1
|
Vazquez-Avendaño JR, Cortez-Romero C, Bravo-Vinaja Á, Ambríz-García DA, Trejo-Córdova A, Navarro-Maldonado MDC. Reproduction of Sheep through Nuclear Transfer of Somatic Cells: A Bibliometric Approach. Animals (Basel) 2023; 13:1839. [PMID: 37889773 PMCID: PMC10251971 DOI: 10.3390/ani13111839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 05/26/2023] [Accepted: 05/28/2023] [Indexed: 10/29/2023] Open
Abstract
Somatic cell nuclear transfer (SCNT) is a reproductive biotechnology with great potential in the reproduction of different species of zootechnical interest, including sheep. This study aimed to carry out a bibliometric analysis of scientific papers published on the application of SCNT in sheep reproduction during the period 1997-2023. The search involved the Science Citation Index Expanded and Social Sciences Citation Index databases of the main collection of the Web of Sciences with different descriptors. A total of 124 scientific papers were analyzed for different bibliometric indicators using the VOSviewer software. Since 2001, the number of SCNT-related papers that have been published concerning sheep reproduction has increased and it has fluctuated in ensuing years. The main authors, research groups, institutions, countries, papers, and journals with the highest number of papers related to the application of SCNT in sheep reproduction were identified, as well as the topics that address the research papers according to the terms: somatic cell, embryo, oocyte, gene expression, SCNT, and sheep.
Collapse
Affiliation(s)
- José Roberto Vazquez-Avendaño
- Doctorado en Ciencias Biológicas y de la Salud, Universidad Autónoma Metropolitana, Ciudad de México C.P. 3855, Mexico;
- Department of Biology of Reproduction, Division of Biological and Health Sciences, Universidad Autónoma Metropolitana, Unidad Iztapalapa, Ciudad de México C.P. 09310, Mexico; (D.A.A.-G.); (A.T.-C.)
| | - César Cortez-Romero
- Program in Genetic Resources and Productivity-Livestock, Campus Montecillo, Colegio de Postgraduados, Montecillo, Texcoco C.P. 56264, Mexico;
- Program in Innovation in Natural Resources Management, Campus San Luis Potosí, Colegio de Postgraduados, Salinas de Hidalgo, San Luis Potosí C.P. 78600, Mexico;
| | - Ángel Bravo-Vinaja
- Program in Innovation in Natural Resources Management, Campus San Luis Potosí, Colegio de Postgraduados, Salinas de Hidalgo, San Luis Potosí C.P. 78600, Mexico;
| | - Demetrio Alonso Ambríz-García
- Department of Biology of Reproduction, Division of Biological and Health Sciences, Universidad Autónoma Metropolitana, Unidad Iztapalapa, Ciudad de México C.P. 09310, Mexico; (D.A.A.-G.); (A.T.-C.)
| | - Alfredo Trejo-Córdova
- Department of Biology of Reproduction, Division of Biological and Health Sciences, Universidad Autónoma Metropolitana, Unidad Iztapalapa, Ciudad de México C.P. 09310, Mexico; (D.A.A.-G.); (A.T.-C.)
| | - María del Carmen Navarro-Maldonado
- Department of Biology of Reproduction, Division of Biological and Health Sciences, Universidad Autónoma Metropolitana, Unidad Iztapalapa, Ciudad de México C.P. 09310, Mexico; (D.A.A.-G.); (A.T.-C.)
| |
Collapse
|
2
|
Yu T, Meng R, Song W, Sun H, An Q, Zhang C, Zhang Y, Su J. ZFP57 regulates DNA methylation of imprinted genes to facilitate embryonic development of somatic cell nuclear transfer embryos in Holstein cows. J Dairy Sci 2022; 106:769-782. [DOI: 10.3168/jds.2022-22427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Accepted: 08/17/2022] [Indexed: 11/17/2022]
|
3
|
Uh K, Hay A, Chen P, Reese E, Lee K. Design of novel oocyte activation methods: The role of zinc. Biol Reprod 2021; 106:264-273. [PMID: 34935887 DOI: 10.1093/biolre/ioab235] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Revised: 12/13/2021] [Accepted: 12/15/2021] [Indexed: 11/15/2022] Open
Abstract
Oocyte activation occurs at the time of fertilization and is a series of cellular events initiated by intracellular Ca2+ increases. Consequently, oocytes are alleviated from their arrested state in meiotic metaphase II (MII), allowing for the completion of meiosis. Oocyte activation is also an essential step for somatic cell nuclear transfer (SCNT) and an important tool to overcome clinical infertility. Traditional artificial activation methods aim to mimic the intracellular Ca2+ changes which occur during fertilization. Recent studies emphasize the importance of cytoplasmic Zn2+ on oocyte maturation and the completion of meiosis, thus suggesting artificial oocyte activation approaches that are centered around the concentration of available Zn2+in oocytes. Depletion of intracellular Zn2+ in oocytes with heavy metal chelators leads to successful oocyte activation in the absence of cellular Ca2+ changes, indicating that successful oocyte activation does not always depends on intracellular Ca2+ increases. Current findings lead to new approaches to artificially activate mammalian oocytes by reducing available Zn2+ contents, and the approaches improve the outcome of oocyte activation when combined with existing Ca2+ based oocyte activation methods. Here, we review the important role of Ca2+ and Zn2+ in mammalian oocyte activation and development of novel oocyte activation approaches based on Zn2+ availability.
