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Kij-Mitka B, Kochan J, Bugno-Poniewierska M, Cernohorska H, Kubickova S, Kowal W, Prochowska S, Niżański W. Analysis of morphological disorders and ploidy in domestic cat blastocysts. Theriogenology 2022; 186:114-121. [DOI: 10.1016/j.theriogenology.2022.03.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/28/2022] [Accepted: 03/28/2022] [Indexed: 11/25/2022]
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2
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Zhao Q, Qiu YG, Tian JT, Wang CS, An TZ. Porcine Cloned Embryos Reconstructed with the Cell Nuclei of Tetraploid M-phase Fibroblast Cells Can Restore Normal Diploidy at the Blastocyst Stage. Anim Biotechnol 2017; 28:182-188. [PMID: 27854178 DOI: 10.1080/10495398.2016.1249794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
The cell cycle of donor cells as a major factor that affects cloning efficiency remains debatable. G2/M phase cells as a donor can successfully produce cloned animals, but a minimal amount is known regarding nuclear remodeling events. In this study, porcine fetal fibroblasts (PFFs) were carefully synchronized at G1 or M phase as donor cells. Most of the cloned embryos reconstructed from PFFs at G1 (G1-embryos) or M (M-embryos) phase formed a pronucleus-like nucleus (PN) within 6-h post fusion (hpf), but the M-embryos formed PN earlier than the G1-embryos did. Moreover, 77.4% of the M-embryos formed two PNs, whereas the G1-embryos formed a single PN. The rate of extrusion of polar body-like structures by the M-embryos was significantly lower than that extruded by the G1-embryos (26.3% vs. 37.1%, P < 0.05), and DNA synthesis in most embryos in both groups was initiated at 9-12 hpf. Most of the M-embryos were octoploid before the first cleavage. Furthermore, 81.25% of the blastomeres of blastocysts developed from the M-embryos showed abnormal ploidy compared with those developed from the G1-embryos (22.55%). However, some of the blastomeres remained diploid in all the M-embryos tested. A portion of the blastomeres restored normal diploidy in some of the M-embryos at the blastocyst stage. This finding provides an explanation for M-embryos developing to term.
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Affiliation(s)
- Q Zhao
- a College of Life Science , Northeast Forestry University , Harbin , P. R. China
| | - Y G Qiu
- a College of Life Science , Northeast Forestry University , Harbin , P. R. China
| | - J T Tian
- b Department of Cardiology , The 2nd Affiliated Hospital of Harbin Medical University, The Key Laboratory of Myocardial Ischemia, Chinese Ministry of Education , Harbin , P. R. China
| | - C S Wang
- a College of Life Science , Northeast Forestry University , Harbin , P. R. China
| | - T Z An
- a College of Life Science , Northeast Forestry University , Harbin , P. R. China
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3
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Perkel KJ, Tscherner A, Merrill C, Lamarre J, Madan P. The ART of selecting the best embryo: A review of early embryonic mortality and bovine embryo viability assessment methods. Mol Reprod Dev 2015; 82:822-38. [PMID: 26184077 DOI: 10.1002/mrd.22525] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2014] [Accepted: 07/10/2015] [Indexed: 12/14/2022]
Abstract
Animal reproductive biotechnology is continually evolving. Significant advances have been made in our understanding of early embryonic mortality and embryo development in domestic animals, which has improved the selection and success of in vitro technologies. Yet our knowledge is still relatively limited such that identifying a single embryo with the highest chance of survival and development for transfer remains challenging. While invasive methods such as embryo biopsy can provide useful information regarding the genetic status of the embryos, morphological assessment remains the most common evaluation. A recent shift, however, favors alternative, adjunct approaches for non-invasive assessment of an embryo's viability and developmental potential. Various analytical techniques have facilitated the evaluation of cellular health through the metabolome, the assessment of end products of cellular metabolism, or by analyzing spent media for small RNAs. This review discusses the application of noninvasive approaches for ascertaining the health and viability of in vitro-produced bovine embryos. A comparative analysis of noninvasive techniques for embryo assessment currently being investigated in cattle and humans is also discussed.
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Affiliation(s)
- Kayla J Perkel
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Allison Tscherner
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Casandra Merrill
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Jonathan Lamarre
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
| | - Pavneesh Madan
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
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Li R, Wu H, Zhuo WW, Mao QF, Lan H, Zhang Y, Hua S. Astaxanthin Normalizes Epigenetic Modifications of Bovine Somatic Cell Cloned Embryos and Decreases the Generation of Lipid Peroxidation. Reprod Domest Anim 2015; 50:793-9. [DOI: 10.1111/rda.12589] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 07/11/2015] [Indexed: 01/26/2023]
Affiliation(s)
- R Li
- College of Veterinary Medicine; Northwest A&F University; Yangling Shaanxi Province China
| | - H Wu
- College of Veterinary Medicine; Northwest A&F University; Yangling Shaanxi Province China
| | - WW Zhuo
- College of Veterinary Medicine; Northwest A&F University; Yangling Shaanxi Province China
| | - QF Mao
- College of Veterinary Medicine; Northwest A&F University; Yangling Shaanxi Province China
| | - H Lan
- College of Veterinary Medicine; Northwest A&F University; Yangling Shaanxi Province China
| | - Y Zhang
- College of Veterinary Medicine; Northwest A&F University; Yangling Shaanxi Province China
| | - S Hua
- College of Veterinary Medicine; Northwest A&F University; Yangling Shaanxi Province China
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Felmer R, Arias ME. Activation treatment of recipient oocytes affects the subsequent development and ploidy of bovine parthenogenetic and somatic cell nuclear transfer (SCNT) embryos. Mol Reprod Dev 2015; 82:441-9. [DOI: 10.1002/mrd.22492] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 04/13/2015] [Indexed: 12/11/2022]
Affiliation(s)
- R. Felmer
- Laboratory of Reproduction; Centre of Reproductive Biotechnology (CEBIOR-BIOREN), Universidad de La Frontera; Temuco Chile
- Faculty of Agriculture and Forestry; Department of Agricultural Sciences and Natural Resources; Universidad de La Frontera; Temuco Chile
| | - M. E. Arias
- Laboratory of Reproduction; Centre of Reproductive Biotechnology (CEBIOR-BIOREN), Universidad de La Frontera; Temuco Chile
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6
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Pers-Kamczyc E, Pawlak P, Rubes J, Lechniak D. Early cleaved bovine embryos show reduced incidence of chromosomal aberrations and higher developmental potential on day 4.5 post-insemination. Reprod Domest Anim 2012; 47:899-906. [PMID: 22304363 DOI: 10.1111/j.1439-0531.2012.01987.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The present study aimed to investigate whether the timing of the first zygotic cleavage (FZC) influences the speed of embryo development expressed by the total cell count and the rate of chromosomally aberrant embryos. Bovine embryos were produced in vitro and divided into two categories according to the timing of FZC: early cleavers (at 30 hpi; EC) and non-early cleavers (at 48 hpi; NEC). On day 4.5 pi, embryos were grouped into three classes depending on the number of blastomeres: delayed (<8 BL), normal (8-16 BL) and advanced (>16 BL). We applied fluorescence in situ hybridization (FISH) with probes for bovine chromosomes 6 and X. The only form of chromosomal imbalance observed was mixoploidy [(2n/3n; 2n/4n); 19.9%, 54/271]. Early cleavers were less often chromosomally unbalanced (13.9%, 20/144) than their NEC counterparts (26.7%, 34/127). Among embryos developing at a normal speed, the NEC embryos were more often abnormal (NEC 20/80; EC 10/79; p < 0.05). The advanced embryos were not observed among the NEC category, whereas such embryos from EC category displayed no chromosomal aberrations. The majority of embryos arrested at the 8 BL stage were of NEC category and were carriers of chromosomally abnormal blastomeres. With regard to embryonic sex, we demonstrated that although males dominate among bovine embryos developing in vitro, the incidence of mixoploidy was equal for both sexes. It can be suggested that a good-quality bovine embryo is usually an early cleaver that develops at higher speed and contains less aberrant cells. The present study also confirmed the usefulness of the FZC as a marker of embryo quality by demonstrating a significantly lower incidence of aberrations in early embryos.
