte JJ, Manandhar G, Sutovsky M, Green JA, Sutovsky P, Prather RS. Method of oocyte activation affects cloning efficiency in pigs. Mol Reprod Dev 2009; 76:490-500. [PMID: 19090011 DOI: 10.1002/mrd.20987] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The following experiments compared the efficiency of three fusion/activation protocols following somatic cell nuclear transfer (SCNT) with porcine somatic cells transfected with enhanced green fluorescent protein driven by the chicken beta-actin/rabbit beta-globin hybrid promoter (pCAGG-EGFP). The three protocols included electrical fusion/activation (NT1), electrical fusion/activation followed by treatment with a reversible proteasomal inhibitor MG132 (NT2) and electrical fusion in low Ca(2+) followed by chemical activation with thimerosal/dithiothreitol (NT3). Data were collected at Days 6, 12, 14, 30, and 114 of gestation. Fusion rates, blastocyst-stage mean cell numbers, recovery rates, and pregnancy rates were calculated and compared between protocols. Fusion rates were significantly higher for NT1 and NT2 compared to NT3 (P < 0.05). There was no significant difference in mean nuclear number. Pregnancy rate for NT2 was 100% (n = 19) at all stages collected and was significantly higher than NT1 (71.4%, n = 28; P < 0.05), but was not significantly higher than NT3 (82.6%, n = 23; P < 0.15). Recovery rates were calculated based on the number of embryos, conceptuses, fetuses, or piglets present at the time of collection, divided by the number of embryos transferred to the recipient gilts. Recovery rates between the three groups were not significantly different at any of the stages collected (P > 0.05). All fusion/activation treatments produced live, pCAGG-EGFP positive piglets from SCNT. Treatment with MG132 after fusion/activation of reconstructed porcine embryos was the most effective method when comparing the overall pregnancy rates. The beneficial effect of NT2 protocol may be due to the stimulation of proteasomes that infiltrate donor cell nucleus shortly after nuclear transfer.
Collapse
Affiliation(s)
- Kristin M Whitworth
- Division of Animal Sciences, University of Missouri, Columbia, Missouri 65211, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
9
|
Song K, Hyun SH, Shin T, Lee E. Post-activation treatment with demecolcine improves development of somatic cell nuclear transfer embryos in pigs by modifying the remodeling of donor nuclei. Mol Reprod Dev 2008; 76:611-9. [DOI: 10.1002/mrd.20989] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
10
|
García-Roselló E, García-Mengual E, Coy P, Alfonso J, Silvestre MA. Intracytoplasmic sperm injection in livestock species: an update. Reprod Domest Anim 2008; 44:143-51. [PMID: 18954388 DOI: 10.1111/j.1439-0531.2007.01018.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Intracytoplasmic sperm injection (ICSI) is a powerful technique in the field of assisted reproduction (ART) and provides exciting opportunities for studying the basic mechanisms of fertilization and early embryo development. Nevertheless, its application in agriculture and conservation biology has been greatly hampered by the low success rate reported for this method in respect of economically important species. Specifically, the rates of blastocyst formation and live newborn are greatly reduced when zygotes are generated by ICSI. Except for humans, ICSI remains a low efficiency technology in comparison with alternatives such as in vitro fertilization (IVF) and its application is less widespread. In this paper, we discuss the present status, applications and factors affecting ICSI in pigs and other species.
Collapse
Affiliation(s)
- E García-Roselló
- Dpto. Medicina y Cirugía Animal, Facultad de Ciencias Experimentales y de la Salud, Universidad CEU-Cardenal Herrera, Edificio Seminario, Moncada, Spain.
| | | | | | | | | |
Collapse
|
11
|
Lee SR, Kim JW, Kim BS, Kim MO, Kim SH, Yoo DH, Shin MJ, Lee S, Park YS, Park YB, Ha JH, Ryoo ZY. The parthenogenetic activation of canine oocytes with Ca-EDTA by various culture periods and concentrations. Theriogenology 2007; 67:698-703. [PMID: 17125828 DOI: 10.1016/j.theriogenology.2006.10.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2006] [Accepted: 10/12/2006] [Indexed: 10/23/2022]
Abstract
In the present study, canine oocytes were exposed to various concentrations of and durations of exposure to EDTA saturated with Ca(2+) (Ca-EDTA), a cell membrane-impermeable metal ion chelator, to determine if parthenogenetic activation could be induced. When oocytes were cultured for 48 or 72 h in parthenogenetic activation medium (PAM) without Ca-EDTA (control) or PAM supplemented with 1 or 5mM Ca-EDTA, the highest rate of pronuclear formation (PN) was obtained in oocytes cultured in 1mM Ca-EDTA for 48 h (8.0%; P<0.05). There was no pronuclear formation in the control group (PAM without Ca-EDTA). Oocytes treated with 5mM Ca-EDTA for 48 h or 1mM Ca-EDTA for 72 h formed a parthenogenetic pronucleus (3.1 and 4.5, respectively). However, there was no pronuclear formation in oocytes treated with 5mM Ca-EDTA for 72 h. In summary, exposure to Ca-EDTA can induce pronuclear formation in canine oocytes.