Collapse
Affiliation(s)
- Kyungjun Uh
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65201, USA
| | - Alayna Hay
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Paula Chen
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65201, USA
| | - Emily Reese
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65201, USA
| | - Kiho Lee
- Division of Animal Sciences, University of Missouri, Columbia, MO, 65201, USA
| |
Collapse
|
4
|
Meng L, Hu H, Liu Z, Zhang L, Zhuan Q, Li X, Fu X, Zhu S, Hou Y. The Role of Ca 2 + in Maturation and Reprogramming of Bovine Oocytes: A System Study of Low-Calcium Model. Front Cell Dev Biol 2021; 9:746237. [PMID: 34765601 PMCID: PMC8577575 DOI: 10.3389/fcell.2021.746237] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Accepted: 09/28/2021] [Indexed: 12/22/2022] Open
Abstract
[Ca2+]i is essential for mammalian oocyte maturation and early embryonic development, as those processes are Ca2+ dependent. In the present study, we investigated the effect of [Ca2+]i on in vitro maturation and reprogramming of oocytes in a lower calcium model of oocyte at metaphase II (MII) stage, which was established by adding cell-permeant Ca2+ chelator BAPTA-AM to the maturation medium. Results showed that the extrusion of the first polar body (PB1) was delayed, and oocyte cytoplasmic maturation, including mitochondrial and endoplasmic reticulum distribution, was impaired in lower calcium model. The low-calcium-model oocytes presented a poor developmental phenotype of somatic cell nuclear transfer (SCNT) embryos at the beginning of activation of zygotic genome. At the same time, oxidative stress and apoptosis were observed in the low-calcium-model oocytes; subsequently, an RNA-seq analysis of the lower-calcium-model oocytes screened 24 genes responsible for the poor oocyte reprogramming, and six genes (ID1, SOX2, DPPA3, ASF1A, MSL3, and KDM6B) were identified by quantitative PCR. Analyzing the expression of these genes is helpful to elucidate the mechanisms of [Ca2+]i regulating oocyte reprogramming. The most significant difference gene in this enriched item was ID1. Our results showed that the low calcium might give rise to oxidative stress and apoptosis, resulting in impaired maturation of bovine oocytes and possibly affecting subsequent reprogramming ability through the reduction of ID1.
Collapse
Affiliation(s)
- Lin Meng
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Hongmei Hu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China.,Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhiqiang Liu
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Luyao Zhang
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Qingrui Zhuan
- Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Xue Li
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xiangwei Fu
- Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Shien Zhu
- Key Laboratory of Animal Genetics, Breeding and Reproduction, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Yunpeng Hou
- State Key Laboratory of Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| |
Collapse
|
5
|
McLean ZL, Appleby SJ, Fermin LM, Henderson HV, Wei J, Wells DN, Oback B. Controlled Cytoplast Arrest and Morula Aggregation Enhance Development, Cryoresilience, and In Vivo Survival of Cloned Sheep Embryos. Cell Reprogram 2021; 23:14-25. [PMID: 33529123 DOI: 10.1089/cell.2020.0078] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Zona-free somatic cell transfer (SCT) and embryo aggregation increase throughput and efficiency of cloned embryo and offspring production, respectively, but both approaches have not been widely adopted. Cloning efficiency is further improved by cell cycle coordination between the interphase donor cell and metaphase-arrested recipient cytoplast. This commonly involves inclusion of caffeine and omission of calcium to maintain high mitotic cyclin-dependent kinase activity and low calcium levels, respectively, in the nonactivated cytoplast. The aim of our study was to integrate these various methodological improvements into a single work stream that increases sheep cloning success. We show that omitting calcium during zona-free SCT improved blastocyst development from 6% to 13%, while caffeine treatment reduced spontaneous oocyte activation from 17% to 8%. In a retrospective analysis, morula aggregation produced high morphological quality blastocysts with better in vivo survival to term than nonaggregated controls (15% vs. 9%), particularly after vitrification (14% vs. 0%). By combining cytoplast cell cycle control with zona-free embryo reconstruction and aggregation, this novel SCT protocol maximizes the benefits of vitrification by producing more cryoresilient blastocysts. The presented cloning methodology is relatively easy to operate and further increases throughput and efficiency of cloned embryo and offspring production. Integration of additional reprogramming steps or alternate donor cells is straightforward, providing a flexible workflow that can be adapted to changing experimental requirements.