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Affiliation(s)
- E Pers-Kamczyc
- Department of Genetics and Animal Breeding, Poznan University of Life Sciences, Poznan, Poland
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7
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Favetta L, Villagómez D, Iannuzzi L, Di Meo G, Webb A, Crain S, King W. Disorders of Sexual Development and Abnormal Early Development in Domestic Food-Producing Mammals: The Role of Chromosome Abnormalities, Environment and Stress Factors. Sex Dev 2012; 6:18-32. [DOI: 10.1159/000332754] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
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8
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Moawad AR, Choi I, Zhu J, Campbell KH. Ovine Oocytes Vitrified at Germinal Vesicle Stage as Cytoplast Recipients for Somatic Cell Nuclear Transfer (SCNT). Cell Reprogram 2011; 13:289-96. [DOI: 10.1089/cell.2010.0089] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
Affiliation(s)
- Adel R. Moawad
- Animal Development and Biotechnology Group, Division of Animal Sciences, School of Biosciences, University of Nottingham, Loughborough, LE12 5RD, United Kingdom
| | - Inchul Choi
- Animal Development and Biotechnology Group, Division of Animal Sciences, School of Biosciences, University of Nottingham, Loughborough, LE12 5RD, United Kingdom
| | - Jie Zhu
- Animal Development and Biotechnology Group, Division of Animal Sciences, School of Biosciences, University of Nottingham, Loughborough, LE12 5RD, United Kingdom
| | - Keith H.S. Campbell
- Animal Development and Biotechnology Group, Division of Animal Sciences, School of Biosciences, University of Nottingham, Loughborough, LE12 5RD, United Kingdom
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Jeon BG, Betts DH, King WA, Rho GJ. In Vitro Developmental Potential of Nuclear Transfer Embryos Cloned with Enucleation Methods using Pre-denuded Bovine Oocytes. Reprod Domest Anim 2011; 46:1035-42. [DOI: 10.1111/j.1439-0531.2011.01781.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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10
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Pawlak P, Pers-Kamczyc E, Renska N, Kubickova S, Lechniak D. Disturbances of nuclear maturation in BCB positive oocytes collected from peri-pubertal gilts. Theriogenology 2011; 75:832-40. [DOI: 10.1016/j.theriogenology.2010.10.025] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2010] [Revised: 09/30/2010] [Accepted: 10/13/2010] [Indexed: 11/28/2022]
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11
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Garcia-Herreros M, Carter TF, Villagómez DAF, MacAulay AD, Rath D, King WA, Lonergan P. Incidence of chromosomal abnormalities in bovine blastocysts derived from unsorted and sex-sorted spermatozoa. Reprod Fertil Dev 2010; 22:1272-8. [DOI: 10.1071/rd10052] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2010] [Accepted: 06/28/2010] [Indexed: 01/11/2023] Open
Abstract
The aim of the present study was to examine the incidence of chromosomal abnormalities in bovine blastocysts produced by IVF with unsorted, X-sorted or Y-sorted spermatozoa. In Experiment 1, individual blastocysts were processed to examine the incidence of mixoploidy using fluorescent in situ hybridisation. Overall, 80% (44/55) of blastocysts were mixoploid (10/15, 14/15 and 20/25 for X-sorted, Y-sorted and unsorted spermatozoa, respectively; P > 0.05). However, the prevalence of abnormal XY chromosome complements was relatively low in all groups; on average, only a small fraction of the total nuclei per embryo appeared polyploid (1.64%, 5.62% and 6.0% for X-sorted, Y-sorted and unsorted spermatozoa, respectively). Interestingly, 20% (5/25) of blastocysts derived from unsorted spermatozoa were found to be chimeric (XX/XY). In Experiment 2, chimeric embryos were detected among the blastocysts derived from two of five sires tested. In addition, one chimeric blastocyst was detected among nine in vivo-derived blastocysts obtained following AI. In conclusion, based on the results of the present study, the incidence of chromosomal abnormalities did not different between blastocysts derived from sex-sorted or unsorted spermatozoa. In addition, the occurrence of mixed sex chimeras was not limited to a single sire and was not unique to blastocysts derived from IVF.
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12
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Interspecies somatic cell nucleus transfer with porcine oocytes as recipients: A novel bioassay system for assessing the competence of canine somatic cells to develop into embryos. Theriogenology 2009; 72:549-59. [DOI: 10.1016/j.theriogenology.2009.04.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2009] [Revised: 03/14/2009] [Accepted: 04/08/2009] [Indexed: 01/08/2023]
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13
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Lee E, Kim JH, Park SM, Jeong YI, Lee JY, Park SW, Choi J, Kim HS, Jeong YW, Kim S, Hyun SH, Hwang WS. The analysis of chromatin remodeling and the staining for DNA methylation and histone acetylation do not provide definitive indicators of the developmental ability of inter-species cloned embryos. Anim Reprod Sci 2008; 105:438-50. [DOI: 10.1016/j.anireprosci.2007.12.021] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2007] [Revised: 11/27/2007] [Accepted: 12/12/2007] [Indexed: 10/22/2022]
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14
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King WA. Chromosome variation in the embryos of domestic animals. Cytogenet Genome Res 2008; 120:81-90. [PMID: 18467828 DOI: 10.1159/000118743] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2007] [Indexed: 12/30/2022] Open
Abstract
Chromosome abnormalities in the embryos of domestic animals are mostly eliminated during development. De novo chromosome abnormalities in the embryos of domestic animals have been detected in a larger proportion of embryos produced by in vitro fertilization and somatic cell nuclear transfer than in those produced by natural mating or artificial insemination. The increased incidence of abnormalities in embryos produced in vitro provides evidence for an influence of the embryo production procedures on chromosome stability. Research strategies involving cytogenetics, molecular biology and reproductive biotechnologies hold the promise of yielding insight into the mechanisms underlying chromosome instability in embryos and the impact of the in vitro environment on the chromosome make-up of embryos.
