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Bhakta HH, Refai FH, Avella MA. The molecular mechanisms mediating mammalian fertilization. Development 2019; 146:146/15/dev176966. [PMID: 31375552 DOI: 10.1242/dev.176966] [Citation(s) in RCA: 37] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Fertilization is a key biological process in which the egg and sperm must recognize one another and fuse to form a zygote. Although the process is a continuum, mammalian fertilization has been studied as a sequence of steps: sperm bind and penetrate through the zona pellucida of the egg, adhere to the egg plasma membrane and finally fuse with the egg. Following fusion, effective blocks to polyspermy ensure monospermic fertilization. Here, we review how recent advances obtained using genetically modified mouse lines bring new insights into the molecular mechanisms regulating mammalian fertilization. We discuss models for these processes and we include studies showing that these mechanisms may be conserved across different mammalian species.
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Affiliation(s)
- Hanisha H Bhakta
- Department of Biological Science, College of Engineering and Natural Sciences, The University of Tulsa, Tulsa, OK 74104, USA
| | - Fares H Refai
- Department of Biological Science, College of Engineering and Natural Sciences, The University of Tulsa, Tulsa, OK 74104, USA
| | - Matteo A Avella
- Department of Biological Science, College of Engineering and Natural Sciences, The University of Tulsa, Tulsa, OK 74104, USA
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Ardestani G, West MC, Maresca TJ, Fissore RA, Stratton MM. FRET-based sensor for CaMKII activity (FRESCA): A useful tool for assessing CaMKII activity in response to Ca 2+ oscillations in live cells. J Biol Chem 2019; 294:11876-11891. [PMID: 31201271 DOI: 10.1074/jbc.ra119.009235] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Revised: 06/11/2019] [Indexed: 01/22/2023] Open
Abstract
Ca2+ oscillations and consequent Ca2+/calmodulin-dependent protein kinase II (CaMKII) activation are required for embryogenesis, as well as neuronal, immunological, and cardiac signaling. Fertilization directly results in Ca2+ oscillations, but the resultant pattern of CaMKII activity remains largely unclear. To address this gap, we first employed the one existing biosensor for CaMKII activation. This sensor, Camui, comprises CaMKIIα and therefore solely reports on the activation of this CaMKII variant. Additionally, to detect the activity of all endogenous CaMKII variants simultaneously, we constructed a substrate-based sensor for CaMKII activity, FRESCA (FRET-based sensor for CaMKII activity). To examine the differential responses of the Camui and FRESCA sensors, we used several approaches to stimulate Ca2+ release in mouse eggs, including addition of phospholipase Cζ cRNA, which mimics natural fertilization. We found that the Camui response is delayed or terminates earlier than the FRESCA response. FRESCA enables assessment of endogenous CaMKII activity in real-time by both fertilization and artificial reagents, such as Sr2+, which also leads to CaMKII activation. FRESCA's broad utility will be important for optimizing artificial CaMKII activation for clinical use to manage infertility. Moreover, FRESCA provides a new view on CaMKII activity, and its application in additional biological systems may reveal new signaling paradigms in eggs, as well as in neurons, cardiomyocytes, immune cells, and other CaMKII-expressing cells.
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Affiliation(s)
- Goli Ardestani
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts 01003.,Veterinary and Animal Sciences Graduate Program, University of Massachusetts, Amherst, Massachusetts 01003
| | - Megan C West
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003
| | - Thomas J Maresca
- Department of Biology, University of Massachusetts, Amherst, Massachusetts 01003
| | - Rafael A Fissore
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts 01003
| | - Margaret M Stratton
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Massachusetts 01003
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Fawzy M, Emad M, Mahran A, Sabry M, Fetih AN, Abdelghafar H, Rasheed S. Artificial oocyte activation with SrCl2 or calcimycin after ICSI improves clinical and embryological outcomes compared with ICSI alone: results of a randomized clinical trial. Hum Reprod 2019; 33:1636-1644. [PMID: 30099496 DOI: 10.1093/humrep/dey258] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 07/09/2018] [Indexed: 12/20/2022] Open
Abstract
STUDY QUESTION Are pregnancy and birth rates affected by artificial oocyte activation (AOA) with SrCl2 or calcimycin after ICSI for couples with male-factor infertility linked to abnormal sperm morphology or for couples with previous ICSI cycles of unexplained low fertilization or inadequate fertilization associated with impaired oocyte morphology? SUMMARY ANSWER AOA with either SrCl2 or calcimycin can improve the rates of clinical pregnancy, ongoing pregnancy and live birth compared with ICSI alone, and the two agents have diverse effects for different subgroups of patients. WHAT IS KNOWN ALREADY ICSI is a successful treatment for infertility, but not in all individuals. AOA has potential to overcome inadequate fertilization in ICSI. Calcimycin and SrCl2 are candidate agents for AOA, but their effectiveness remains to be compared. STUDY DESIGN, SIZE, DURATION This study was a randomized, open-label, three-arm, parallel-group, double-centre, superiority trial conducted between April 2015 and January 2016. The study evaluated the effects of AOA with calcimycin or SrCl2 for clinical pregnancy rates after ICSI and included 343 couples divided into three groups. PARTICIPANTS/MATERIALS, SETTING, METHODS Couples were included if they had two previous ICSI cycles of no or low fertilization (0-30%) with unknown causes or impaired oocyte morphology. Male-factor infertility cycles (frozen-thawed sperm, surgically retrieved sperm or ejaculates contained <10 millions spermatozoa/ml) undergoing their first ICSI attempt were also included if they had 100% abnormal sperm morphology (including globozoospermia and tapered-head). Couples were randomized to undergo ICSI with SrCl2 AOA, ICSI with calcimycin AOA or ICSI alone, with clinical pregnancy as the primary endpoint. Effect sizes were summarized as absolute rate differences (ARDs) and odds ratios (ORs), with precision evaluated by 95% CIs. MAIN RESULTS AND THE ROLE OF CHANCE Both SrCl2 and calcimycin AOA improved clinical pregnancy rates compared to ICSI alone (49, 42 and 27%; ARD 22, 95% CI: 9-33; P = 0.0007 and ARD 16, 95% CI: 3-27; P = 0.014). SrCl2 and calcimycin AOA were also superior to ICSI alone on the rates of ongoing pregnancy (42, 36 and 23%; P = 0.0019 and P = 0.023) and live birth (40, 33 and 18%; P = 0.0002 and P = 0.012). Among couples with previous ICSI cycles of low fertilization, AOA with SrCl2 (but not with calcimycin) was superior to ICSI alone for rates of clinical pregnancy (ARD 35 percentage points (pp), P = 0.0007), ongoing pregnancy (ARD 27 pp, P = 0.009) and live birth (ARD 37 pp, P = 0.002). Among couples affected by male-factor infertility, AOA with calcimycin (but not with SrCl2) was superior to ICSI alone for rates of clinical pregnancy (ARD 22 pp, P = 0.006), ongoing pregnancy (ARD 19 pp, P = 0.013) and live birth (ARD 17 pp, P = 0.02). LIMITATIONS, REASONS FOR CAUTION This study was an open-label trial, and this design might have introduced bias, although randomization methods were used. The study did not include a longitudinal follow-up, so further evidence is required to demonstrate the safety of AOA. WIDER IMPLICATIONS OF THE FINDINGS The decision to use SrCl2 or calcimycin for AOA after ICSI may depend on whether the activation failure originates in the oocyte or the sperm. STUDY FUNDING/COMPETING INTEREST(S) The study received no funding and the authors have no conflicts of interest to declare. TRIAL REGISTRATION NUMBER NCT02424214. TRIAL REGISTRATION DATE 22 April 2015. DATE OF FIRST PATIENT’S ENROLMENT 27 April 2015.
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Affiliation(s)
| | - Mai Emad
- IbnSina IVF Centre, IbnSina Hospital, Sohag, Egypt
| | - Ali Mahran
- Department of Dermatology, Venereology and Andrology, Faculty of Medicine, Assiut University, AG, Egypt
| | - Mohamed Sabry
- Department of Obstetrics and Gynecology, Sohag University, Sohag, Egypt
| | - Ahmed N Fetih
- Department of Obstetrics and Gynecology, Faculty of Medicine, Assiut University, AG, Egypt
| | - Hazem Abdelghafar
- Department of Obstetrics and Gynecology, Sohag University, Sohag, Egypt
| | - Salah Rasheed
- Department of Obstetrics and Gynecology, Sohag University, Sohag, Egypt
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Schneider I, Ellenberg J. Mysteries in embryonic development: How can errors arise so frequently at the beginning of mammalian life? PLoS Biol 2019; 17:e3000173. [PMID: 30840627 PMCID: PMC6422315 DOI: 10.1371/journal.pbio.3000173] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Revised: 03/18/2019] [Indexed: 12/21/2022] Open
Abstract
Chromosome segregation errors occur frequently during female meiosis but also in the first mitoses of mammalian preimplantation development. Such errors can lead to aneuploidy, spontaneous abortions, and birth defects. Some of the mechanisms underlying these errors in meiosis have been deciphered but which mechanisms could cause chromosome missegregation in the first embryonic cleavage divisions is mostly a “mystery”. In this article, we describe the starting conditions and challenges of these preimplantation divisions, which might impair faithful chromosome segregation. We also highlight the pending research to provide detailed insight into the mechanisms and regulation of preimplantation mitoses. Starting a new life is a challenging business. This Essay explores the changes at the oocyte-to-embryo transition to highlight the circumstances under which the very first and decisive — but ‘mysteriously’ error-prone — mitotic divisions occur.
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Affiliation(s)
- Isabell Schneider
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- Candidate for joint PhD degree between EMBL and Heidelberg University, Faculty of Biosciences, Heidelberg, Germany
| | - Jan Ellenberg
- Cell Biology and Biophysics Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- * E-mail:
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Zhao S, Chen T, Yu M, Bian Y, Cao Y, Ning Y, Su S, Zhang J, Zhao S. Novel WEE2 gene variants identified in patients with fertilization failure and female infertility. Fertil Steril 2019; 111:519-526. [DOI: 10.1016/j.fertnstert.2018.11.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 10/30/2018] [Accepted: 11/14/2018] [Indexed: 12/12/2022]
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Dua D, Nagoorvali D, Chauhan MS, Palta P, Mathur P, Singh MK. Calcium ionophore enhanced developmental competence and apoptotic dynamics of goat parthenogenetic embryos produced in vitro. In Vitro Cell Dev Biol Anim 2019; 55:159-168. [PMID: 30737632 DOI: 10.1007/s11626-019-00322-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 01/16/2019] [Indexed: 12/21/2022]
Abstract
Parthenogenetically developed embryos are efficient sources of in vitro embryo production, having less ethical issue and being useful for investigating culture conditions/treatments, early developmental, genomic studies, and homonymous source of stem cells. Keeping its advantages in mind, we aimed to study the effects of different activating agents on embryo production and its quality and gene expression. In the present study, 1348 immature oocytes recovered were parthenogenetically developed to embryos. Usable-quality immature oocytes were collected by puncturing the surface follicles and matured in in vitro maturation (IVM) medium for 27 h in a humidified 5% CO2 incubator at 38.5°C. The matured oocytes were parthenogenetically activated by exposure to 5 μM calcium ionophore for 5 min or 7% ethanol for 7 min sequentially followed by 4 h incubation in 2 mM 6-DMAP and then in vitro cultured (IVC) in RVCL/G-2 medium for 8 days. Matured oocytes were activated by calcium ionophore, the cleavage rate observed was 76.67 ± 3.47%, and further they developed into 4-cell, 8-16-cell, morula, blastocyst, and hatched blastocyst with 85.30 ± 1.57%, 70.60 ± 2.00%, 45.05 ± 2.66%, 22.89 ± 2.40%, and 5.70 ± 1.97%, respectively. Whereas ethanol-activated oocytes showed cleavage rate of 87.60 ± 1.70% and further culture developed into 4-cell, 8-16 cell, morula, blastocyst, and hatched blastocyst with 86.14 ± 1.03%, 71.56 ± 2.21%, 40.90 ± 2.45%, 19.02 ± 1.26%, and 2.22 ± 0.38%, respectively. Blastocyst developed from calcium ionophore-activated oocytes showed significantly (P < 0.05) higher total cell number (282.25 ± 27.02 vs 206.00 ± 40.46) and a lower apoptotic index (2.42 ± 0.46 vs 4.07 ± 1.44) than blastocyst developed from ethanol-activated oocytes. The relative expression of anti-apoptotic genes (BCL2, BCL2A1, MCL) at different stages of embryos produced by either calcium ionophore or ethanol activation was found to be increased in earlier stages and decreased in later stages of embryonic development. Similarly, when these embryos were subjected to pro-apoptotic genes (BAX, BAD, BAK), expression was found to be slightly higher in blastocysts than other stages. This study shows that calcium ionophore-activated blastocysts were developmentally more competent than the ethanol-activated blastocysts.