Collapse
Affiliation(s)
- Zachariah Louis McLean
- Reproduction, AgResearch, Ruakura Research Centre, Hamilton, New Zealand
- Applied Translational Research Group and Centre for Brain Research, School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - Sarah Jane Appleby
- Reproduction, AgResearch, Ruakura Research Centre, Hamilton, New Zealand
- Department of Molecular Medicine and Pathology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| | | | | | - Jingwei Wei
- Reproduction, AgResearch, Ruakura Research Centre, Hamilton, New Zealand
| | - David Norman Wells
- Reproduction, AgResearch, Ruakura Research Centre, Hamilton, New Zealand
| | - Björn Oback
- Reproduction, AgResearch, Ruakura Research Centre, Hamilton, New Zealand
- Department of Molecular Medicine and Pathology, School of Medical Sciences, University of Auckland, Auckland, New Zealand
| |
Collapse
|
6
|
Chen HL, Cheng JY, Yang YF, Li Y, Jiang XH, Yang L, Wu L, Shi M, Liu B, Duan J, Li X, Li QW. Phospholipase C inhibits apoptosis of porcine oocytes cultured in vitro. J Cell Biochem 2020; 121:3547-3559. [DOI: 10.1002/jcb.29636] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Accepted: 12/09/2019] [Indexed: 11/08/2022]
Affiliation(s)
- Hua Li Chen
- College of Animal Science and TechnologyNorthwest A&F UniversityYangling Shaanxi China
| | - Jian Yong Cheng
- College of Animal Science and TechnologyNorthwest A&F UniversityYangling Shaanxi China
| | - You Fu Yang
- College of Animal Science and TechnologyNorthwest A&F UniversityYangling Shaanxi China
| | - Yuan Li
- College of Animal Science and TechnologyNorthwest A&F UniversityYangling Shaanxi China
| | - Xiao Han Jiang
- College of Animal Science and TechnologyNorthwest A&F UniversityYangling Shaanxi China
| | - Li Yang
- College of Animal Science and TechnologyNorthwest A&F UniversityYangling Shaanxi China
| | - Lin Wu
- College of Animal Science and TechnologyNorthwest A&F UniversityYangling Shaanxi China
| | - Meihong Shi
- College of Animal Science and TechnologyNorthwest A&F UniversityYangling Shaanxi China
| | - Boyang Liu
- College of Animal Science and TechnologyNorthwest A&F UniversityYangling Shaanxi China
| | - Jiaxin Duan
- College of Animal Science and TechnologyNorthwest A&F UniversityYangling Shaanxi China
| | - Xiaoya Li
- College of Animal Science and TechnologyNorthwest A&F UniversityYangling Shaanxi China
| | - Qing Wang Li
- College of Animal Science and TechnologyNorthwest A&F UniversityYangling Shaanxi China
| |
Collapse
|
7
|
Chang HY, Xie RX, Zhang L, Fu LZ, Zhang CT, Chen HH, Wang ZQ, Zhang Y, Quan FS. Overexpression of miR-101-2 in donor cells improves the early development of Holstein cow somatic cell nuclear transfer embryos. J Dairy Sci 2019; 102:4662-4673. [PMID: 30879805 DOI: 10.3168/jds.2018-15072] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 01/22/2019] [Indexed: 12/17/2022]
Abstract
Accumulating studies have suggested that microRNA play a part in regulating multiple cellular processes, such as cell proliferation, apoptosis, the cell cycle, and embryo development. This study explored the effects of miR-101-2 on donor cell physiological status and the development of Holstein cow somatic cell nuclear transfer (SCNT) embryos in vitro. Holstein cow bovine fetal fibroblasts (BFF) overexpressing miR-101-2 were used as donor cells to perform SCNT; then, cleavage rate, blastocyst rate, inner cell mass-to-trophectoderm ratio, and the expression of some development- and apoptosis-related genes in different groups were analyzed. The miR-101-2 suppressed the expression of inhibitor of growth protein 3 (ING3) at mRNA and protein levels, expedited cell proliferation, and decreased apoptosis in BFF, suggesting that ING3, a target gene of miR-101-2, is a potential player in this process. Moreover, by utilizing donor cells overexpressing miR-101-2, the development of bovine SCNT embryos in vitro was significantly enhanced; the apoptotic rate in SCNT blastocysts was reduced, and the inner cell mass-to-trophectoderm ratio and SOX2, POU5F1, and BCL2L1 expression significantly increased, whereas BAX and ING3 expression decreased. Collectively, these findings suggest that miR-101-2 promotes BFF proliferation and vitality, reduces their apoptosis, and improves the early development of SCNT embryos.