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Affiliation(s)
- W A King
- Department of Biomedical Sciences, University of Guelph, Guelph, ON, Canada.
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15
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Lechniak D, Pers-Kamczyc E, Pawlak P. Timing of the first zygotic cleavage as a marker of developmental potential of mammalian embryos. Reprod Biol 2008; 8:23-42. [DOI: 10.1016/s1642-431x(12)60002-3] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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16
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Alexander B, Coppola G, Perrault SD, Peura TT, Betts DH, King WA. Telomere length status of somatic cell sheep clones and their offspring. Mol Reprod Dev 2008; 74:1525-37. [PMID: 17455196 DOI: 10.1002/mrd.20735] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This study was carried out to determine the telomere length status of sheep clones and their offspring, and to examine telomere dynamics and chromosomal abnormalities in culture propagated donor cells. Skin samples were collected from somatic cell nuclear transfer-derived sheep clones, and three of their progeny generated by natural mating. Samples were collected from control animals (n = 35), spanning in age from 1 month to 36 months of age. Genomic DNA was extracted from cell/tissue samples and their telomere lengths were assessed by terminal restriction fragment (TRF) analysis. Results revealed: that (a) sheep clones derived from cultured somatic cells have shortened telomere lengths compared to age-matched controls; (b) the offspring derived from natural mating between clones had normal telomere lengths compared to their age-matched counterparts; and donor cell cultures beyond 20 population doublings had significantly (P < 0.05) shortened telomeres and exhibited a higher numerical and structural chromosomal abnormalities.
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Affiliation(s)
- Basil Alexander
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada
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18
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Lechniak D, Warzych E, Pers-Kamczyc E, Sosnowski J, Antosik P, Rubes J. Gilts and sows produce similar rate of diploid oocytes in vitro whereas the incidence of aneuploidy differs significantly. Theriogenology 2007; 68:755-62. [PMID: 17628654 DOI: 10.1016/j.theriogenology.2007.06.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2007] [Revised: 05/22/2007] [Accepted: 06/06/2007] [Indexed: 10/23/2022]
Abstract
Oocytes derived from prepubertal gilts show reduced developmental competence when compared to oocytes collected from adult sows. Therefore, the aim of the study was to investigate whether gilts (4-5 months old) and adult sows (average age 3.5 years) of the same breed (Polish Landrace x Polish Large White crossbred) differ with regard to the rate of chromosomally unbalanced oocytes after IVM. COCs derived from individual pairs of slaughterhouse ovaries were matured in vitro and analyzed cytogenetically by conventional staining (Giemsa) and FISH methods (probes corresponding to centromeric regions of pig chromosomes 1 and 10). Altogether, 72 females (31 sows, 41 gilts) and 430 secondary oocytes (194 and 236 oocytes of sows and gilts, respectively) were investigated. Cytogenetic analysis revealed diploid (Giemsa, FISH) and aneuploid (FISH) spreads. The incidence of diploid oocytes was similar for sows (26.0%) and gilts (24.5%) whereas the rate of aneuploid oocytes (nullisomic/disomic) was eight times higher in gilts (10.8%) than in sows (1.3%). Diploid and aneuploid oocytes were observed in 64% of investigated females. Pig chromosome 10 was more frequently disomic/nullisomic compared to chromosome 1 suggesting, that like in human, small porcine chromosomes are often involved in the nondisjunction process. In conclusion, chromosomal imbalance significantly contributes to in vitro embryo production in the pig, since over 60% of females produced diploid or aneuploid gametes. The significantly higher rate of aneuploidy among oocytes derived from gilt ovaries may contribute to the reduced developmental competence of gametes collected from nonmature female pigs.
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Affiliation(s)
- Dorota Lechniak
- Department of Genetics and Animal Breeding, August Cieszkowski Agricultural University of Poznan, Wolynska 33, 60-637, Poznan, Poland.
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Chen N, Liow SL, Yip WY, Tan LG, Tong GQ, Ng SC. Dynamic changes in microtubules and early development of reconstructed embryos after somatic cell nuclear transfer in a non-human primate. CLONING AND STEM CELLS 2007; 8:251-8. [PMID: 17196090 DOI: 10.1089/clo.2006.8.251] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In order to improve somatic cell nuclear transfer (SCNT) efficiency and to understand cellular changes in SCNT, the dynamic changes in microtubules/DNA and early development of SCNT embryos with single or multiple pronuclei were investigated, along with activation timing on efficiency of SCNT, were studied in the Cynomolgus monkey. The confocal images showed that microtubules assembled around condensed DNA at 1h after cell injection; normal or abnormal reconstructed spindle formed at 2 h after cell injection; and reconstructed spindle separated at 2 h after activation. The results of nuclear formation showed that 61.3% of the reconstructed embryos did not form pronuclei; 19.3% formed a single nucleus, and 11.9% and 7.5% formed two and more than two reconstructed pronuclei, respectively. The cleavage and 8-cell development rates of SCNT embryos with pronuclei were significantly higher than those without pronuclei, but there was no difference in development rates among NT embryos with single, two and more then two pronuclei. Activation at 2 h after cell injection yielded more embryos with pronuclei and yielded 8-cell NT embryos more reliably than did activation at 3-4 h. In conclusion, microtubules assembled around condensed DNA at 1-2 h after cell injection, and formed a spindle at 2 h after SCNT, which separated at 2 h after activation; early development was affected by activation time, but no different between single and multiple pronuclei.
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Affiliation(s)
- Naiqing Chen
- Embryonics International, Gleneagles Hospital, Singapore
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Ortegon H, Betts DH, Lin L, Coppola G, Perrault SD, Blondin P, King WA. Genomic stability and physiological assessments of live offspring sired by a bull clone, Starbuck II. Theriogenology 2006; 67:116-26. [PMID: 17074384 DOI: 10.1016/j.theriogenology.2006.09.035] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
It appears that overt phenotypic abnormalities observed in some domestic animal clones are not transmitted to their progeny. The current study monitored Holstein heifers sired by a bull clone, Starbuck II, from weaning to puberty. Genomic stability was assessed by telomere length status and chromosomal analysis. Growth parameters, blood profiles, physical exams and reproductive parameters were assessed for 12 months (and compared to age-matched control heifers). Progeny sired by the clone bull did not differ (P>0.05) in weight, length and height compared to controls. However, progeny had lower heart rates (HR) (P=0.009), respiratory rates (RR) (P=0.007) and body temperature (P=0.03). Hematological profiles were within normal ranges and did not differ (P>0.05) between both groups. External and internal genitalia were normal and both groups reached puberty at expected ages. Progeny had two or three ovarian follicular waves per estrous cycle and serum progesterone concentrations were similar (P=0.99) to controls. Telomere lengths of sperm and blood cells from Starbuck II were not different (P>0.05) than those of non-cloned cattle; telomere lengths of progeny were not different (P>0.05) from age-matched controls. In addition, progeny had normal karyotypes in peripheral blood leukocytes compared to controls (89.1% versus 86.3% diploid, respectively). In summary, heifers sired by a bull clone had normal chromosomal stability, growth, physical, hematological and reproductive parameters, compared to normal heifers. Furthermore, they had moderate stress responses to routine handling and restraint.