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Affiliation(s)
- Diksha Dua
- Animal Biotechnology Centre, ICAR-National Dairy Research Institute, Karnal, 132001, India
| | - D Nagoorvali
- Animal Biotechnology Centre, ICAR-National Dairy Research Institute, Karnal, 132001, India
| | - M S Chauhan
- ICAR-Central Institute for Research on Goats, Makhdum, Mathura, 281122, India
| | - P Palta
- Animal Biotechnology Centre, ICAR-National Dairy Research Institute, Karnal, 132001, India
| | - P Mathur
- Amity Institute of Biotechnology, Amity University, Noida, 201303, India
| | - M K Singh
- Animal Biotechnology Centre, ICAR-National Dairy Research Institute, Karnal, 132001, India.
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Uh K, Ryu J, Zhang L, Errington J, Machaty Z, Lee K. Development of novel oocyte activation approaches using Zn2+ chelators in pigs. Theriogenology 2019; 125:259-267. [DOI: 10.1016/j.theriogenology.2018.11.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Revised: 10/31/2018] [Accepted: 11/14/2018] [Indexed: 10/27/2022]
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Ferrer-Buitrago M, Dhaenens L, Lu Y, Bonte D, Vanden Meerschaut F, De Sutter P, Leybaert L, Heindryckx B. Human oocyte calcium analysis predicts the response to assisted oocyte activation in patients experiencing fertilization failure after ICSI. Hum Reprod 2019; 33:416-425. [PMID: 29329390 DOI: 10.1093/humrep/dex376] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/12/2017] [Indexed: 11/15/2022] Open
Abstract
STUDY QUESTION Can human oocyte calcium analysis predict fertilization success after assisted oocyte activation (AOA) in patients experiencing fertilization failure after ICSI? SUMMARY ANSWER ICSI-AOA restores the fertilization rate only in patients displaying abnormal Ca2+ oscillations during human oocyte activation. WHAT IS KNOWN ALREADY Patients capable of activating mouse oocytes and who showed abnormal Ca2+ profiles after mouse oocyte Ca2+ analysis (M-OCA), have variable responses to ICSI-AOA. It remains unsettled whether human oocyte Ca2+ analysis (H-OCA) would yield an improved accuracy to predict fertilization success after ICSI-AOA. STUDY DESIGN, SIZE, DURATION Sperm activation potential was first evaluated by MOAT. Subsequently, Ca2+ oscillatory patterns were determined with sperm from patients showing moderate to normal activation potential based on the capacity of human sperm to generate Ca2+ responses upon microinjection in mouse and human oocytes. Altogether, this study includes a total of 255 mouse and 122 human oocytes. M-OCA was performed with 16 different sperm samples before undergoing ICSI-AOA treatment. H-OCA was performed for 11 patients who finally underwent ICSI-AOA treatment. The diagnostic accuracy to predict fertilization success was calculated based on the response to ICSI-AOA. PARTICIPANTS/MATERIALS, SETTING, METHODS Patients experiencing low or total failed fertilization after conventional ICSI were included in the study. All participants showed moderate to high rates of activation after MOAT. Metaphase II (MII) oocytes from B6D2F1 mice were used for M-OCA. Control fertile sperm samples were used to obtain a reference Ca2+ oscillation profile elicited in human oocytes. Donated human oocytes, non-suitable for IVF treatments, were collected and vitrified at MII stage for further analysis by H-OCA. MAIN RESULTS AND THE ROLE OF CHANCE M-OCA and H-OCA predicted the response to ICSI-AOA in 8 out of 11 (73%) patients. Compared to M-OCA, H-OCA detected the presence of sperm activation deficiencies with greater sensitivity (75 vs 100%, respectively). ICSI-AOA never showed benefit to overcome fertilization failure in patients showing normal capacity to generate Ca2+ oscillations in H-OCA and was likely to be beneficial in cases displaying abnormal H-OCA Ca2+ oscillations patterns. LIMITATIONS, REASONS FOR CAUTION The scarce availability of human oocytes donated for research purposes is a limiting factor to perform H-OCA. Ca2+ imaging requires specific equipment to monitor fluorescence changes over time. WIDER IMPLICATIONS OF THE FINDINGS H-OCA is a sensitive test to diagnose gamete-linked fertilization failure. H-OCA allows treatment counseling for couples experiencing ICSI failures to either undergo ICSI-AOA or to participate in gamete donation programs. The present data provide an important template of the Ca2+ signature observed during human fertilization in cases with normal, low and failed fertilization after conventional ICSI. STUDY FUNDING/COMPETING INTEREST(S) This work was supported by the Flemish fund for scientific research (FWO-Vlaanderen, G060615N). The authors have no conflict of interest to declare.
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Affiliation(s)
- M Ferrer-Buitrago
- Ghent-Fertility and Stem Cell Team (G-FaST), Department for Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - L Dhaenens
- Ghent-Fertility and Stem Cell Team (G-FaST), Department for Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - Y Lu
- Ghent-Fertility and Stem Cell Team (G-FaST), Department for Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - D Bonte
- Ghent-Fertility and Stem Cell Team (G-FaST), Department for Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - F Vanden Meerschaut
- Ghent-Fertility and Stem Cell Team (G-FaST), Department for Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - P De Sutter
- Ghent-Fertility and Stem Cell Team (G-FaST), Department for Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - L Leybaert
- Physiology Group, Department of Basic Medical Sciences, Faculty of Medicine and Health Sciences, Ghent University, De Pintelaan 185, 9000 Ghent, Belgium
| | - B Heindryckx
- Ghent-Fertility and Stem Cell Team (G-FaST), Department for Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
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Fontana JM, Khodus GR, Unnersjö-Jess D, Blom H, Aperia A, Brismar H. Spontaneous calcium activity in metanephric mesenchymal cells regulates branching morphogenesis in the embryonic kidney. FASEB J 2018; 33:4089-4096. [PMID: 30496703 PMCID: PMC6404591 DOI: 10.1096/fj.201802054r] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The central role of calcium signaling during development of early vertebrates is well documented, but little is known about its role in mammalian embryogenesis. We have used immunofluorescence and time-lapse calcium imaging of cultured explanted embryonic rat kidneys to study the role of calcium signaling for branching morphogenesis. In mesenchymal cells, we recorded spontaneous calcium activity that was characterized by irregular calcium transients. The calcium signals were dependent on release of calcium from intracellular stores in the endoplasmic reticulum. Down-regulation of the calcium activity, both by blocking the sarco-endoplasmic reticulum Ca2+-ATPase and by chelating cytosolic calcium, resulted in retardation of branching morphogenesis and a reduced formation of primitive nephrons but had no effect on cell proliferation. We propose that spontaneous calcium activity contributes with a stochastic factor to the self-organizing process that controls branching morphogenesis, a major determinant of the ultimate number of nephrons in the kidney.-Fontana, J. M., Khodus, G. R., Unnersjö-Jess, D., Blom, H., Aperia, A., Brismar, H. Spontaneous calcium activity in metanephric mesenchymal cells regulates branching morphogenesis in the embryonic kidney.
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Affiliation(s)
- Jacopo M Fontana
- Department of Applied Physics, Science for Life Laboratory, Kungliga Tekniska Högskolan (KTH) Royal Institute of Technology, Solna, Sweden
| | - Georgiy R Khodus
- Department of Applied Physics, Science for Life Laboratory, Kungliga Tekniska Högskolan (KTH) Royal Institute of Technology, Solna, Sweden
| | - David Unnersjö-Jess
- Department of Applied Physics, Science for Life Laboratory, Kungliga Tekniska Högskolan (KTH) Royal Institute of Technology, Solna, Sweden
| | - Hans Blom
- Department of Applied Physics, Science for Life Laboratory, Kungliga Tekniska Högskolan (KTH) Royal Institute of Technology, Solna, Sweden
| | - Anita Aperia
- Department of Women's and Children's Health, Science for Life Laboratory, Karolinska Institutet, Solna, Sweden
| | - Hjalmar Brismar
- Department of Applied Physics, Science for Life Laboratory, Kungliga Tekniska Högskolan (KTH) Royal Institute of Technology, Solna, Sweden.,Department of Women's and Children's Health, Science for Life Laboratory, Karolinska Institutet, Solna, Sweden
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TRPM7 and Ca V3.2 channels mediate Ca 2+ influx required for egg activation at fertilization. Proc Natl Acad Sci U S A 2018; 115:E10370-E10378. [PMID: 30322909 DOI: 10.1073/pnas.1810422115] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The success of mammalian development following fertilization depends on a series of transient increases in egg cytoplasmic Ca2+, referred to as Ca2+ oscillations. Maintenance of these oscillations requires Ca2+ influx across the plasma membrane, which is mediated in part by T-type, CaV3.2 channels. Here we show using genetic mouse models that TRPM7 channels are required to support this Ca2+ influx. Eggs lacking both TRPM7 and CaV3.2 stop oscillating prematurely, indicating that together they are responsible for the majority of Ca2+ influx immediately following fertilization. Fertilized eggs lacking both channels also frequently display delayed resumption of Ca2+ oscillations, which appears to require sperm-egg fusion. TRPM7 and CaV3.2 channels almost completely account for Ca2+ influx observed following store depletion, a process previously attributed to canonical store-operated Ca2+ entry mediated by STIM/ORAI interactions. TRPM7 serves as a membrane sensor of extracellular Mg2+ and Ca2+ concentrations and mediates the effects of these ions on Ca2+ oscillation frequency. When bred to wild-type males, female mice carrying eggs lacking TRPM7 and CaV3.2 are subfertile, and their offspring have increased variance in postnatal weight. These in vivo findings confirm previous observations linking in vitro experimental alterations in Ca2+ oscillatory patterns with developmental potential and offspring growth. The identification of TRPM7 and CaV3.2 as key mediators of Ca2+ influx following fertilization provides a mechanistic basis for the rational design of culture media that optimize developmental potential in research animals, domestic animals, and humans.
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Wang F, Yuan RY, Li L, Meng TG, Fan LH, Jing Y, Zhang RR, Li YY, Liang QX, Dong F, Hou Y, Schatten H, Sun QY, Ou XH. Mitochondrial regulation of [Ca 2+]i oscillations during cell cycle resumption of the second meiosis of oocyte. Cell Cycle 2018; 17:1471-1486. [PMID: 29965788 DOI: 10.1080/15384101.2018.1489179] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Oocyte is arrested at metaphase of the second meiosis until fertilization switching on [Ca2+]i oscillations. Oocyte activation inefficiency is the most challenging problem for failed fertilization and embryonic development. Mitochondrial function and intracellular [Ca2+]i oscillations are two critical factors for the oocyte's developmental potential. We aimed to understand the possible correlation between mitochondrial function and [Ca2+]i oscillations in oocytes. To this end, mitochondrial uncoupler CCCP which damages mitochondrial function and two small molecule mitochondrial agonists, L-carnitine (LC) and BGP-15, were used to examine the regulation of [Ca2+]i by mitochondrial functions. With increasing CCCP concentrations, [Ca2+]i oscillations were gradually diminished and high concentrations of CCCP led to oocyte death. LC enhanced mitochondrial membrane potential and [Ca2+]i oscillations and even improved the damage induced by CCCP, however, BGP-15 had no beneficial effect on oocyte activation. We have found that mitochondrial function plays a vital role in the generation of [Ca2+]i oscillations in oocytes, and thus mitochondria may interact with the ER to generate [Ca2+]i oscillations during oocyte activation. Improvement of mitochondrial functions with small molecules can be expected to improve oocyte activation and embryonic development in infertile patients without invasive micromanipulation.