Collapse
Affiliation(s)
- H Y Chang
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China; College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - R X Xie
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China; College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - L Zhang
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China; College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - L Z Fu
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China; College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - C T Zhang
- Animal Husbandry and Veterinary Station of Xining, Xining 810003, Qinghai, China
| | - H H Chen
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China; College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Z Q Wang
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China; College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China
| | - Y Zhang
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China; College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China.
| | - F S Quan
- Key Laboratory of Animal Biotechnology of the Ministry of Agriculture, Northwest A&F University, Yangling 712100, Shaanxi, China; College of Veterinary Medicine, Northwest A&F University, Yangling 712100, Shaanxi, China.
| |
Collapse
|
8
|
Qiu X, Xiao X, Martin GB, Li N, Ling W, Wang M, Li Y. Strategies for improvement of cloning by somatic cell nuclear transfer. ANIMAL PRODUCTION SCIENCE 2019. [DOI: 10.1071/an17621] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Somatic cell nuclear transfer (SCNT) is a powerful tool that is being applied in a variety of fields as diverse as the cloning and production of transgenic animals, rescue of endangered species and regenerative medicine. However, cloning efficiency is still very low and SCNT embryos generally show poor developmental competency and many abnormalities. The low efficiency is probably due to incomplete reprogramming of the donor nucleus and most of the developmental problems are thought to be caused by epigenetic defects. Applications of SCNT will, therefore, depend on improvements in the efficiency of production of healthy clones. This review has summarised the progress and strategies that have been used to make improvements in various animal species, especially over the period 2010–2017, including strategies based on histone modification, embryo aggregation and mitochondrial function. There has been considerable investiagation into the mechanisms that underpin each strategy, helping us better understand the nature of genomic reprogramming and nucleus–cytoplasm interactions.
Collapse
|
9
|
Cordova A, King WA, Mastromonaco GF. Choosing a culture medium for SCNT and iSCNT reconstructed embryos: from domestic to wildlife species. JOURNAL OF ANIMAL SCIENCE AND TECHNOLOGY 2017; 59:24. [PMID: 29152322 PMCID: PMC5680814 DOI: 10.1186/s40781-017-0149-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 08/03/2017] [Accepted: 10/23/2017] [Indexed: 12/16/2022]
Abstract
Over the past decades, in vitro culture media have been developed to successfully support IVF embryo growth in a variety of species. Advanced reproductive technologies, such as somatic cell nuclear transfer (SCNT), challenge us with a new type of embryo, with special nutritional requirements and altered physiology under in vitro conditions. Numerous studies have successfully reconstructed cloned embryos of domestic animals for biomedical research and livestock production. However, studies evaluating suitable culture conditions for SCNT embryos in wildlife species are scarce (for both intra- and interspecies SCNT). Most of the existing studies derive from previous IVF work done in conventional domestic species. Extrapolation to non-domestic species presents significant challenges since we lack information on reproductive processes and embryo development in most wildlife species. Given the challenges in adapting culture media and conditions from IVF to SCNT embryos, developmental competence of SCNT embryos remains low. This review summarizes research efforts to tailor culture media to SCNT embryos and explore the different outcomes in diverse species. It will also consider how these culture media protocols have been extrapolated to wildlife species, most particularly using SCNT as a cutting-edge technical resource to assist in the preservation of endangered species.
Collapse
Affiliation(s)
- A Cordova
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario Canada.,Reproductive Physiology, Toronto Zoo, Scarborough, Ontario Canada
| | - W A King
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario Canada
| | - G F Mastromonaco
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario Canada.,Reproductive Physiology, Toronto Zoo, Scarborough, Ontario Canada
| |
Collapse
|
10
|
Recipient of the 2015 IETS Pioneer Award: Keith Henry Stockman Campbell, PhD. Reprod Fertil Dev 2014; 27:xxvi-xxviii. [PMID: 25472414 DOI: 10.1071/rdv27n1_pa2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
|
11
|
Bohrer RC, Che L, Gonçalves PBD, Duggavathi R, Bordignon V. Phosphorylated histone H2A.x in porcine embryos produced by IVF and somatic cell nuclear transfer. Reproduction 2013; 146:325-33. [PMID: 23858475 DOI: 10.1530/rep-13-0271] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
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+Sr(2+)). 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.
Collapse
Affiliation(s)
- Rodrigo C Bohrer
- Department of Animal Science, McGill University, 21111 Lakeshore Road, Ste-Anne-de-Bellevue, Quebec, Canada H9X 3V9
| | | | | | | | | |
Collapse
|