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Affiliation(s)
- H Ortegon
- Department of Population Medicine, Ontario Veterinary College, University of Guelph, Ontario, Canada
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21
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Hao YH, Lai LX, Liu ZH, Im GS, Wax D, Samuel M, Murphy CN, Sutovsky P, Prather RS. Developmental competence of porcine parthenogenetic embryos relative to embryonic chromosomal abnormalities. Mol Reprod Dev 2006; 73:77-82. [PMID: 16224773 DOI: 10.1002/mrd.20358] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Parthenogenetically activated (PA) embryos exhibit delayed development, a lower blastocyst rate, and less successful development in vitro compared to in vitro fertilized (IVF) embryos. To investigate the possible mechanisms for unsuccessful parthenogenetic development, this study analyzed the chromosome abnormalities and developmental potential of porcine PA embryos. Mature oocytes were electrically activated and cultured in Porcine Zygote Medium-3 (PZM3) supplemented with 3 mg/ml BSA for 6, 7, or 8 days. The percentage of PA blastocysts was lower than that of IVF embryos on days 6 and 7 (16.4 +/- 7.4 vs. 28.7 +/- 3.7; 10.9 +/- 2.8 vs. 21.5 +/- 4.7, P < 0.05; respectively), and the PA blastocysts had significantly fewer nuclei than IVF blastocysts (23.2 +/- 1.8 vs. 29.7 +/- 0.8; 29.7 +/- 3.3 vs. 32.0 +/- 2.4, P < 0.05). The percentage of abnormal PA embryos (including embryos with condensed nuclei, arrested embryos and fragmented embryos) was higher than that of IVF embryos (PA: 52.9 +/- 12.8 vs. 16.4 +/- 7.4 on day 6), and increased with culture time (71.9 +/- 12.1 vs. 10.9 +/- 2.8. on day 7,and 75.0 +/- 22.6 vs. 12.1 +/- 2.3 on day 8, P < 0.05). The Day-6 PA blastocysts (n = 147) were divided into three classes according to the total number of nuclei (<20, 20-39, >40) and into three groups according to the morphological diameter (<150, 150-180, >180 microm). Of the haploid blastocysts, 56.1% had less than 20 nuclei, and 71.5% were less than 150 microm in diameter. Of all (114) blastocysts suitable for analysis, 55.5% displayed chromosomal abnormalities. Among chromosomal abnormalities in PA blastocysts, haploid blastocysts were most prevalent (43.6%), while polyploidy (4.4%) and mixoploidy (7.7%) embryos were less prevalent. Chromosomal abnormalities of porcine PA embryos might contribute to a higher rate of abnormal embryonic development. We suggest that a careful consideration should be given when using the blastocysts with smaller size, and establishing the optimum culture condition for PA embryos development in vitro.
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Affiliation(s)
- Yan-Hong Hao
- Division of Animal Sciences, University of Missouri-Columbia, Columbia, Missouri 65211, USA
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22
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Dai Y, Wang L, Wang H, Liu Y, Li N, Lyu Q, Keefe DL, Albertini DF, Liu L. Fate of centrosomes following somatic cell nuclear transfer (SCNT) in bovine oocytes. Reproduction 2006; 131:1051-61. [PMID: 16735544 DOI: 10.1530/rep.1.01058] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Cloning mammalians by somatic cell nuclear transfer (SCNT) remains inefficient. A majority of clones produced by SCNT fail to develop properly and of those which do survive, some exhibit early aging, premature death, tumors, and other pathologies associated with aneuploidy. Alterations of centrosomes are linked to aberrant cell cycle progression, aneuploidy, and tumorigenesis in many cell types. It remains to be determined how centrosomes are remodeled in cloned bovine embryos. We show that abnormalities in either distribution and/or number of centrosomes were evident in approximately 50% of reconstructed embryos following SCNT. Moreover, centrosome abnormalities and failed ‘pronuclear’ migration which manifested during the first cell cycle coincided with errors in spindle morphogenesis, chromosome alignment, and cytokinesis. By contrast, nuclear mitotic apparatus protein (NuMA) exhibited normal expression patterns at metaphase spindle poles and in ‘pronucleus’ during interphase. The defects in centrosome remodeling and ‘pronuclear’ migration could lead to chromosome instability and developmental failures associated with embryo production by SCNT. Addressing these fundamental problems may enhance production of normal clones.
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Affiliation(s)
- Yunping Dai
- State Key Laboratory for Agrobiotechnology, China Agricultural University, Beijing
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23
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Hiendleder S, Zakhartchenko V, Wolf E. Mitochondria and the success of somatic cell nuclear transfer cloning: from nuclear-mitochondrial interactions to mitochondrial complementation and mitochondrial DNA recombination. Reprod Fertil Dev 2006; 17:69-83. [PMID: 15745633 DOI: 10.1071/rd04115] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2004] [Accepted: 10/01/2004] [Indexed: 01/10/2023] Open
Abstract
The overall success of somatic cell nuclear transfer (SCNT) cloning is rather unsatisfactory, both in terms of efficacy and from an animal health and welfare point of view. Most research activities have concentrated on epigenetic reprogramming problems as one major cause of SCNT failure. The present review addresses the limited success of mammalian SCNT from yet another viewpoint, the mitochondrial perspective. Mitochondria have a broad range of critical functions in cellular energy supply, cell signalling and programmed cell death and, thus, affect embryonic and fetal development, suggesting that inadequate or perturbed mitochondrial functions may adversely affect SCNT success. A survey of perinatal clinical data from human subjects with deficient mitochondrial respiratory chain activity has revealed a plethora of phenotypes that have striking similarities with abnormalities commonly encountered in SCNT fetuses and offspring. We discuss the limited experimental data on nuclear-mitochondrial interaction effects in SCNT and explore the potential effects in the context of new findings about the biology of mitochondria. These include mitochondrial fusion/fission, mitochondrial complementation and mitochondrial DNA recombination, processes that are likely to be affected by and impact on SCNT cloning. Furthermore, we indicate pathways that could link epigenetic reprogramming and mitochondria effects in SCNT and address questions and perspectives for future research.
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Affiliation(s)
- Stefan Hiendleder
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center of the Ludwig-Maximilian University, D-81377 Munich, Germany.