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Affiliation(s)
- Feng Wang
- a Fertility Preservation Lab , Reproductive Medicine Center, Guangdong Second Provincial General Hospital , Guangzhou , China.,b State Key Laboratory of Stem Cell and Reproductive Biology , Institute of Zoology, Chinese Academy of Sciences , Beijing , China
| | - Rui-Ying Yuan
- a Fertility Preservation Lab , Reproductive Medicine Center, Guangdong Second Provincial General Hospital , Guangzhou , China
| | - Li Li
- b State Key Laboratory of Stem Cell and Reproductive Biology , Institute of Zoology, Chinese Academy of Sciences , Beijing , China
| | - Tie-Gang Meng
- b State Key Laboratory of Stem Cell and Reproductive Biology , Institute of Zoology, Chinese Academy of Sciences , Beijing , China
| | - Li-Hua Fan
- b State Key Laboratory of Stem Cell and Reproductive Biology , Institute of Zoology, Chinese Academy of Sciences , Beijing , China
| | - Ying Jing
- b State Key Laboratory of Stem Cell and Reproductive Biology , Institute of Zoology, Chinese Academy of Sciences , Beijing , China
| | - Ren-Ren Zhang
- b State Key Laboratory of Stem Cell and Reproductive Biology , Institute of Zoology, Chinese Academy of Sciences , Beijing , China
| | - Yuna-Yuan Li
- b State Key Laboratory of Stem Cell and Reproductive Biology , Institute of Zoology, Chinese Academy of Sciences , Beijing , China
| | - Qiu-Xia Liang
- b State Key Laboratory of Stem Cell and Reproductive Biology , Institute of Zoology, Chinese Academy of Sciences , Beijing , China
| | - Feng Dong
- b State Key Laboratory of Stem Cell and Reproductive Biology , Institute of Zoology, Chinese Academy of Sciences , Beijing , China
| | - Yi Hou
- b State Key Laboratory of Stem Cell and Reproductive Biology , Institute of Zoology, Chinese Academy of Sciences , Beijing , China
| | - Heide Schatten
- c Department of Veterinary Pathobiology , University of Missouri , Columbia , MO , USA
| | - Qing-Yuan Sun
- b State Key Laboratory of Stem Cell and Reproductive Biology , Institute of Zoology, Chinese Academy of Sciences , Beijing , China.,d University of Chinese Academy of Sciences , Beijing , China
| | - Xiang-Hong Ou
- a Fertility Preservation Lab , Reproductive Medicine Center, Guangdong Second Provincial General Hospital , Guangzhou , China
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Carvacho I, Piesche M, Maier TJ, Machaca K. Ion Channel Function During Oocyte Maturation and Fertilization. Front Cell Dev Biol 2018; 6:63. [PMID: 29998105 PMCID: PMC6028574 DOI: 10.3389/fcell.2018.00063] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 06/04/2018] [Indexed: 12/20/2022] Open
Abstract
The proper maturation of both male and female gametes is essential for supporting fertilization and the early embryonic divisions. In the ovary, immature fully-grown oocytes that are arrested in prophase I of meiosis I are not able to support fertilization. Acquiring fertilization competence requires resumption of meiosis which encompasses the remodeling of multiple signaling pathways and the reorganization of cellular organelles. Collectively, this differentiation endows the egg with the ability to activate at fertilization and to promote the egg-to-embryo transition. Oocyte maturation is associated with changes in the electrical properties of the plasma membrane and alterations in the function and distribution of ion channels. Therefore, variations on the pattern of expression, distribution, and function of ion channels and transporters during oocyte maturation are fundamental to reproductive success. Ion channels and transporters are important in regulating membrane potential, but also in the case of calcium (Ca2+), they play a critical role in modulating intracellular signaling pathways. In the context of fertilization, Ca2+ has been shown to be the universal activator of development at fertilization, playing a central role in early events associated with egg activation and the egg-to-embryo transition. These early events include the block of polyspermy, the completion of meiosis and the transition to the embryonic mitotic divisions. In this review, we discuss the role of ion channels during oocyte maturation, fertilization and early embryonic development. We will describe how ion channel studies in Xenopus oocytes, an extensively studied model of oocyte maturation, translate into a greater understanding of the role of ion channels in mammalian oocyte physiology.
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Affiliation(s)
- Ingrid Carvacho
- Department of Biology and Chemistry, Faculty of Basic Sciences, Universidad Católica del Maule, Talca, Chile
| | - Matthias Piesche
- Biomedical Research Laboratories, Medicine Faculty, Universidad Católica del Maule, Talca, Chile
| | - Thorsten J. Maier
- Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, Goethe-University Hospital, Frankfurt, Germany
| | - Khaled Machaca
- Department of Physiology and Biophysics, Weill Cornell-Medicine-Qatar, Education City, Qatar Foundation, Doha, Qatar
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63
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Zhong L, Mu H, Wen B, Zhang W, Wei Q, Gao G, Han J, Cao S. Long non-coding RNAs involved in the regulatory network during porcine pre-implantation embryonic development and iPSC induction. Sci Rep 2018; 8:6649. [PMID: 29703926 PMCID: PMC5923264 DOI: 10.1038/s41598-018-24863-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 04/05/2018] [Indexed: 12/16/2022] Open
Abstract
Long non-coding RNAs (lncRNA) play a key role in the orchestration of transcriptional regulation during development and many other cellular processes. The importance of the regulatory co-expression network was highlighted in the identification of the mechanism of these processes in humans and mice. However, elucidation of the properties of porcine lncRNAs involved in the regulatory network during pre-implantation embryonic development and fibroblast reprogramming to induced pluripotent stem cell (iPSC) has been limited to date. Using a weighted gene co-expression network analysis, we constructed the regulatory network and determined that the novel lncRNAs were functionally involved in key events of embryonic development during the pre-implantation period; moreover, reprogramming could be delineated by a small number of potentially functional modules of co-expressed genes. These findings indicate that lncRNAs may be involved in the transcriptional regulation of zygotic genome activation, first lineage segregation and somatic reprogramming to pluripotency. Furthermore, we performed a conservation and synteny analysis with the significant lncRNAs involved in these vital events and validated the results via experimental assays. In summary, the current findings provide a valuable resource to dissect the protein coding gene and lncRNA regulatory networks that underlie the progressive development of embryos and somatic reprogramming.
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Affiliation(s)
- Liang Zhong
- The Animal Science and Technology College, Beijing University of Agriculture, Beijing, China.,State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Haiyuan Mu
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Bingqiang Wen
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Wei Zhang
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Qingqing Wei
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Ge Gao
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Center for Bioinformatics, Peking University, Beijing, China
| | - Jianyong Han
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China.
| | - Suying Cao
- The Animal Science and Technology College, Beijing University of Agriculture, Beijing, China. .,Beijing Key Laboratory of Traditional Chinese Veterinary Medicine, Beijing University of Agriculture, Beijing, China.
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64
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Sang Q, Li B, Kuang Y, Wang X, Zhang Z, Chen B, Wu L, Lyu Q, Fu Y, Yan Z, Mao X, Xu Y, Mu J, Li Q, Jin L, He L, Wang L. Homozygous Mutations in WEE2 Cause Fertilization Failure and Female Infertility. Am J Hum Genet 2018; 102:649-657. [PMID: 29606300 DOI: 10.1016/j.ajhg.2018.02.015] [Citation(s) in RCA: 111] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Accepted: 02/20/2018] [Indexed: 11/29/2022] Open
Abstract
Fertilization is a fundamental process of development and is a prerequisite for successful human reproduction. In mice, although several receptor proteins have been shown to play important roles in the process of fertilization, only three genes have been shown to cause fertilization failure and infertility when deleted in vivo. In clinical practice, some infertility case subjects suffer from recurrent failure of in vitro fertilization and intracytoplasmic sperm injection attempts due to fertilization failure, but the genetic basis of fertilization failure in humans remains largely unknown. Wee2 is a key oocyte-specific kinase involved in the control of meiotic arrest in mice, but WEE2 has not been associated with any diseases in humans. In this study, we identified homozygous mutations in WEE2 that are responsible for fertilization failure in humans. All four independent affected individuals had homozygous loss-of-function missense mutations or homozygous frameshift protein-truncating mutations, and the phenotype of fertilization failure was shown to follow a Mendelian recessive inheritance pattern. All four mutations significantly decreased the amount of WEE2 protein in vitro and in affected individuals' oocytes in vivo, and they all led to abnormal serine phosphorylation of WEE2 and reduced tyrosine 15 phosphorylation of Cdc2 in vitro. In addition, injection of WEE2 cRNA into affected individuals' oocytes rescued the fertilization failure phenotype and led to the formation of blastocysts in vitro. This work presents a novel gene responsible for human fertilization failure and has implications for future therapeutic treatments for infertility cases.
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Affiliation(s)
- Qing Sang
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Institutes of Biomedical Sciences, Zhongshan Hospital, Fudan University, Shanghai 200032, China; GMU-GIBH Joint School of Life Sciences, Guangzhou Medical University, Guangzhou 511436, China.
| | - Bin Li
- Reproductive Medicine Center, Shanghai Ninth Hospital, Shanghai Jiao Tong University, Shanghai 200011, China
| | - Yanping Kuang
- Reproductive Medicine Center, Shanghai Ninth Hospital, Shanghai Jiao Tong University, Shanghai 200011, China
| | - Xueqian Wang
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Institutes of Biomedical Sciences, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Zhihua Zhang
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Institutes of Biomedical Sciences, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Biaobang Chen
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Institutes of Biomedical Sciences, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Ling Wu
- Reproductive Medicine Center, Shanghai Ninth Hospital, Shanghai Jiao Tong University, Shanghai 200011, China
| | - Qifeng Lyu
- Reproductive Medicine Center, Shanghai Ninth Hospital, Shanghai Jiao Tong University, Shanghai 200011, China
| | - Yonglun Fu
- Reproductive Medicine Center, Shanghai Ninth Hospital, Shanghai Jiao Tong University, Shanghai 200011, China
| | - Zheng Yan
- Reproductive Medicine Center, Shanghai Ninth Hospital, Shanghai Jiao Tong University, Shanghai 200011, China
| | - Xiaoyan Mao
- Reproductive Medicine Center, Shanghai Ninth Hospital, Shanghai Jiao Tong University, Shanghai 200011, China
| | - Yao Xu
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Institutes of Biomedical Sciences, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Jian Mu
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Institutes of Biomedical Sciences, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Qiaoli Li
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Institutes of Biomedical Sciences, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Li Jin
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Institutes of Biomedical Sciences, Zhongshan Hospital, Fudan University, Shanghai 200032, China
| | - Lin He
- Bio-X Center, Key Laboratory for the Genetics of Developmental and Neuropsychiatric Disorders, Ministry of Education, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Lei Wang
- State Key Laboratory of Genetic Engineering and School of Life Sciences, Institutes of Biomedical Sciences, Zhongshan Hospital, Fudan University, Shanghai 200032, China; GMU-GIBH Joint School of Life Sciences, Guangzhou Medical University, Guangzhou 511436, China.