Collapse
Affiliation(s)
- Sang Ryeul Lee
- School of Life Science and Biotechnology, Kyungpook National University, 1370 Sankyuk-dong, Buk-ku, Daegu 702-701, Republic of Korea
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
12
|
Giraldo AM, Lynn JW, Purpera MN, Godke RA, Bondioli KR. DNA methylation and histone acetylation patterns in cultured bovine fibroblasts for nuclear transfer. Mol Reprod Dev 2007; 74:1514-24. [PMID: 17440941 DOI: 10.1002/mrd.20740] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Evidence indicates that failure of nuclear transfer (NT) embryos to develop normally can be attributed, at least partially, to the use of a differentiated cell nucleus as the donor karyoplast. It has been hypothesized that blastocyst production and development to term of cloned embryos may differ between population doublings (PDs) of the same cell line as a consequence of changes in DNA methylation and histone acetylation patterns during in vitro culture. The objective of this study was to determine gene expression patterns of the chromatin remodeling proteins DNA methyltransferase-1 (Dnmt1), methyl CpG binding protein-2 (MeCP2), and histone deacetyltransferse-1 (HDAC1), in addition, to measuring levels of DNA methylation and histone acetylation of bovine fibroblast cells at different PDs. Bovine fibroblast cell lines were established from four 50-day fetuses. Relative levels of Dnmt1, MeCP2, HDAC1, methylated DNA, and acetylated histone were analyzed at PDs 2, 7, 15, 30, 45, and 70. RNA levels of Dnmt1, HDAC1, and MeCP2 were examined using Q-PCR. Global levels of methylated DNA and acetylated histone were determined by incubation of fixed cells with an anti-5-methylcytidine and anti-acetyl-histone H3 antibody, respectively. Cells were labeled with a second antibody, counter-stained with propidium iodide and analyzed by flow cytometry. These data demonstrate that chromatin remodeling protein mRNAs involved in epigenetic modifications are altered during in vitro culture. Methylated DNA and acetylated histone patterns of in vitro cells change with time in culture. Subsequent use of these cells for NT will provide insight as to how these epigenetic modifications affect reprogramming.
Collapse
Affiliation(s)
- Angelica M Giraldo
- Department of Animal Sciences, Louisiana State University Agricultural Center, Baton Rouge, Louisiana 70803, USA
| | | | | | | | | |
Collapse
|
13
|
Leal C, Méo S, Garcia J. Activation of bovine oocytes by strontium combined or not with an electric pulse. ARQ BRAS MED VET ZOO 2003. [DOI: 10.1590/s0102-09352003000300020] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
|
14
|
Booth PJ, Tan SJ, Reipurth R, Holm P, Callesen H. Simplification of bovine somatic cell nuclear transfer by application of a zona-free manipulation technique. CLONING AND STEM CELLS 2002; 3:139-50. [PMID: 11945223 DOI: 10.1089/153623001753205098] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Contemporary nuclear transfer techniques often require the involvement of skilled personnel and extended periods of micromanipulation. Here, we present details of the development of a nuclear transfer technique for somatic cells that is both simpler and faster than traditional methods. The technique comprises the bisection of zona-free oocytes and the reconstruction of embryos comprising two half cytoplasts and a somatic cell by adherence using phytohaemagglutinin-P (PHA) followed by an electropulse and subsequent culture in microwells (termed WOWs--well of the well). The development of the system was based on results using parthenogenetic and in vitro fertilized zygotes in order to (a) select the optimal primary activation agent that induced the lowest lysis rate but highest parthenogenetic blastocyst yield, (b) evaluate the quantity and quality of zona-free blastocysts produced in WOWs, and (c) establish any potential embryotoxic effects of PHA-P. The initial data indicated that, of calcium ionophore A23187, ionomycin, and electropulse treatments as primary activation agents, the two former were equally efficient even with reduced exposure times. WOW-culture of zona-free versus zona-intact zygotes were not different in either blastocyst yield (44.6 +/- 2.4% versus 51.8 +/- 13.5% [mean +/- SEM]) or quality (126.3 +/- 48.4 versus 119.9 +/- 32.6 total cells), and exposure of zygotes to PHA-P did not reduce blastocyst yields compared to vehicle control (40.8 +/- 11.6% versus 47.1 +/- 20.8% of cultured oocytes). Subsequent application of the optimized technique for nuclear transfer using nine different granulosa cell primary cultures (cultured in 0.5% serum for 5-12 days) generated 37.6 +/- 3.9% (11 replicates; range, 16.4-58.1%) blastocysts per successfully fused and surviving reconstructed embryo (after activation), and 33.6 +/- 3.7% blastocysts per attempted reconstructed embryo. Mean day 7 total blastocyst cell numbers from 5 clone families was 128.1 +/- 15.3. The ongoing pregnancy rate of recipients each receiving two nuclear transfer blastocysts is 3/13 (23.1%) recipients pregnant at 5 months after transfer. These results suggest that the zona-free nuclear transfer technique generates blastocysts of equivalent quantity and quality compared to conventional micromanipulation methods, requires less technical expertise, is less time consuming and can double the daily output of reconstructed embryos (even after taking into consideration the rejection of the half oocytes containing the metaphase plate).