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24
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Ock SA, Kwack DO, Lee SL, Cho SR, Jeon BG, Kumar BM, Choe SY, Rho GJ. In vitro development of bovine oocytes reconstructed with round spermatids. Theriogenology 2006; 65:1242-53. [PMID: 16165198 DOI: 10.1016/j.theriogenology.2005.08.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2005] [Revised: 08/12/2005] [Accepted: 08/14/2005] [Indexed: 11/22/2022]
Abstract
The timing between round spermatid(s) (RS) injection and oocyte activation are critical for spermatid remodeling and embryo development in intracytoplasmic injection of round spermatid (ROSI) procedure. The objective of the present study was to develop an appropriate oocyte activation method for producing developmentally competent bovine embryos reconstructed with RS. Embryos reconstructed by ROSI were compared with three activation treatments for the rates of pronuclear formation, development and ploidy. RS were isolated from bull testes by Percoll density gradients. Matured oocytes were divided into three activation groups. In Group 1, oocytes were activated with ionomycin (5 microM, 5 min) before ROSI. In Group 2, oocytes were activated with ionomycin after ROSI. In Group 3, oocytes were activated twice with ionomycin before and after ROSI. All the eggs were then incubated in cycloheximide (CHX, 10 microg/mL) for 5 h and cultured in CR1aa medium for up to 8 days. Three methods of oocyte activation were also compared for the activation and development of parthenotes. Activation rates among the groups were 70-79% and did not differ. Cleavage rates in parthenotes were significantly (P < 0.05) higher in Group 3 than in Groups 1 and 2, but blastocyst rates did not differ among the groups. In ROSI embryos, the rates of cleavage and development into blastocysts were significantly (P < 0.05) greater in Group 3 (82.3% and 13.1%) than in Groups 1 and 2 (53.7, 5.8% and 64.2, 1.7%, respectively). Ploidy analysis by examining the metaphase spreads of ROSI blastocysts displayed greater numbers of diploid chromosomal complements. These results suggest that intracytoplasmic RS injection combined with repeated ionomycin activation followed by CHX treatment is more efficient for producing developmentally competent embryos.
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Affiliation(s)
- Sun-A Ock
- College of Veterinary Medicine, Gyeongsang National University, 660-701 Chinju, Republic of Korea
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25
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Lonergan P, Fair T, Corcoran D, Evans ACO. Effect of culture environment on gene expression and developmental characteristics in IVF-derived embryos. Theriogenology 2006; 65:137-52. [PMID: 16289260 DOI: 10.1016/j.theriogenology.2005.09.028] [Citation(s) in RCA: 147] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
It is generally accepted that mammalian preimplantation embryos are sensitive to their environment and that conditions of culture can affect future growth and developmental potential both pre- and postnatally. Evidence suggests that while culture conditions during bovine in vitro embryo production can impact somewhat on the developmental potential of the early embryo, the intrinsic quality of the oocyte is the key factor determining the proportion of oocytes developing to the blastocyst stage. In addition, evidence suggests that the period of post fertilization embryo culture is the most critical period affecting blastocyst quality assessed in terms of cryotolerance, gene expression pattern and ability to establish a pregnancy. This paper reviews the current literature, with emphasis on the bovine model, demonstrating evidence for an effect of post fertilization culture environment on embryo gene expression and quality.
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Affiliation(s)
- P Lonergan
- School of Agriculture, Food Science and Veterinary Medicine, University College Dublin, Belfield, Dublin 4, Ireland
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26
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Betts DH, Perrault SD, Petrik J, Lin L, Favetta LA, Keefer CL, King WA. Telomere length analysis in goat clones and their offspring. Mol Reprod Dev 2005; 72:461-70. [PMID: 16142795 DOI: 10.1002/mrd.20371] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Incomplete epigenetic reprogramming of the donor genome is believed to be the cause behind the high rate of developmental mortality and post-natal anomalies observed in animal clones. It appears that overt phenotypic abnormalities are not transmitted to their progeny suggesting that epigenetic errors are corrected in the germline of clones. Here, we show variation in telomere lengths among Nigerian dwarf goat clones derived from different somatic cell types and that the offspring of two male clones have significantly shorter telomere lengths than age-matched noncloned animals. Telomere lengths were significantly shorter in skin biopsies of goat clones derived from adult granulosa cells compared to those measured for controls. Telomere lengths were highly variable in male goat clones reconstructed from fetal fibroblasts but their mean terminal repeat fragment (TRF) length was within normal range of normal goats. However, in the progeny of two male clones, mean TRF lengths were considerably shorter than age-matched controls for both skin and leukocyte samples. Evidence for possible inheritance of shortened telomeres was obtained by measuring telomere lengths in testicular biopsies obtained from the clones, which when compared with those from noncloned animals of a similar age were significantly shorter. The offspring exhibited telomere lengths intermediate to the TRF values obtained for their cloned fathers' and age-matched control testes. These results demonstrate that telomere length reprogramming in clones is dependent on the type of donor cell used and that the progeny of clones may inherit telomere length alterations acquired through the cloning procedure.
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Affiliation(s)
- Dean H Betts
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Ontario, Canada.
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27
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King WA, Coppola G, Alexander B, Mastromonaco G, Perrault S, Nino-Soto MI, Pinton A, Joudrey EM, Betts DH. The impact of chromosomal alteration on embryo development. Theriogenology 2005; 65:166-77. [PMID: 16280155 DOI: 10.1016/j.theriogenology.2005.09.031] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Chromosome alterations, such as those affecting telomere erosion, predictably occur with each cell division, others, which involve changes to the expression and replication of the X-chromosome occur at particular stages of development, while those that involve loss or gain of chromosomes occur in a random and so far unpredictable manner. The production of embryos in vitro and by somatic cell nuclear transfer (SCNT) has been associated with altered expression of marker genes on the X-chromosome and an increased incidence of chromosomally abnormal cells during early development. In the case of SCNT embryos chromosome abnormalities may be associated with the nuclear donor cell. Telomere rebuilding subsequent to SCNT appears to vary according to species and type of donor cell used. It is speculated that the rate of telomere erosion and incidence of chromosome abnormalities affects developmental potential of early embryos and may be potential predictors of developmental outcome.
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Affiliation(s)
- W A King
- Department of Biomedical Sciences, University of Guelph, Guelph, Ont., Canada N1G 2W1.
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28
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Jakobsen AS, Thomsen PD, Avery B. Few polyploid blastomeres in morphologically superior bovine embryos produced in vitro. Theriogenology 2005; 65:870-81. [PMID: 16115669 DOI: 10.1016/j.theriogenology.2005.06.014] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2005] [Revised: 06/28/2005] [Accepted: 06/28/2005] [Indexed: 11/19/2022]
Abstract
Morphologically inferior bovine embryos developed in vivo have been shown by karyotyping to have a higher rate of chromosomally abnormal cells than morphologically normal embryos. The objective of this study was to re-examine this finding using interphase cytogenetics. A total of 155 IVP Day 8 bovine blastocysts were graded by their morphology (excellent, good, or poor) and timing of development (hatched, expanded, or non-expanded), and afterwards analysed for chromosome abnormalities by fluorescence in situ hybridization using differentially labelled probes for chromosomes 6 and 7. The overall frequency of diploid embryos was 7%, and did not differ according to grading. Although the frequency of mixoploidy was not correlated to the morphological grading, the blastocysts with excellent morphology displayed fewer polyploid nuclei in comparison to blastocysts with good (P=0.05) or poor morphology (P=0.01). There were however also prominent exceptions showing that a blastocyst with an excellent morphology can display a high degree of polyploidy. The results further demonstrate that the morphologically normal embryos contain a higher number of cells and develop more rapidly than the morphologically inferior embryos.