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65
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Zhang L, Chao CH, Jaeger LA, Papp AB, Machaty Z. Calcium oscillations in fertilized pig oocytes are associated with repetitive interactions between STIM1 and ORAI1. Biol Reprod 2018; 98:510-519. [PMID: 29365044 PMCID: PMC5905661 DOI: 10.1093/biolre/ioy016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 12/01/2017] [Accepted: 01/19/2018] [Indexed: 11/15/2022] Open
Abstract
The Ca2+ entry mechanism that sustains the Ca2+ oscillations in fertilized pig oocytes was investigated. Stromal interaction molecule 1 (STIM1) and ORAI1 proteins tagged with various fluorophores were expressed in the oocytes. In some cells, the Ca2+ stores were depleted using cyclopiazonic acid (CPA); others were inseminated. Changes in the oocytes' cytosolic free Ca2+ concentration were monitored, while interaction between the expressed fusion proteins was investigated using fluorescence resonance energy transfer (FRET). Store depletion led to an increase of the FRET signal in oocytes co-expressing mVenus-STIM1 and mTurquoise2-ORAI1, indicating that Ca2+ release was followed by an interaction between these proteins. A similar FRET increase in response to CPA was also detected in oocytes co-expressing mVenus-STIM1 and mTurquoise2-STIM1, which is consistent with STIM1 forming punctae after store depletion. ML-9, an inhibitor that can interfere with STIM1 puncta formation, blocked store-operated Ca2+ entry (SOCE) induced by Ca2+ add-back after a CPA treatment; it also disrupted the Ca2+ oscillations in fertilized oocytes. In addition, oocytes overexpressing mVenus-STIM1 showed high-frequency Ca2+ oscillations when fertilized, arguing for an active role of the protein. High-frequency Ca2+ oscillations were also detected in fertilized oocytes co-expressing mVenus-STIM1 and mTurquoise2-ORAI1, and both of these high-frequency Ca2+ oscillations could be stopped by inhibitors of SOCE. Importantly, in oocytes co-expressing mVenus-STIM1 and mTurquoise2-ORAI1, we were also able to detect cyclic increases of the FRET signal indicating repetitive interactions between STIM1 and ORAI1. The results confirm the notion that in pig oocytes, SOCE is involved in the maintenance of the repetitive Ca2+ transients at fertilization.
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Affiliation(s)
- Lu Zhang
- Department of Animal Sciences, Purdue University, West Lafayette, Indiana, USA
| | | | - Laurie A Jaeger
- Department of Basic Medical Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Agnes Bali Papp
- Department of Animal Sciences, Széchenyi István University, Győr, Hungary
| | - Zoltan Machaty
- Department of Animal Sciences, Purdue University, West Lafayette, Indiana, USA
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66
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Dehydroepiandrosterone (DHEA) and Its Sulfate (DHEA-S) in Mammalian Reproduction: Known Roles and Novel Paradigms. VITAMINS AND HORMONES 2018; 108:223-250. [PMID: 30029728 DOI: 10.1016/bs.vh.2018.02.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Steroid hormones form an integral part of normal development in mammalian organisms. Cholesterol is the parent compound from which all steroid hormones are synthesized. The product pregnenolone formed from cholesterol serves as precursor for mineralocorticoids, glucocorticoids, as well as dehydroepiandrosterone (DHEA) and its derived sexual hormones. DHEA assumes the prohormone status of a predominant endogenous precursor and a metabolic intermediate in ovarian follicular steroidogenesis. DHEA supplementation has been used to enhance ovarian reserve. Steroids like estradiol and testosterone have long been contemplated to play important roles in regulating meiotic maturation of oocytes in conjunction with gonadotropins. It is known that oocyte priming with estrogen is necessary to develop calcium (Ca2+) oscillations during maturation. Accruing evidence from diverse studies suggests that DHEA and its sulfate (dehydroepiandrosterone sulfate, DHEA-S) play significantly vital role not only as intermediates in androgen and estrogen formation, but may also be the probable 'oocyte factor' and behave as endogenous agonists triggering calcium oscillations for oocyte activation. DHEA/DHEA-S have been reported to regulate calcium channels for the passage of Ca2+ through the oocyte cytoplasm and for maintaining required threshold of Ca2+ oscillations. This role of DHEA/DHEA-S assumes critical significance in assisted reproductive technology and in-vitro fertilization treatment cycles where physical, chemical, and mechanical methods are employed for artificial oocyte activation to enhance fertilization rates. However, since these methods are invasive and may also cause adverse epigenetic modifications; oral or culture-media supplementation with DHEA/DHEA-S provides a noninvasive innate mechanism of in-vitro oocyte activation based on physiological metabolic pathway.
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67
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Sperm-borne phospholipase C zeta-1 ensures monospermic fertilization in mice. Sci Rep 2018; 8:1315. [PMID: 29358633 PMCID: PMC5778054 DOI: 10.1038/s41598-018-19497-6] [Citation(s) in RCA: 78] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Accepted: 01/03/2018] [Indexed: 12/23/2022] Open
Abstract
Sperm entry in mammalian oocytes triggers intracellular Ca2+ oscillations that initiate resumption of the meiotic cell cycle and subsequent activations. Here, we show that phospholipase C zeta 1 (PLCζ1) is the long-sought sperm-borne oocyte activation factor (SOAF). Plcz1 gene knockout (KO) mouse spermatozoa fail to induce Ca2+ changes in intracytoplasmic sperm injection (ICSI). In contrast to ICSI, Plcz1 KO spermatozoa induced atypical patterns of Ca2+ changes in normal fertilizations, and most of the fertilized oocytes ceased development at the 1–2-cell stage because of oocyte activation failure or polyspermy. We further discovered that both zona pellucida block to polyspermy (ZPBP) and plasma membrane block to polyspermy (PMBP) were delayed in oocytes fertilized with Plcz1 KO spermatozoa. With the observation that polyspermy is rare in astacin-like metalloendopeptidase (Astl) KO female oocytes that lack ZPBP, we conclude that PMPB plays more critical role than ZPBP in vivo. Finally, we obtained healthy pups from male mice carrying human infertile PLCZ1 mutation by single sperm ICSI supplemented with Plcz1 mRNA injection. These results suggest that mammalian spermatozoa have a primitive oocyte activation mechanism and that PLCζ1 is a SOAF that ensures oocyte activation steps for monospermic fertilization in mammals.
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68
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Satouh Y, Nozawa K, Yamagata K, Fujimoto T, Ikawa M. Viable offspring after imaging of Ca2+ oscillations and visualization of the cortical reaction in mouse eggs. Biol Reprod 2017; 96:563-575. [PMID: 28339615 DOI: 10.1093/biolre/iox002] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 01/27/2017] [Indexed: 11/14/2022] Open
Abstract
– During mammalian fertilization, egg Ca 2+ oscillations are known to play pivotal roles in triggering downstream events such as resumption of the cell cycle and the establishment of blocks to polyspermy. However, viable offspring have not been obtained after monitoring Ca 2+ oscillations, and their spatiotemporal links to subsequent events are still to be examined. Therefore, the development of imaging methods to avoid phototoxic damage while labeling these events is required. Here, we examined the usefulness of genetically encoded Ca 2+ indicators for optical imaging (GECOs), in combination with spinning-disk confocal imaging. The Ca 2+ imaging of fertilized mouse eggs with GEM-, G-, or R-GECO recorded successful oscillations (8.19 ± 0.31, 7.56 ± 0.23, or 7.53 ± 0.27 spikes in the first 2 h, respectively), similar to those obtained with chemical indicators. Then, in vitro viability tests revealed that imaging with G- or R-GECO did not interfere with the rate of development to the blastocyst stage (61.8 or 70.0%, respectively, vs 75.0% in control). Furthermore, two-cell transfer to recipient female mice after imaging with G- or R-GECO resulted in a similar birthrate (53.3 or 52.0%, respectively) to that of controls (48.7%). Next, we assessed the quality of the cortical reaction (CR) in artificially activated or fertilized eggs using fluorescently labeled Lens culinaris agglutinin fluorescein isothiocyanate. Multicolor imaging demonstrated that the first few Ca 2+ spikes are sufficient for the completion of the CR and subsequent hardening of the zona pellucida in mouse eggs. These methods provide a framework for studying Ca 2+ dynamics in mammalian fertilization.
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Affiliation(s)
- Yuhkoh Satouh
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Kaori Nozawa
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan.,Graduate School of Medicine, Osaka University, Suita, Osaka, Japan
| | - Kazuo Yamagata
- Department of Genetic Engineering, Faculty of Biology-Oriented Science and Technology, Kindai University, Kinokawa, Wakayama, Japan
| | - Takao Fujimoto
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan.,Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
| | - Masahito Ikawa
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan.,Graduate School of Medicine, Osaka University, Suita, Osaka, Japan.,Graduate School of Pharmaceutical Sciences, Osaka University, Suita, Osaka, Japan
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69
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Kashir J, Nomikos M, Lai FA. Phospholipase C zeta and calcium oscillations at fertilisation: The evidence, applications, and further questions. Adv Biol Regul 2017; 67:148-162. [PMID: 29108881 DOI: 10.1016/j.jbior.2017.10.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Revised: 10/25/2017] [Accepted: 10/25/2017] [Indexed: 12/26/2022]
Abstract
Oocyte activation is a fundamental event at mammalian fertilisation, initiated by a series of characteristic calcium (Ca2+) oscillations in mammals. This characteristic pattern of Ca2+ release is induced in a species-specific manner by a sperm-specific enzyme termed phospholipase C zeta (PLCζ). Reduction or absence of functional PLCζ within sperm underlies male factor infertility in humans, due to mutational inactivation or abrogation of PLCζ protein expression. Underlying such clinical implications, a significant body of evidence has now been accumulated that has characterised the unique biochemical and biophysical properties of this enzyme, further aiding the unique clinical opportunities presented. Herein, we present and discuss evidence accrued over the past decade and a half that serves to support the identity of PLCζ as the mammalian sperm factor. Furthermore, we also discuss the potential novel avenues that have yet to be examined regarding PLCζ mechanism of action in both the oocyte, and the sperm. Finally, we discuss the advances that have been made regarding the clinical therapeutic and diagnostic applications of PLCζ in potentially treating male infertility as a result of oocyte activation deficiency (OAD), and also possibly more general cases of male subfertility.
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Affiliation(s)
- Junaid Kashir
- College of Biomedical & Life Sciences, School of Biosciences, Cardiff University, Cardiff, UK; Alfaisal University, College of Medicine, Riyadh, Saudi Arabia; King Faisal Specialist Hospital & Research Center, Department of Comparative Medicine, Riyadh, Saudi Arabia.
| | - Michail Nomikos
- College of Medicine, Member of QU Health, Qatar University, PO Box 2713, Doha, Qatar
| | - F Anthony Lai
- College of Biomedical & Life Sciences, School of Biosciences, Cardiff University, Cardiff, UK; College of Medicine, Member of QU Health, Qatar University, PO Box 2713, Doha, Qatar.
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70
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Berridge MJ. Vitamin D deficiency: infertility and neurodevelopmental diseases (attention deficit hyperactivity disorder, autism, and schizophrenia). Am J Physiol Cell Physiol 2017; 314:C135-C151. [PMID: 29070492 DOI: 10.1152/ajpcell.00188.2017] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The process of development depends on a number of signaling systems that regulates the progressive sequence of developmental events. Infertility and neurodevelopmental diseases, such as attention deficit hyperactivity disorder, autism spectrum disorders, and schizophrenia, are caused by specific alterations in these signaling processes. Calcium signaling plays a prominent role throughout development beginning at fertilization and continuing through early development, implantation, and organ differentiation such as heart and brain development. Vitamin D plays a major role in regulating these signaling processes that control development. There is an increase in infertility and an onset of neurodevelopmental diseases when vitamin D is deficient. The way in which vitamin D deficiency acts to alter development is a major feature of this review. One of the primary functions of vitamin D is to maintain the phenotypic stability of both the Ca2+ and redox signaling pathways that play such a key role throughout development.