Collapse
Affiliation(s)
- P J Booth
- Section for Reproductive Biology, Department of Animal Breeding and Genetics, Danish Institute of Agricultural Sciences, Tjele, Denmark.
| | | | | | | | | |
Collapse
|
15
|
Kühholzer B, Prather RS. Advances in livestock nuclear transfer. PROCEEDINGS OF THE SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE. SOCIETY FOR EXPERIMENTAL BIOLOGY AND MEDICINE (NEW YORK, N.Y.) 2000; 224:240-5. [PMID: 10964258 DOI: 10.1046/j.1525-1373.2000.22427.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cloning and transgenic animal production have been greatly enhanced by the development of nuclear transfer technology. In the past, genetic modification in domestic animals was not tightly controlled. With the nuclear transfer technology one can now create some domestic animals with specific genetic modifications. An ever-expanding variety of cell types have been successfully used as donors to create the clones. Both cell fusion and microinjection are successfully being used to create these animals. However, it is still not clear which stage(s) of the cell cycle for donor and recipient cells yield the greatest degree of development. While for the most part gene expression is reprogrammed in nuclear transfer embryos, all structural changes may not be corrected as evidenced by the length of the telomeres in sheep resulting from nuclear transfer. Even after these animals are created the question of "are they really clones?" arises due to mitochondrial inheritance from the donor cell versus the recipient oocyte. This review discusses these issues as they relate to livestock.
Collapse
Affiliation(s)
- B Kühholzer
- Animal Science Research Center, University of Missouri-Columbia, Missouri 65211-5300, USA
| | | |
Collapse
|
16
|
Dinnyés A, Hirao Y, Nagai T. Parthenogenetic Activation of Porcine Oocytes by Electric Pulse and/or Butyrolactone I Treatment. ACTA ACUST UNITED AC 1999; 1:209-16. [PMID: 16218821 DOI: 10.1089/15204559950019843] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The goal of the present research was to study the parthenogenetic activation of porcine oocytes following treatment with the specific cyclin-dependent kinase inhibitor butyrolactone I (BL I). In Experiment I, the effective dose of BL I was determined by the rates of the subsequent pronuclear formation in oocytes after the activation. In Experiment II, BL I was further tested alone or in combination with an electric pulse. The efficiency of the various treatments to induce activation and parthenogenetic development was examined. In Experiment III parthenogenetic development of activated oocytes in two different media was compared. Cleavage and blastocyst developmental rates were examined, and number of cells in the blastocysts was determined. Our results indicate that, in pig, the optimal activation dose for BL I was 150 microM; a combined electrical and BL I treatment resulted in superior cleavage rates compared to an electric pulse, 150 microM of BL I, or 200 microM of BL I alone (74%, 60%, 41%, and 42%, respectively; P < 0.05); and the rate of parthenogenetic development of activated oocytes to the blastocyst stage in mNCSU37 medium was significantly higher than that in Whitten's medium (59% vs. 5%, P < 0.05) and the resulting day-6 blastocysts had higher cell numbers (35.5 +/- 14.1 vs. 19.5 +/- 2.5). This activation protocol might be useful in porcine nuclear transfer experiments and for the generation of parthenogenetic fetuses.
Collapse
Affiliation(s)
- A Dinnyés
- Department of Animal Production, Tohoku National Agricultural Experiment Station, Shimo-kuriyagawa, Morioka, Iwate, 020-0198, Japan.
| | | | | |
Collapse
|