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Affiliation(s)
- Anne S Jakobsen
- Department of Large Animal Sciences, Veterinary Reproduction and Obstetrics, The Royal Veterinary and Agricultural University, Dyrlaegevej 68, 1870 Frederiksberg C, Denmark.
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29
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Bhak JS, Lee SL, Ock SA, Mohana Kumar B, Choe SY, Rho GJ. Developmental rate and ploidy of embryos produced by nuclear transfer with different activation treatments in cattle. Anim Reprod Sci 2005; 92:37-49. [PMID: 15979829 DOI: 10.1016/j.anireprosci.2005.04.016] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2004] [Revised: 02/21/2005] [Accepted: 04/22/2005] [Indexed: 11/21/2022]
Abstract
Bovine oocyte activation is one of the essential elements that determine the success of nuclear transfer and the subsequent development of cloned embryos. Three methods for oocyte activation, including 5 microM ionomycin (5 min, Group 1) alone, ionomycin+1.9 mM 6-dimethylaminopurine (DMAP, 3h, Group 2), and ionomycin+10 microg/ml cycloheximide (CHX, 3h, Group 3) were compared for the development of embryos produced by somatic nuclear transfer (SCNT) to parthenotes and IVF counterparts. At 19-h post-activation/insemination (hpa/hpi), 27.5% of oocytes in Group 2 cleaved and this rate was greater (P<0.05) than other groups (Group 1, 2.1%; Group 3, 3.0%). None of the oocytes in the IVF control group cleaved at 19-22 hpi. At 24 hpa, the rates of cleavage of oocytes in Group 2 (52.1%) were greater (P<0.05) than those in Groups 1 and 3 (7 and 38.3%, respectively). Only six oocytes (3.3%) in the IVF control group cleaved at 24 hpi. The overall cleavage rates of oocytes in Group 2 (85.5%) at 48 hpa were greater (P<0.05) than other treatments, but it did not show any difference when compared with the IVF control group (75.0%). The development rate to two-cell stage embryos of Group 2 was consistently greater at all observation points followed by Groups 3 and 1. Similar results were obtained in SCNT embryos, but the rates of cleavage at 48 hpi and blastocyst development in Group 2 (68.4 and 16.3%, respectively) did not differ from Group 3 (63.0 and 13.1%, respectively). The chromosomal composition in the parthenotes and SCNT embryos differed (P<0.05) among treatments. In Groups 1 and 3, greater percentages of haploid parthenotes (86 and 71%, respectively) were observed. In contrast, 84% of parthenotes in Group 2 had abnormal ploidy (44% polyploid and 40% mixoploid). In the case of SCNT embryos, Groups 1 and 3 had greater percentages of diploid chromosomal sets (77 and 70%, respectively), whereas 54% in Group 2 were polyploid or mixoploid. These results indicate that DMAP treatment after ionomycin greatly increases the developmental rates of parthenotes, but did not differ in blastocyst development compare with CHX treatment. However, DMAP treatment increased the time-dependent cleavage rate to two-cell stage embryos. Further, it greatly enhanced the incidence of chromosomal abnormalities in parthenotes and SCNT embryos. Hence, it is concluded that CHX combined with ionomycin is more desirable than DMAP for oocyte activation during nuclear transfer in cattle.
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Affiliation(s)
- Jong-Sik Bhak
- Department of Obstetrics and Theriogenology, College of Veterinary Medicine, Gyeongsang National University, 900 Gazwa, Chinju 660-701, South Korea
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30
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Li GP, Liu Y, White KL, Bunch TD. Cytogenetic analysis of diploidy in cloned bovine embryos using an improved air-dry karyotyping method. Theriogenology 2005; 63:2434-44. [PMID: 15910924 DOI: 10.1016/j.theriogenology.2004.09.056] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2004] [Accepted: 09/06/2004] [Indexed: 11/21/2022]
Abstract
Of the few published studies on the cytogenetic analyses of bovine nuclear transferred (NT) embryos, results differ between air-dry and fluorescent in situ hybridization (FISH) procedures. A modified air-dry procedure is reported in this study that provides more metaphase plates for analysis. Day 5 and Day 7 bovine NT embryos were cultured in colcemid-containing CR1aa for 10-12 or 16-18 h, then treated in hypotonic sodium citrate for 3-5 min. The standard procedure of 5h in colcemid and 15-20 min in hypotonic solution was the control. A much higher (P<0.01) percent of mitotic nuclei was observed in the experimental groups. The 33 and 41% mitotic nuclei were obtained from 10 to 12 h and 16 to 18 h-colcemid-treated Day 5 embryos, respectively, which was higher (P<0.001) than the control (15%). The mitotic nuclei in Day 7 NT embryos were 24% in 10-12 h- and 28% in 16-18 h-colcemid-treated groups, which also was higher (P<0.05) than the control (10%). The majority of analyzable embryos were diploid. Analyses of mixoploid embryos showed on average that 70% of the cells were diploid. Day 5 mixoploid embryos contained numerically higher polyploid cells than Day 7 embryos, although statistically there were no differences. We concluded that the modified air-dry method provided a larger source of mitotic nuclei for chromosome analyses of cloned bovine embryos.
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Affiliation(s)
- Guang-Peng Li
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, UT 84322, USA
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31
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Hanada H, Takeda K, Tagami T, Nirasawa K, Akagi S, Adachi N, Takahashi S, Izaike Y, Iwamoto M, Fuchimoto DI, Miyashita N, Kubo M, Onishi A, King WA. Chromosomal instability in the cattle clones derived by somatic cell nuclear-transfer. Mol Reprod Dev 2005; 71:36-44. [PMID: 15736125 DOI: 10.1002/mrd.20283] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Cytogenetic analysis was performed on peripheral lymphocytes collected from 20 cattle clones (19 showed no overt phenotypic abnormalities except for high birth weight while 1 exhibited left forelimb contracture), the donor cell cultures from which they were derived and lymphocytes from six insemination produced control cattle. All animals and cell cultures had a modal chromosome number of 60. The frequency of abnormal cells for donor cell cultures, clones, and controls was 6.68+/-0.30%, 5.30+/-5.49%, and 5.08+/-1.04%, respectively, and did not differ significantly among the groups. There were, however, two clones derived from different donor cell cultures with high incidences of 21.29% and 20.13%, of abnormal cells consisting of pseudodiploid (near-diploid), near-triploid and near-tetraploid, and tetraploid cells. Among these two clones, one had only a few endoreduplicated nuclei although further studies are necessary to precisely define the cytological origin and nature of the abnormal cells. The clones were evaluated at multiple time points for up to 20 months of age and the incidence of abnormal lymphocytes remained stable indicating that the chromosomally abnormal nuclei found in cloned animals was not a transient event. These results show that the majority of phenotypically normal clones have normal chromosomal make up but that instability of chromosome number can occur in clones that are phenotypically normal. Therefore, cytogenetical evaluation of peripheral lymphocytes and other tissues with follow up of the phenotypical consequences of these abnormalities is warranted even in phenotypically normal clones.