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Affiliation(s)
- Michael J Berridge
- Laboratory of Molecular Signalling, The Babraham Institute , Cambridge , United Kingdom
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71
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The role and mechanism of action of sperm PLC-zeta in mammalian fertilisation. Biochem J 2017; 474:3659-3673. [PMID: 29061915 DOI: 10.1042/bcj20160521] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 09/14/2017] [Accepted: 09/18/2017] [Indexed: 12/26/2022]
Abstract
At mammalian fertilisation, the fundamental stimulus that triggers oocyte (egg) activation and initiation of early embryonic development is an acute rise of the intracellular-free calcium (Ca2+) concentration inside the egg cytoplasm. This essential Ca2+ increase comprises a characteristic series of repetitive Ca2+ oscillations, starting soon after sperm-egg fusion. Over the last 15 years, accumulating scientific and clinical evidence supports the notion that the physiological stimulus that precedes the cytosolic Ca2+ oscillations is a novel, testis-specific phospholipase C (PLC) isoform, known as PLC-zeta (PLCζ). Sperm PLCζ catalyses the hydrolysis of phosphatidylinositol 4,5-bisphosphate triggering cytosolic Ca2+ oscillations through the inositol 1,4,5-trisphosphate signalling pathway. PLCζ is the smallest known mammalian PLC isoform with the most elementary domain organisation. However, relative to somatic PLCs, the PLCζ isoform possesses a unique potency in stimulating Ca2+ oscillations in eggs that is attributed to its novel biochemical characteristics. In this review, we discuss the latest developments that have begun to unravel the vital role of PLCζ at mammalian fertilisation and decipher its unique mechanism of action within the fertilising egg. We also postulate the significant potential diagnostic and therapeutic capacity of PLCζ in alleviating certain types of male infertility.
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72
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Ozil JP, Sainte-Beuve T, Banrezes B. [Mg 2+] o/[Ca 2+] o determines Ca 2+ response at fertilization: tuning of adult phenotype? Reproduction 2017; 154:675-693. [PMID: 28851827 DOI: 10.1530/rep-16-0057] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 08/15/2017] [Accepted: 08/29/2017] [Indexed: 01/09/2023]
Abstract
Alteration of the postnatal phenotype has sparked great concern about the developmental impact of culture media used at fertilization. However, the mechanisms and compounds involved are yet to be determined. Here, we used the Ca2+ responses from mouse eggs fertilized by ICSI as a dynamic and quantitative marker to understand the role of compounds in egg functioning and establish possible correlations with adult phenotypes. We computed 134 Ca2+ responses from the first to the last oscillation in media with specific formulations. Analyses demonstrate that eggs generated two times as many Ca2+ oscillations in KSOM as in M16 media (18.8 ± 7.0 vs 9.2 ± 2.5). Moreover, the time increment of the delay between two consecutive oscillations, named TIbO, is the most sensitive coefficient characterizing the mechanism that paces Ca2+ oscillations once the egg has been fertilized. Neither doubling external free Ca2+ nor dispermic fertilization increased significantly the total number of Ca2+ oscillations. In contrast, removing Mg2+ from the M16 boosted Ca2+ oscillations to 54.0 ± 35.2. Hence, [Mg2+]o/[Ca2+]o appears to determine the number, duration and frequency of the Ca2+ oscillations. These changes were correlated with long-term effects. The rate of female's growth was impacted with the 'KSOM' females having only half the fat deposit of 'M16' females. Moreover, adult animals issued from M16 had significantly smaller brain weight vs 'KSOM' and 'control' animals. TIbO is a new Ca2+ coefficient that gauges the very early functional impact of culture media. It offers the possibility of establishing correlations with postnatal consequences according to IVF medium formulation.Free French abstract: A French translation of this abstract is freely available at http://www.reproduction-online.org/content/154/5/675/suppl/DC2.
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Affiliation(s)
- Jean-Pierre Ozil
- UMR BDR, INRA, ENVA, Université Paris Saclay, Jouy en Josas, France
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73
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Hachem A, Godwin J, Ruas M, Lee HC, Ferrer Buitrago M, Ardestani G, Bassett A, Fox S, Navarrete F, de Sutter P, Heindryckx B, Fissore R, Parrington J. PLCζ is the physiological trigger of the Ca 2+ oscillations that induce embryogenesis in mammals but conception can occur in its absence. Development 2017; 144:2914-2924. [PMID: 28694258 DOI: 10.1242/dev.150227] [Citation(s) in RCA: 75] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Accepted: 07/01/2017] [Indexed: 12/21/2022]
Abstract
Activation of the egg by the sperm is the first, vital stage of embryogenesis. The sperm protein PLCζ has been proposed as the physiological agent that triggers the Ca2+ oscillations that normally initiate embryogenesis. Consistent with this, recombinant PLCζ induces Ca2+ oscillations in eggs and debilitating mutations in the PLCZ1 gene are associated with infertility in men. However, there has been no evidence that knockout of the gene encoding PLCζ abolishes the ability of sperm to induce Ca2+ oscillations in eggs. Here, we show that sperm derived from Plcz1-/- male mice fail to trigger Ca2+ oscillations in eggs, cause polyspermy and thus demonstrate that PLCζ is the physiological trigger of these Ca2+ oscillations. Remarkably, some eggs fertilized by PLCζ-null sperm can develop, albeit at greatly reduced efficiency, and after a significant time-delay. In addition, Plcz1-/- males are subfertile but not sterile, suggesting that in the absence of PLCζ, spontaneous egg activation can eventually occur via an alternative route. This is the first demonstration that in vivo fertilization without the normal physiological trigger of egg activation can result in offspring. PLCζ-null sperm now make it possible to resolve long-standing questions in fertilization biology, and to test the efficacy and safety of procedures used to treat human infertility.
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Affiliation(s)
- Alaa Hachem
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Jonathan Godwin
- Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Margarida Ruas
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Hoi Chang Lee
- Department of Veterinary and Animal Sciences, University of Massachusetts, 661 North Pleasant Street, Amherst, MA 01003-9286, USA
| | - Minerva Ferrer Buitrago
- Department for Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - Goli Ardestani
- Department of Veterinary and Animal Sciences, University of Massachusetts, 661 North Pleasant Street, Amherst, MA 01003-9286, USA
| | - Andrew Bassett
- Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK
| | - Sebastian Fox
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Felipe Navarrete
- Department of Veterinary and Animal Sciences, University of Massachusetts, 661 North Pleasant Street, Amherst, MA 01003-9286, USA
| | - Petra de Sutter
- Department for Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - Björn Heindryckx
- Department for Reproductive Medicine, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium
| | - Rafael Fissore
- Department of Veterinary and Animal Sciences, University of Massachusetts, 661 North Pleasant Street, Amherst, MA 01003-9286, USA
| | - John Parrington
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
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Fertilization 2: Polyspermic Fertilization. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 1001:105-123. [DOI: 10.1007/978-981-10-3975-1_7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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75
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Gat I, Orvieto R. "This is where it all started" - the pivotal role of PLCζ within the sophisticated process of mammalian reproduction: a systemic review. Basic Clin Androl 2017; 27:9. [PMID: 28533904 PMCID: PMC5438850 DOI: 10.1186/s12610-017-0054-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Accepted: 03/26/2017] [Indexed: 12/14/2022] Open
Abstract
Mammalian reproduction is one of the most complex and fascinating biological phenomenon, which aims to transfer maternal and paternal genetic material to the next generation. At the end of oogenesis and spermatogenesis, both haploid gametes contain a single set of chromosomes ready to form the zygote, the first cell of the newly developing individual. The mature oocyte and spermatozoa remain in a quiescent state, during which the oocyte is characterized by nuclear and cytoplasmic arrest, while the spermatozoa necessitates further maturation within the epididymis and female reproductive track prior to egg fertilization. Either in vivo or in vitro, the sperm initiates a series of irreversible biochemical and physiological modifications in the oocyte. The earliest detected signal after fertilization is cytosolic Ca2+ oscillations, a prerequisite step for embryo development. These oscillations trigger the release of the oocyte from the second meiosis arrest towards embryogenesis, also known as “oocyte activation”. Phospholipase C zeta (PLCζ) is a unique sperm-soluble protein responsible for triggering the InsP3/Ca2+ pathway within the oocyte, leading to Ca2+ oscillations and consequently to embryo development. The specific structure of PLCζ (compared to other PLCs) enables its specialized activity via the preserved X and Y catalytic domains, as well as distinct features such as rapid onset, high sensitivity to Ca2+ and cession of oscillations upon zygote formation. The emerging discoveries of PLCζ have stimulated studies focusing on the possible clinical applications of this protein in male infertility evaluation and management during IVF/ICSI. Fertilization failure is attributed to lack of oocyte second meiosis resumption, suggesting that ICSI failure may be related to impaired PLCζ activity. Microinjection of recombinant human PLCζ to human oocytes after ICSI fertilization failure may trigger Ca2+ oscillations and achieve successful fertilization, offering new hope for couples traditionally referred to sperm donation. However, more studies are still required prior to the routine implementation of this approach in the clinic. Directions for future studies are discussed.
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Affiliation(s)
- Itai Gat
- IVF Unit, Department of Obstetrics and Gynecology, Sheba Medical Center, Tel Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,Pinchas Borenstein Talpiot Medical Leadership Program, Sheba Medical Center, Tel Hashomer, Israel
| | - Raoul Orvieto
- IVF Unit, Department of Obstetrics and Gynecology, Sheba Medical Center, Tel Hashomer, Israel.,Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel.,The Tarnesby-Tarnowski Chair for Family Planning and Fertility Regulation, Sackler Faculty of Medicine, Tel Aviv, Israel
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76
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Zhu JQ, Tan SL, Taketo T. A lack of coordination between sister-chromatids segregation and cytokinesis in the oocytes of B6.Y TIR (XY) sex-reversed female mice. Sci Rep 2017; 7:960. [PMID: 28424461 PMCID: PMC5430445 DOI: 10.1038/s41598-017-00922-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 03/16/2017] [Indexed: 01/13/2023] Open
Abstract
The B6.YTIR (XY) mouse develops bilateral ovaries despite the expression of the testis-determining gene Sry during gonadal differentiation. We reported that the oocytes of the XY female are defective in their cytoplasm, resulting in a failure in the second meiotic division after activation or fertilization in vitro. However, the mechanism of meiotic failure or the cause of infertility remained to be clarified. In the present study, we obtained mature oocytes from XY females by superovulation and confirmed that these oocytes also fail in zygotic development. By using confocal microscopy 3D-analysis, we demonstrated that meiotic spindles were properly positioned and oriented in the MII-oocytes from XY females. After parthenogenic activation, fewer oocytes from XY females extruded the second polar body, and in those oocytes, sister-chromatids were often separated but neither set entered the second polar body. ARP2, F-actin, and ORC4, known to play roles in asymmetric meiotic division, were initially localized along the ooplasmic membrane and concentrated over the MII-spindle but lost their cortical polarity after activation while the sister-chromatids moved away from the oolemma in the oocytes from XY females. Our results indicate that the second polar body extrusion is uncoupled from the sister-chromatids separation in the oocytes from XY female mouse.
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Affiliation(s)
- Jia-Qiao Zhu
- Department of Obstetrics and Gynecology, McGill University, Montreal, Quebec, Canada.,College of Veterinary Medicine, Yangzhou University, Yangzhou, Jiangsu, P.R. China.,Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, Jiangsu, P.R. China
| | - Seang Lin Tan
- Department of Obstetrics and Gynecology, McGill University, Montreal, Quebec, Canada.,MUHC Reproductive Centre, Division of Reproductive Endocrinology and Infertility, McGill University, Montreal, Quebec, Canada.,OriginElle Fertility Clinic and Women's Health Centre, Montreal, Quebec, Canada
| | - Teruko Taketo
- Department of Obstetrics and Gynecology, McGill University, Montreal, Quebec, Canada. .,Department of Surgery, McGill University, Montreal, Quebec, Canada. .,Department of Biology, McGill University, Montreal, Quebec, Canada.
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77
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Yamaguchi T, Ito M, Kuroda K, Takeda S, Tanaka A. The establishment of appropriate methods for egg-activation by human PLCZ1 RNA injection into human oocyte. Cell Calcium 2017; 65:22-30. [PMID: 28320563 DOI: 10.1016/j.ceca.2017.03.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Revised: 03/03/2017] [Accepted: 03/03/2017] [Indexed: 01/29/2023]
Abstract
Phospholipase C-zeta (PLCZ1), a strong candidate of egg-activating sperm factor, can induce Ca2+ oscillations and cause egg activation. For the application of PLCZ1 to clinical use, we examined the pattern of Ca2+ responses and developmental rate by comparing PLCZ1 RNA injection methods with the other current methods, such as cytosolic aspiration, electrical stimulation and ionomycin treatment in human oocytes. We found that the pattern of Ca2+ oscillations after PLCZ1 RNA injection exhibited similar characteristics to that after ICSI treatment. We also determined the optimal concentration of human PLCZ1 RNA to activate the human oocytes. Our findings suggest that human PLCZ1 RNA is a better therapeutic agent to rescue human oocytes from failed activation, leading to normal and efficient development.
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Affiliation(s)
- Takashi Yamaguchi
- Saint Mother Obstetrics and Gynecology Clinic, Institute for ART, Fukuoka 807-0825, Japan; Department of Obstetrics and Gynecology, Juntendo University School of Medicine, Tokyo 113-0033, Japan
| | - Masahiko Ito
- Department of Virology and Parasitology, Hamamatsu University School of Medicine, Hamamatsu 431-3192, Japan.
| | - Keiji Kuroda
- Department of Obstetrics and Gynecology, Juntendo University School of Medicine, Tokyo 113-0033, Japan
| | - Satoru Takeda
- Department of Obstetrics and Gynecology, Juntendo University School of Medicine, Tokyo 113-0033, Japan
| | - Atsushi Tanaka
- Saint Mother Obstetrics and Gynecology Clinic, Institute for ART, Fukuoka 807-0825, Japan
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78
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Martin JH, Bromfield EG, Aitken RJ, Nixon B. Biochemical alterations in the oocyte in support of early embryonic development. Cell Mol Life Sci 2017; 74:469-485. [PMID: 27604868 PMCID: PMC11107538 DOI: 10.1007/s00018-016-2356-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 08/28/2016] [Accepted: 09/01/2016] [Indexed: 01/01/2023]
Abstract
Notwithstanding the enormous reproductive potential encapsulated within a mature mammalian oocyte, these cells present only a limited window for fertilization before defaulting to an apoptotic cascade known as post-ovulatory oocyte aging. The only cell with the capacity to rescue this potential is the fertilizing spermatozoon. Indeed, the union of these cells sets in train a remarkable series of events that endows the oocyte with the capacity to divide and differentiate into the trillions of cells that comprise a new individual. Traditional paradigms hold that, beyond the initial stimulation of fluctuating calcium (Ca2+) required for oocyte activation, the fertilizing spermatozoon plays limited additional roles in the early embryo. While this model has now been drawn into question in view of the recent discovery that spermatozoa deliver developmentally important classes of small noncoding RNAs and other epigenetic modulators to oocytes during fertilization, it is nevertheless apparent that the primary responsibility for oocyte activation rests with a modest store of maternally derived proteins and mRNA accumulated during oogenesis. It is, therefore, not surprising that widespread post-translational modifications, in particular phosphorylation, hold a central role in endowing these proteins with sufficient functional diversity to initiate embryonic development. Indeed, proteins targeted for such modifications have been linked to oocyte activation, recruitment of maternal mRNAs, DNA repair and resumption of the cell cycle. This review, therefore, seeks to explore the intimate relationship between Ca2+ release and the suite of molecular modifications that sweep through the oocyte to ensure the successful union of the parental germlines and ensure embryogenic fidelity.
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Affiliation(s)
- Jacinta H Martin
- Discipline of Biological Sciences and Priority Research Center for Reproductive Science, School of Environmental and Life Sciences, The University of Newcastle, University Drive, Callaghan, NSW, 2308, Australia.
| | - Elizabeth G Bromfield
- Discipline of Biological Sciences and Priority Research Center for Reproductive Science, School of Environmental and Life Sciences, The University of Newcastle, University Drive, Callaghan, NSW, 2308, Australia
| | - R John Aitken
- Discipline of Biological Sciences and Priority Research Center for Reproductive Science, School of Environmental and Life Sciences, The University of Newcastle, University Drive, Callaghan, NSW, 2308, Australia
| | - Brett Nixon
- Discipline of Biological Sciences and Priority Research Center for Reproductive Science, School of Environmental and Life Sciences, The University of Newcastle, University Drive, Callaghan, NSW, 2308, Australia
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A Unique Egg Cortical Granule Localization Motif Is Required for Ovastacin Sequestration to Prevent Premature ZP2 Cleavage and Ensure Female Fertility in Mice. PLoS Genet 2017; 13:e1006580. [PMID: 28114310 PMCID: PMC5293279 DOI: 10.1371/journal.pgen.1006580] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Revised: 02/06/2017] [Accepted: 01/12/2017] [Indexed: 12/03/2022] Open
Abstract
Monospermic fertilization is mediated by the extracellular zona pellucida composed of ZP1, ZP2 and ZP3. Sperm bind to the N-terminus of ZP2 which is cleaved after fertilization by ovastacin (encoded by Astl) exocytosed from egg cortical granules to prevent sperm binding. AstlNull mice lack the post-fertilization block to sperm binding and the ability to rescue this phenotype with AstlmCherry transgenic mice confirms the role of ovastacin in providing a definitive block to polyspermy. During oogenesis, endogenous ovastacin traffics through the endomembrane system prior to storage in peripherally located cortical granules. Deletion mutants of ovastacinmCherry expressed in growing oocytes define a unique 7 amino acid motif near its N-terminus that is necessary and sufficient for cortical granule localization. Deletion of the 7 amino acids by CRISPR/Cas9 at the endogenous locus (AstlΔ) prevents cortical granule localization of ovastacin. The misdirected enzyme is present within the endomembrane system and ZP2 is prematurely cleaved. Sperm bind poorly to the zona pellucida of AstlΔ/Δ mice with partially cleaved ZP2 and female mice are sub-fertile. Monospermic fertilization is essential for the onset of development. Egg cortical granules exocytose their contents after fertilization to prevent polyspermy by modifying the extracellular zona pellucida (ZP1, ZP2, ZP3). Little is known about the biology of these subcellular organelles which are unique to oocytes. Ovastacin, a zinc metalloendoprotease that cleaves ZP2 to prevent sperm binding, is a pioneer marker of mammalian cortical granules. ZP2 remains uncleaved in transgenic mice lacking ovastacin and sperm bind to the zona matrix independent of fertilization and cortical granule exocytosis. After documenting the rescue of the null phenotype with transgenic mice expressing fluorescently-tagged ovastacin, we defined a unique, well conserved, cortical granule localization motif using cRNA deletion mutants microinjected into mouse oocytes. The importance of the motif for localization to cortical granules was confirmed in vivo by deleting DNA encoding 7 amino acids of the endogenous locus with CRISPR/Cas9. Unexpectedly, mutant female mice were sub-fertile due to partial cleavage of ZP2 in the zona pellucida which prevented sperm from binding to ovulated eggs in vitro and in vivo. These observations offer unique insight into the molecular basis for translocation of proteins to cortical granules which is needed for successful, monospermic fertilization.
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80
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Fertility: Store-Operated Ca 2+ Entry in Germ Cells: Role in Egg Activation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2017; 993:577-593. [PMID: 28900934 DOI: 10.1007/978-3-319-57732-6_29] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
At the time of fertilization, the sperm activates the egg and induces embryonic development by triggering an elevation in the egg's intracellular free Ca2+ concentration. In mammals the initial Ca2+ rise is followed by a series of repetitive Ca2+ transients (known as oscillations) that last for several hours. Although the source of Ca2+ during the signaling process is primarily the egg's smooth endoplasmic reticulum, the oscillations stop in the absence of extracellular Ca2+ indicating that a Ca2+ influx across the plasma membrane is essential to sustain them. Depletion of the intracellular stores using specific inhibitors generates a Ca2+ entry across the plasma membrane of eggs of various species, and a continuous influx of Ca2+ has been linked to the sperm-induced Ca2+ oscillations in the mouse; these data indicate that store-operated Ca2+ entry (SOCE) operates in eggs and may be the mechanism that maintains the long-lasting Ca2+ signal at fertilization. Recent findings suggest that the signaling proteins STIM1 and Orai1 are present in eggs; they are responsible for mediating SOCE, and their functions are essential for proper Ca2+ signaling at fertilization to support normal embryo development.
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81
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Nakai M, Ito J, Suzuki SI, Fuchimoto DI, Sembon S, Suzuki M, Noguchi J, Kaneko H, Onishi A, Kashiwazaki N, Kikuchi K. Lack of calcium oscillation causes failure of oocyte activation after intracytoplasmic sperm injection in pigs. J Reprod Dev 2016; 62:615-621. [PMID: 27725347 PMCID: PMC5177980 DOI: 10.1262/jrd.2016-113] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In pigs, the efficiency of embryo production after intracytoplasmic sperm injection (ICSI) is still low because of frequent failure of normal fertilization,
which involves formation of two polar bodies and two pronuclei. To clarify the reasons for this, we hypothesized that ICSI does not properly trigger
sperm-induced fertilization events, especially intracellular Ca2+ signaling, also known as Ca2+ oscillation. We also suspected that the
use of in vitro-matured oocytes might negatively affect fertilization events and embryonic development of sperm-injected oocytes. Therefore, we
compared the patterns of Ca2+ oscillation, the efficiency of oocyte activation and normal fertilization, and embryo development to the blastocyst
stage among in vivo- or in vitro-matured oocytes after ICSI or in vitro fertilization (IVF). Unexpectedly, we
found that the pattern of Ca2+ oscillation, such as the frequency and amplitude of Ca2+ rises, in oocytes after ICSI was similar to that
in oocytes after IVF, irrespective of the oocyte source. However, half of the oocytes failed to become activated after ICSI and showed no Ca2+
oscillation. Moreover, the embryonic development of normal fertilized oocytes was reduced when in vitro-matured oocytes were used, irrespective
of the fertilization method employed. These findings suggest that low embryo production efficiency after ICSI is attributable mainly to poor developmental
ability of in vitro-matured oocytes and a lack of Ca2+ oscillation, rather than the pattern of oscillation.
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Affiliation(s)
- Michiko Nakai
- Division of Animal Sciences, Institute of Agrobiological Sciences, National Agriculture and Food Research Organization, Ibaraki 305-8602, Japan
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82
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MORITA Y, TANIGUCHI M, TANIHARA F, ITO A, NAMULA Z, DO LTK, TAKAGI M, TAKEMOTO T, OTOI T. The optimal period of Ca-EDTA treatment for parthenogenetic activation of porcine oocytes during maturation culture. J Vet Med Sci 2016; 78:1019-23. [PMID: 26947170 PMCID: PMC4937136 DOI: 10.1292/jvms.15-0658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 02/22/2016] [Indexed: 11/22/2022] Open
Abstract
The changes triggered by sperm-induced activation of oocytes, which are required for normal oocyte development, can be mediated by other agents, thereby inducing the parthenogenesis. In this study, we exposed porcine oocytes to 1 mM Ca-EDTA, a metal-ion chelator, at various intervals during 48 hr of in vitro maturation to determine the optimum period of Ca-EDTA treatment for parthenogenetic activation. When the oocytes were cultured with or without Ca-EDTA from 36 hr (post-12), 24 hr (post-24), 12 hr (post-36) and 0 hr (post-48) after the start of maturation culture, the blastocyst formation rates were significantly higher (P<0.05) in the post-24, post-36 and post-48 groups (3.3%, 4.0% and 2.6%, respectively) than those in the control group without treatment (0%). Furthermore, when the oocytes were cultured with Ca-EDTA for 0 hr (control), 12 hr (pre-12), 24 hr (pre-24), 36 hr (pre-36) and 48 hr (pre-48) from the start of maturation culture, the oocytes formed blastocysts only in the pre-36 and pre-48 groups (0.4% or 0.8%, respectively). Pronuclei (<66.7%) were observed only when the periods of Ca-EDTA treatment were more than 12 hr during maturation culture. In the control group, no pronuclei were detected. Our findings demonstrate that porcine immature oocytes can be parthenogenetically activated by Ca-EDTA treatment for at least 24 hr to 36 hr during maturation culture, leading to pronucleus formation followed by the formation of blastocysts.