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Affiliation(s)
- Hirofumi Hanada
- Department of Animal Science, Tokyo University of Agriculture, Atugi, Japan.
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32
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Lonergan P, Pedersen HG, Rizos D, Greve T, Thomsen PD, Fair T, Evans A, Boland MP. Effect of the Post-Fertilization Culture Environment on the Incidence of Chromosome Aberrations in Bovine Blastocysts1. Biol Reprod 2004; 71:1096-100. [PMID: 15189826 DOI: 10.1095/biolreprod.104.030635] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
We have previously shown that the postfertilization embryo culture environment has a significant influence on the quality of the resulting bovine blastocyst measured in terms of its cryotolerance and relative abundance for several developmentally important gene transcripts. Using three different culture conditions known to produce blastocysts of differing quality, the objective of this study was to examine whether the postfertilization culture environment had an effect on the incidence of mixoploidy in bovine blastocysts. Presumptive zygotes, produced by in vitro maturation and fertilization, were cultured in vitro in synthetic oviduct fluid (SOF) medium in the absence or presence of fetal calf serum (FCS), or in vivo in the ewe oviduct. Blastocysts were recovered from the three systems at Day 7 and the incidence of mixoploidy was assessed using fluorescence in situ hybridization with chromosome 6- and chromosome 7-specific probes. A total of 10 025 nuclei were scored in 122 blastocysts. The frequency of normal, diploid, blastocysts was 8.8%, 21.4%, and 34.8% in embryos derived from culture in SOF+FCS, SOF, and the ewe oviduct, respectively, the remainder showing some degree of mixoploidy. The incidence of mixoploidy was apparently not related to the presence of serum; omission of serum from SOF resulted in a reduction in the incidence of mixoploidy (91.2% vs. 78.6%), although this difference was not significant. Culture in vivo, however, resulted in a significant (P < 0.01) reduction in the incidence of mixoploidy compared with culture in vitro in the presence of serum (65.2% vs. 91.2%, respectively). Among the mixoploid blastocysts, the majority contained less than 10% polyploid cells, irrespective of culture group (SOF, 69.7%; SOF+FCS, 64.5%; ewe oviduct, 60.0%). More than one type of polyploidy was frequently observed in mixoploid blastocysts. Overall, diploidy-triploidy was the most frequent abnormality, but diploid-tetraploid and diploid-triploid-tetraploid mosaics were also observed. A significantly higher proportion (P < 0.05) of blastocysts derived from SOF+FCS had more than one type of abnormality (80.6%, 25/ 31) compared with those derived from SOF (45.4%, 15/33) or in vivo culture (53.3%, 16/30). In conclusion, the postfertilization culture environment of the developing embryo can affect the incidence and severity of mixoploidy in the resulting blastocyst.
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Affiliation(s)
- Patrick Lonergan
- Department of Animal Science and Production, University College Dublin, Lyons Research Farm, Newcastle, County Dublin, Ireland.
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33
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Li GP, White KL, Aston KI, Meerdo LN, Bunch TD. Conditioned medium increases the polyploid cell composition of bovine somatic cell nuclear-transferred blastocysts. Reproduction 2004; 127:221-8. [PMID: 15056788 DOI: 10.1530/rep.1.00089] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The effects of bovine cumulus cell-conditioned medium on cloned bovine embryonic development and subsequent chromosome complement were examined using an air-dry procedure. Conditioned media were prepared using CR1aa supplemented with either fetal bovine serum (FBS) or bovine serum albumin (BSA). Nuclear-transferred embryos were reconstructed with nuclei from cumulus cells. Similar cleavage, morula, and blastocyst development was observed in conditioned media groups compared with the co-culture group. No differences (P > 0.05) were observed in the composition of blastocyst chromosomes after co-culture in different media, either with or without starvation of donor cells. The overall diploid blastocyst rate ranged from 75% to 84%. Chromosomal complement of blastocysts, however, was very different between conditioned medium and co-culture treatments. Overall incidence of chromosomal anomalies was 40% in conditioned medium, which was significantly higher (P < 0.001) than the co-culture group (20%). Moreover, a higher incidence (P < 0.05) of chromosomally abnormal blastocysts (41.5%) was observed after culture with FBS-containing conditioned medium than those cultured in BSA-containing conditioned medium (31.4%). No diploid improvement was observed after exchange of the culture system from conditioned medium to co-culture, or from co-culture to conditioned medium after the first 72 h of culture. The results of this study also indicated that the overall cell number was much lower (P < 0.01) in blastocysts with chromosomal abnormalities than those with a normal diploid state. We have concluded that medium conditioned with bovine cumulus cells increases the incidence of chromosomal anomalies in nuclear reconstructed embryos.
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Affiliation(s)
- G-P Li
- Department of Animal, Dairy and Veterinary Sciences, Utah State University, Logan, Utah 84322, USA
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34
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Shi W, Dirim F, Wolf E, Zakhartchenko V, Haaf T. Methylation Reprogramming and Chromosomal Aneuploidy in In Vivo Fertilized and Cloned Rabbit Preimplantation Embryos1. Biol Reprod 2004; 71:340-7. [PMID: 15028628 DOI: 10.1095/biolreprod.103.024554] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Active demethylation of the paternal genome but not of the maternal genome occurs in fertilized mouse, rat, pig, and bovine zygotes. To study whether this early demethylation wave is important for embryonic development, we have analyzed the global methylation patterns of both in vivo-fertilized and cloned rabbit embryos. Anti-5-methylcytosine immunofluorescence of in vivo-fertilized rabbit embryos revealed that the equally high methylation levels of the paternal and maternal genomes are largely maintained from the zygote up to the 16-cell stage. The lack of detectable methylation changes in rabbit preimplantation embryos suggests that genome-wide demethylation is not an obligatory requirement for epigenetic reprogramming. The methylation patterns of embryos derived from fibroblast and cumulus cell nuclear transfer were similar to those of in vivo-fertilized rabbit embryos. Fluorescence in situ hybridization with chromosome-specific BACs demonstrated significantly increased chromosomal aneuploidy rates in cumulus cell nuclear transfer rabbit embryos and embryos derived from nuclear transfer of rabbit fibroblasts into bovine oocytes compared with in vivo-fertilized rabbit embryos. The incidence of chromosomal abnormalities was correlated with subsequent developmental failure. We propose that postzygotic mitotic errors are one important explanation of why mammalian cloning often fails.
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Affiliation(s)
- Wei Shi
- Department of Molecular Animal Breeding and Biotechnology, University of Munich, 85764 Oberschleissheim, Germany
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35
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36
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Wells DN, Forsyth JT, McMillan V, Oback B. Review: The Health of Somatic Cell Cloned Cattle and Their Offspring. CLONING AND STEM CELLS 2004; 6:101-10. [PMID: 15268783 DOI: 10.1089/1536230041372300] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The cloning syndrome is a continuum with the consequences of abnormal reprogramming manifest throughout gestation, the neo-natal period, and into adulthood in the cloned generation, but it does not appear to be transmitted to subsequent offspring following sexual reproduction. Most in vivo studies on bovine somatic cell cloning have focused on development during pregnancy and the neo-natal period. In this paper, we report on the viability and health of cloned cattle in adulthood. From our studies at AgResearch, we find that between weaning and 4 years of age, the annual mortality rate in cattle cloned from somatic cells is at least 8%. Although the reasons for death are variable and some potentially preventable, the main mortality factor in this period is euthanasia due to musculoskeletal abnormalities. This includes animals with severely contracted flexor tendons and those displaying chronic lameness, particularly in milking cows. In contrast, no deaths beyond weaning have so far been encountered with the offspring of clones where the oldest animals are 3 years of age. In surviving cloned cattle, blood profiles and other indicators of general physiological function such as growth rate, reproduction, rearing of offspring, and milk production are all within the normal phenotypic ranges.