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Affiliation(s)
- Yasuhiro MORITA
- The United Graduate School of Veterinary Science, Yamaguchi University,
Yamaguchi 753–8515, Japan
| | - Masayasu TANIGUCHI
- The United Graduate School of Veterinary Science, Yamaguchi University,
Yamaguchi 753–8515, Japan
| | - Fuminori TANIHARA
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770–8501,
Japan
| | - Aya ITO
- The United Graduate School of Veterinary Science, Yamaguchi University,
Yamaguchi 753–8515, Japan
| | - Zhao NAMULA
- The United Graduate School of Veterinary Science, Yamaguchi University,
Yamaguchi 753–8515, Japan
| | - Lanh Thi Kim DO
- The United Graduate School of Veterinary Science, Yamaguchi University,
Yamaguchi 753–8515, Japan
| | - Mitsuhiro TAKAGI
- The United Graduate School of Veterinary Science, Yamaguchi University,
Yamaguchi 753–8515, Japan
| | - Tatsuya TAKEMOTO
- Division of Embryology, Fujii Memorial Institute of Medical Sciences, Tokushima
University, Tokushima 770–8503, Japan
| | - Takeshige OTOI
- Faculty of Bioscience and Bioindustry, Tokushima University, Tokushima 770–8501,
Japan
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83
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Bury L, Coelho PA, Glover DM. From Meiosis to Mitosis: The Astonishing Flexibility of Cell Division Mechanisms in Early Mammalian Development. Curr Top Dev Biol 2016; 120:125-71. [PMID: 27475851 DOI: 10.1016/bs.ctdb.2016.04.011] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The execution of female meiosis and the establishment of the zygote is arguably the most critical stage of mammalian development. The egg can be arrested in the prophase of meiosis I for decades, and when it is activated, the spindle is assembled de novo. This spindle must function with the highest of fidelity and yet its assembly is unusually achieved in the absence of conventional centrosomes and with minimal influence of chromatin. Moreover, its dramatic asymmetric positioning is achieved through remarkable properties of the actin cytoskeleton to ensure elimination of the polar bodies. The second meiotic arrest marks a uniquely prolonged metaphase eventually interrupted by egg activation at fertilization to complete meiosis and mark a period of preparation of the male and female pronuclear genomes not only for their entry into the mitotic cleavage divisions but also for the imminent prospect of their zygotic expression.
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Affiliation(s)
- L Bury
- University of Cambridge, Cambridge, United Kingdom.
| | - P A Coelho
- University of Cambridge, Cambridge, United Kingdom
| | - D M Glover
- University of Cambridge, Cambridge, United Kingdom
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84
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Darbandi S, Darbandi M, Khorshid HRK, Sadeghi MR, Al-Hasani S, Agarwal A, Shirazi A, Heidari M, Akhondi MM. Experimental strategies towards increasing intracellular mitochondrial activity in oocytes: A systematic review. Mitochondrion 2016; 30:8-17. [PMID: 27234976 DOI: 10.1016/j.mito.2016.05.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 04/04/2016] [Accepted: 05/20/2016] [Indexed: 12/19/2022]
Abstract
PURPOSE The mitochondrial complement is critical in sustaining the earliest stages of life. To improve the Assisted Reproductive Technology (ART), current methods of interest were evaluated for increasing the activity and copy number of mitochondria in the oocyte cell. METHODS This covered the researches from 1966 to September 2015. RESULTS The results provided ten methods that can be studied individually or simultaneously. CONCLUSION Though the use of these techniques generated great concern about heteroplasmy observation in humans, it seems that with study on these suggested methods there is real hope for effective treatments of old oocyte or oocytes containing mitochondrial problems in the near future.
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Affiliation(s)
- Sara Darbandi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
| | - Mahsa Darbandi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
| | | | - Mohammad Reza Sadeghi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
| | - Safaa Al-Hasani
- Reproductive Medicine Unit, University of Schleswig-Holstein, Luebeck, Germany.
| | - Ashok Agarwal
- Center for Reproductive Medicine, Glickman Urological and Kidney Institute, Cleveland Clinic, Cleveland, OH, USA.
| | - Abolfazl Shirazi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
| | - Mahnaz Heidari
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran. M.@avicenna.ar.ir
| | - Mohammad Mehdi Akhondi
- Reproductive Biotechnology Research Center, Avicenna Research Institute, ACECR, Tehran, Iran.
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85
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The zinc spark is an inorganic signature of human egg activation. Sci Rep 2016; 6:24737. [PMID: 27113677 PMCID: PMC4845039 DOI: 10.1038/srep24737] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Accepted: 04/01/2016] [Indexed: 12/04/2022] Open
Abstract
Egg activation refers to events required for transition of a gamete into an embryo, including establishment of the polyspermy block, completion of meiosis, entry into mitosis, selective recruitment and degradation of maternal mRNA, and pronuclear development. Here we show that zinc fluxes accompany human egg activation. We monitored calcium and zinc dynamics in individual human eggs using selective fluorophores following activation with calcium-ionomycin, ionomycin, or hPLCζ cRNA microinjection. These egg activation methods, as expected, induced rises in intracellular calcium levels and also triggered the coordinated release of zinc into the extracellular space in a prominent “zinc spark.” The ability of the gamete to mount a zinc spark response was meiotic-stage dependent. Moreover, chelation of intracellular zinc alone was sufficient to induce cell cycle resumption and transition of a meiotic cell into a mitotic one. Together, these results demonstrate critical functions for zinc dynamics and establish the zinc spark as an extracellular marker of early human development.
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86
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Lopez RA, Renzaglia KS. Arabinogalactan proteins and arabinan pectins abound in the specialized matrices surrounding female gametes of the fern Ceratopteris richardii. PLANTA 2016; 243:947-957. [PMID: 26739842 DOI: 10.1007/s00425-015-2448-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 12/15/2015] [Indexed: 06/05/2023]
Abstract
Both male and female gametes of archegoniates are highly specialized cells surrounded by an extraprotoplasmic matrix rich in AGPs, which are speculated to facilitate development and gamete fusion through Ca 2+) oscillations. An additional layer, the egg envelope, forms around the egg periphery, except at the fertilization pore, and contains arabinose-rich polymers that presumably impart flexibility for the rapidly growing zygote and embryo. The abundant AGPs and arabinan pectins associated with the eggs of C. richardii not only are integral to development, fertilization, and early embryogenesis, but also may be involved in desiccation tolerance important to the survival of the reproductive gametophyte. A defining feature of gametogenesis in archegoniates is the deposition of a special matrix outside of the plasmalemma of both egg and sperm cells that displaces the primary cell wall away from the protoplasm. It is within this matrix that gamete differentiation occurs. In leptosporangiate ferns, maturation of the egg cell involves the deposition of a second specialized wall, the so-called egg envelope that surrounds the cell except at the fertilization pore, a narrow site where gamete fusion takes place. We provide the first conclusive evidence of the macromolecular constituents in the unique structures surrounding fern egg cells before and after fertilization. To test the hypotheses that the egg extracellular matrix contains arabinogalactan proteins (AGPs) as does the sperm cell matrix, and that cell wall polysaccharides, especially pectins, are components of the egg envelope, we examined the expression patterns of AGPs and cell wall constituents during oogenesis in Ceratopteris richardii. Utilizing histochemical stains for callose, cellulose and AGPs coupled with immunogold localizations employing a suite of monoclonal antibodies to cell wall components (JIM13, JIM8, LM2, LM5, LM6, LM19, LM20 and anticallose), we demonstrate that AGPs, but not pectins, are abundant in the matrix around egg cells and degrading neck canal and ventral canal cells during archegonial development. A striking finding is that both AGPs and (1,5)-α-L-arabinan pectin epitopes are principle components of the egg envelope before and after fertilization, suggesting that they are important in both egg maturation and gamete fusion.
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Affiliation(s)
- Renee A Lopez
- Department of Plant Biology, MC: 6509, Southern Illinois University Carbondale, Carbondale, IL, 62901, USA.
| | - Karen S Renzaglia
- Department of Plant Biology, MC: 6509, Southern Illinois University Carbondale, Carbondale, IL, 62901, USA
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87
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Haverfield J, Nakagawa S, Love D, Tsichlaki E, Nomikos M, Lai FA, Swann K, FitzHarris G. Ca(2+) dynamics in oocytes from naturally-aged mice. Sci Rep 2016; 6:19357. [PMID: 26785810 PMCID: PMC4726220 DOI: 10.1038/srep19357] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 12/11/2015] [Indexed: 12/18/2022] Open
Abstract
The ability of human metaphase-II arrested eggs to activate following fertilisation declines with advancing maternal age. Egg activation is triggered by repetitive increases in intracellular Ca2+ concentration ([Ca2+]i) in the ooplasm as a result of sperm-egg fusion. We therefore hypothesised that eggs from older females feature a reduced ability to mount appropriate Ca2+ responses at fertilisation. To test this hypothesis we performed the first examination of Ca2+ dynamics in eggs from young and naturally-aged mice. Strikingly, we find that Ca2+ stores and resting [Ca2+]i are unchanged with age. Although eggs from aged mice feature a reduced ability to replenish intracellular Ca2+ stores following depletion, this difference had no effect on the duration, number, or amplitude of Ca2+ oscillations following intracytoplasmic sperm injection or expression of phospholipase C zeta. In contrast, we describe a substantial reduction in the frequency and duration of oscillations in aged eggs upon parthenogenetic activation with SrCl2. We conclude that the ability to mount and respond to an appropriate Ca2+ signal at fertilisation is largely unchanged by advancing maternal age, but subtle changes in Ca2+ handling occur that may have more substantial impacts upon commonly used means of parthenogenetic activation.
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Affiliation(s)
- Jenna Haverfield
- Centre Recherche Centre Hospitalier Université de Montréal, Montreal, Québec, Canada, H2X 0A9.,Department of Obstetrics and Gynaecology, University of Montréal, Montréal, Québec, Canada, H3T 1J4
| | - Shoma Nakagawa
- Centre Recherche Centre Hospitalier Université de Montréal, Montreal, Québec, Canada, H2X 0A9
| | - Daniel Love
- Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, UK, CF14 4XN
| | - Elina Tsichlaki
- Department of Cell and Developmental Biology, University College London, London, UK, WC1E 6BT
| | - Michail Nomikos
- Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, UK, CF14 4XN
| | - F Anthony Lai
- Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, UK, CF14 4XN
| | - Karl Swann
- Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, UK, CF14 4XN
| | - Greg FitzHarris
- Centre Recherche Centre Hospitalier Université de Montréal, Montreal, Québec, Canada, H2X 0A9.,Department of Obstetrics and Gynaecology, University of Montréal, Montréal, Québec, Canada, H3T 1J4.,Department of Cell and Developmental Biology, University College London, London, UK, WC1E 6BT
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88
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Abstract
In mammalian species, including human, fertilization is characterized by the triggering of long-lasting calcium (Ca(2+)) oscillations in the egg cytoplasm. The monitoring of these Ca(2+) oscillations is a valuable technique to demonstrate that fertilization has occurred, to study egg activation events elicited downstream of the Ca(2+) signal, as well as to evaluate sperm quality. This chapter describes our protocol to monitor sperm-induced Ca(2+) oscillations in mouse eggs, using fluorescence microscopy techniques and the Fura-2-AM ratiometric Ca(2+) indicator.