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Affiliation(s)
- D N Wells
- AgResearch Ltd., Ruakura Research Centre, Hamilton, New Zealand.
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37
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Bureau WS, Bordignon V, Léveillée C, Smith LC, King WA. Assessment of chromosomal abnormalities in bovine nuclear transfer embryos and in their donor cells. CLONING AND STEM CELLS 2004; 5:123-32. [PMID: 12930624 DOI: 10.1089/153623003322234722] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Chromosomal anomalies were assessed in nuclear transfer (NT) embryos (n = 148) at 1-4-cell stage (n = 88), and morula (n = 60), as well as in donor cells (n = 97) derived from two different cell lines. Two different cytogenetic approaches were used: conventional karyotyping and fluorescent in situ hybridization (FISH) with painting probes, specific for bovine X and Y chromosomes. The total rate of NT embryos with abnormal nuclei was 43%. These anomalies were mainly nuclear fragmentation (30%), hypoploidy/hypoploidy-mixoploidy (9%, n = 14) and hyperploidy/hyperploidy-mixoploidy (3%, n = 5). The incidence at which these anomalies occurred in NT embryos varied according to the donor cell culture and paralleled the frequency of anomalies in donor cells. A higher frequency of total anomalies was observed in NT embryos (55%) derived from the donor cell cultures with the highest incidence of anomalies (23%). An increase in the rate of total anomalies of the cell, after transfer to recipient cytoplasm, was also observed. These results suggest that proper screening of donor cells for chromosomal anomalies must be performed prior to NT procedure. They also suggest that the NT procedure itself might have a detrimental effect on some mechanism of chromosome segregation and distribution during cell division.
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Affiliation(s)
- W Slimane Bureau
- Department of Biomedical Sciences, Ontario Veterinary College, University of Guelph, Guelph, Canada.
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Kim YS, Lee SL, Ock SA, Balasubramanian S, Choe SY, Rho GJ. Development of cloned pig embryos by nuclear transfer following different activation treatments. Mol Reprod Dev 2004; 70:308-13. [PMID: 15625691 DOI: 10.1002/mrd.20211] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
This study compared the effects of activation treatments on the development and ploidy of nuclear transferred (NT) pig embryos. After in vitro maturation of oocytes collected from the slaughterhouse, oocytes were enucleated and reconstructed by transfer of donor cells and fusion with three DC pulses (1.4 kV/cm, 20 musec). Oocytes were pulsed thrice electrically with 1.4 kV/cm for 20 musec and NT eggs were divided into three treatment groups: Group 1 (no further treatment), Group 2 (10 mug/mL cycloheximide [CHX], 3 hr), and Group 3 (1.9 mM 6-dimethylaminopurine [DMAP], 3 hr). All the eggs were cultured in sets of 30 in 60 muL drops of NCSU-23 supplemented with 4 mg/mL fatty acid free BSA, and compared for the rates of development and ploidy. The rates of cleavage, development, and total cell number of parthenotes in Group 3 were significantly (P < 0.05) higher than those in Groups 1 and 2. Cleavage rates of NT embryos in Group 1 were significantly (P < 0.05) lower than those in Groups 2 and 3 (73% vs. 81% and 82%, respectively). Development into blastocyst stage and total cell number of NT embryos in Group 3 were significantly (P < 0.05) higher than those in Groups 1 and 2. Although the embryos in Group 3 had higher development, approximately 58% of NT embryos evaluated were abnormal ploidy (6% haploidy, 9% polyploidy, and 42% mixoploid). The results suggested that although DMAP enhanced development and higher cell number, due attention should be paid to abnormal ploidy in pig NT embryos.
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Affiliation(s)
- Yang-Sil Kim
- College of Veterinary Medicine, Gyeongsang National University, Chinju, Republic of Korea 660-701
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Greve T, Callesen H. Integrating new technologies with embryology and animal production. Reprod Fertil Dev 2004. [DOI: 10.1071/rd03084] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The present review describes a range of selected farm animal embryo technologies used in embryological research and applied in animal breeding and production. Some of the techniques are driven by the breeder’s wish to obtain animals with higher breeding values, whereas others are primarily driven by the curiosity of researchers. The interaction between basic research and practical application in these areas is still a characteristic feature for people who contribute to the International Embryo Transfer Society (IETS) and has been an advantage for both researchers and breeders. One example of such an interaction is that detailed structural analyses have described quality differences between embryos of various origins and, following embryo transfer, the pregnancy results have confirmed the correlation between morphology and viability. Another example is that polymerase chain reaction technology has allowed detection of Y-specific sequences in male embryos and has become a tool in animal production today. Data from domestic animal genome sequencing will provide a great deal of new information. A major challenge for the years to come will be using this information in a physiologically meaningful context and to continue the efforts to convert the laboratory experience into use in practise. Finally, it is important to obtain societal acceptance for a wider application of many of the technologies, such as in vitro embryo production and cloning.
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Boiani M, Eckardt S, Leu NA, Schöler HR, McLaughlin KJ. Pluripotency deficit in clones overcome by clone-clone aggregation: epigenetic complementation? EMBO J 2003; 22:5304-12. [PMID: 14517267 PMCID: PMC204490 DOI: 10.1093/emboj/cdg507] [Citation(s) in RCA: 135] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Abnormal gene expression patterns in somatic cell clones and their attrition in utero are commonly considered a consequence of errors in nuclear reprogramming. We observe that mouse clone blastocysts have less than half the normal cell number, and that higher cell number correlates with correct expression of Oct4, a gene essential for peri-implantation development and embryonic pluripotency. To increase the cell number, we aggregated genetically identical clones at the 4-cell stage. Clone-clone aggregates did not form more blastocysts, but the majority expressed Oct4 normally and had higher rates of fetal and postnatal development. Fertilized blastocysts with low cell numbers, induced by removal of two blastomeres at the 4-cell stage, did not exhibit abnormal Oct4 expression, indicating that improved gene expression and post-implantation development of clone-clone aggregates is not a consequence of increased cell number. Rather, we propose that complementation of non-cell-autonomous defects of genetically identical, but epigenetically different, embryos results in improved gene expression in clone-clone aggregates.
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Affiliation(s)
- Michele Boiani
- Germline Development Group, Center for Animal Transgenesis and Germ Cell Research, New Bolton Center, University of Pennsylvania, Kennett Square, PA 19348, USA
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