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Affiliation(s)
- Guillaume Halet
- CNRS UMR6290, Institut de Génétique et Développement de Rennes, Université Rennes 1, 2 Avenue du Professeur LéonBernard, Rennes Cedex, 35043, France.
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89
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Abstract
The most fundamental unresolved issue of fertilization is to define how the sperm activates the egg to begin embryo development. Egg activation at fertilization in all species thus far examined is caused by some form of transient increase in the cytoplasmic free Ca2+ concentration. What has not been clear, however, is precisely how the sperm triggers the large changes in Ca2+ observed within the egg cytoplasm. Here, we review the studies indicating that the fertilizing sperm stimulates a cytosolic Ca2+ increase in the egg specifically by delivering a soluble factor that diffuses into the cytosolic space of the egg upon gamete membrane fusion. Evidence is primarily considered in species of eggs where the sperm has been shown to elicit a cytosolic Ca2+ increase by initiating Ca2+ release from intracellular Ca2+ stores. We suggest that our best understanding of these signaling events is in mammals, where the sperm triggers a prolonged series of intracellular Ca2+ oscillations. The strongest empirical studies to date suggest that mammalian sperm-triggered Ca2+ oscillations are caused by the introduction of a sperm-specific protein, called phospholipase C-zeta (PLCζ) that generates inositol trisphosphate within the egg. We will discuss the role and mechanism of action of PLCζ in detail at a molecular and cellular level. We will also consider some of the evidence that a soluble sperm protein might be involved in egg activation in nonmammalian species.
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Affiliation(s)
- Karl Swann
- College of Biomedical and Life Sciences, School of Medicine, Cardiff University, Cardiff, United Kingdom
| | - F. Anthony Lai
- College of Biomedical and Life Sciences, School of Medicine, Cardiff University, Cardiff, United Kingdom
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90
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Lee HC, Yoon SY, Lykke-Hartmann K, Fissore RA, Carvacho I. TRPV3 channels mediate Ca2+ influx induced by 2-APB in mouse eggs. Cell Calcium 2016; 59:21-31. [DOI: 10.1016/j.ceca.2015.12.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 12/09/2015] [Accepted: 12/11/2015] [Indexed: 11/29/2022]
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91
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Shu L, Laurila A, Räsänen K. Acid stress mediated adaptive divergence in ion channel function during embryogenesis in Rana arvalis. Sci Rep 2015; 5:14201. [PMID: 26381453 PMCID: PMC4585641 DOI: 10.1038/srep14201] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2015] [Accepted: 08/19/2015] [Indexed: 02/01/2023] Open
Abstract
Ion channels and pumps are responsible for ion flux in cells, and are key mechanisms mediating cellular function. Many environmental stressors, such as salinity and acidification, are known to severely disrupt ionic balance of organisms thereby challenging fitness of natural populations. Although ion channels can have several vital functions during early life-stages (e.g. embryogenesis), it is currently not known i) how developing embryos maintain proper intracellular conditions when exposed to environmental stress and ii) to what extent environmental stress can drive intra-specific divergence in ion channels. Here we studied the moor frog, Rana arvalis, from three divergent populations to investigate the role of different ion channels and pumps for embryonic survival under acid stress (pH 4 vs 7.5) and whether populations adapted to contrasting acidities differ in the relative role of different ion channel/pumps. We found that ion channels that mediate Ca(2+) influx are essential for embryonic survival under acidic pH, and, intriguingly, that populations differ in calcium channel function. Our results suggest that adaptive divergence in embryonic acid stress tolerance of amphibians may in part be mediated by Ca(2+) balance. We suggest that ion flux may mediate adaptive divergence of natural populations at early life-stages in the face of environmental stress.
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Affiliation(s)
- Longfei Shu
- Eawag, Department of Aquatic Ecology, Switzerland and ETH Zurich, Institute of Integrative Biology, Switzerland
| | - Anssi Laurila
- Animal Ecology/Department of Ecology and Genetics, Evolutionary Biology Center, Uppsala University, Sweden
| | - Katja Räsänen
- Eawag, Department of Aquatic Ecology, Switzerland and ETH Zurich, Institute of Integrative Biology, Switzerland
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92
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Amdani SN, Yeste M, Jones C, Coward K. Sperm Factors and Oocyte Activation: Current Controversies and Considerations1. Biol Reprod 2015; 93:50. [DOI: 10.1095/biolreprod.115.130609] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 06/30/2015] [Indexed: 11/01/2022] Open
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93
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Zhang N, Yoon SY, Parys JB, Fissore RA. Effect of M-phase kinase phosphorylations on type 1 inositol 1,4,5-trisphosphate receptor-mediated Ca2+ responses in mouse eggs. Cell Calcium 2015; 58:476-88. [PMID: 26259730 DOI: 10.1016/j.ceca.2015.07.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 07/28/2015] [Accepted: 07/30/2015] [Indexed: 12/26/2022]
Abstract
The type 1 inositol 1,4,5-trisphosphate receptor (IP3R1) mediates increases in the intracellular concentration of Ca(2+) ([Ca(2+)]i) during fertilization in mammalian eggs. The activity of IP3R1 is enhanced during oocyte maturation, and phosphorylations by M-phase kinases are thought to positively regulate the activity of IP3R1. Accordingly, we and others have found that IP3R1 is phosphorylated at S(421), T(799) (by Cdk1) and at S(436) (by ERK). Nevertheless, the effects of these phosphorylations on the function of the receptor and their impact on [Ca(2+)]i oscillations in eggs have not been clearly examined. To address this, we expressed in mouse oocytes an IP3R1 variant with the three indicated phosphorylation sites replaced by acidic residues, IIIE-IP3R1, such that it would act like a constitutively phosphorylated IP3R1, and examined [Ca(2+)]i parameters in response to stimuli. We found that overexpression of wild type (wt-IP3R1) or IIIE-IP3R1 in oocytes containing endogenous receptors caused dominant negative-like effects on Ca(2+) release and oscillations. Therefore, we first selectively removed the endogenous IP3R1, and subsequently expressed the exogenous receptors. We found that in response to injection of PLCζ cRNA, eggs without endogenous IP3R1 failed to mount persistent Ca(2+) oscillations, although expression of wt-IP3R1 restored their [Ca(2+)]i oscillatory activity. We also observed that the Ca(2+) oscillatory ability and the sensitivity to IP3 in eggs expressing IIIE-IP3R1 were greater than in those expressing wt-IP3R1. Lastly, we found that exogenous IP3R1s are resistant to downregulation and support longer oscillations and of higher amplitude. Altogether, our results show that phosphorylations by Cdk1 and MAPK enhance the activity of IP3R1, which is consistent with its maximal activity observed at the time of fertilization and the role of Ca(2+) release in egg activation.
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Affiliation(s)
- Nan Zhang
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003, USA; Department of Obstetrics and Gynecology, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
| | - Sook Young Yoon
- Fertility Center of CHA Gangnam Medical Center, College of Medicine, CHA University, Seoul 135-081, Republic of Korea
| | - Jan B Parys
- KU Leuven, Laboratory of Molecular and Cellular Signaling, Department of Cellular and Molecular Medicine, Campus Gasthuisberg O/N-I box 802, Herestraat 49, BE-3000 Leuven, Belgium
| | - Rafael A Fissore
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, MA 01003, USA.
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94
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Svoboda P, Franke V, Schultz RM. Sculpting the Transcriptome During the Oocyte-to-Embryo Transition in Mouse. Curr Top Dev Biol 2015; 113:305-49. [PMID: 26358877 DOI: 10.1016/bs.ctdb.2015.06.004] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In mouse, the oocyte-to-embryo transition entails converting a highly differentiated oocyte to totipotent blastomeres. This transition is driven by degradation of maternal mRNAs, which results in loss of oocyte identity, and reprogramming of gene expression during the course of zygotic gene activation, which occurs primarily during the two-cell stage and confers blastomere totipotency. Full-grown oocytes are transcriptionally quiescent and mRNAs are remarkably stable in oocytes due to the RNA-binding protein MSY2, which stabilizes mRNAs, and low activity of the 5' and 3' RNA degradation machinery. Oocyte maturation initiates a transition from mRNA stability to instability due to phosphorylation of MSY2, which makes mRNAs more susceptible to the RNA degradation machinery, and recruitment of dormant maternal mRNAs that encode for critical components of the 5' and 3' RNA degradation machinery. Small RNAs (miRNA, siRNA, and piRNA) play little, if any, role in mRNA degradation that occurs during maturation. Many mRNAs are totally degraded but a substantial fraction is only partially degraded, their degradation completed by the end of the two-cell stage. Genome activation initiates during the one-cell stage, is promiscuous, low level, and genome wide (and includes both inter- and intragenic regions) and produces transcripts that are inefficiently spliced and polyadenylated. The major wave of genome activation in two-cell embryos involves expression of thousands of new genes. This unique pattern of gene expression is the product of maternal mRNAs recruited during maturation that encode for transcription factors and chromatin remodelers, as well as dramatic changes in chromatin structure due to incorporation of histone variants and modified histones.
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Affiliation(s)
- Petr Svoboda
- Institute of Molecular Genetics, Academy of Sciences of the Czech Republic, Prague, Czech Republic.
| | - Vedran Franke
- Bioinformatics Group, Division of Biology, Faculty of Science, Zagreb University, Zagreb, Croatia
| | - Richard M Schultz
- Department of Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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95
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Phospholipase C-zeta deficiency as a cause for repetitive oocyte fertilization failure during ovarian stimulation for in vitro fertilization with ICSI: a case report. J Assist Reprod Genet 2015; 32:1415-9. [PMID: 26174123 DOI: 10.1007/s10815-015-0531-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2015] [Accepted: 06/30/2015] [Indexed: 10/23/2022] Open
Abstract
PURPOSE The purpose of this study is to describe impaired oocyte fertilization from phospholipase C-zeta (PLC-ζ) deficiency in normal-appearing sperm that was successfully treated using calcium (Ca(2+)) ionophore with intracytoplasmic sperm injection (ICSI) of oocytes matured in vitro. METHODS An infertile couple undergoing in vitro fertilization (IVF) experienced failed oocyte fertilization following ICSI with normal-appearing sperm. A semen sample collected from the patient was used to assess the expression of sperm PLC- ζ protein by Western blot analysis and immunofluorescence and PLC-ζ bioactivity by an in vitro model of Ca(2+) release. A second IVF cycle was performed using Ca(2+) ionophore with ICSI to enhance Ca(2+)-induced oocyte activation of oocytes matured in vitro. RESULTS Sperm PLC-ζ protein deficiency was demonstrated by Western blot analysis and immunofluorescence and confirmed by reduced PLC-ζ bioactivity using an in vitro model of Ca(2+) release. Nevertheless, with this sperm and supplementation of Ca(2+) ionophore following ICSI, fertilization of four of six oocytes matured in vitro was obtained. In addition, four embryos underwent cleavage and two of them reached the blastocyst stage. Transfer of these blastocysts into the uterus led to a single pregnancy and live birth. CONCLUSIONS Deficiency of PLC-ζ in normal-appearing human sperm is associated with impaired Ca(2+)-dependent oocyte activation during ICSI. Under this condition, use of Ca(2+) ionophore following ICSI of oocytes matured in vitro improves embryo developmental competence, possibly through the activation of Ca(2+)-dependent mechanisms governing fertilization and preimplantation embryogenesis.
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96
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Bernhardt ML, Lowther KM, Padilla-Banks E, McDonough CE, Lee KN, Evsikov AV, Uliasz TF, Chidiac P, Williams CJ, Mehlmann LM. Regulator of G-protein signaling 2 (RGS2) suppresses premature calcium release in mouse eggs. Development 2015; 142:2633-40. [PMID: 26160904 DOI: 10.1242/dev.121707] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 06/25/2015] [Indexed: 11/20/2022]
Abstract
During oocyte maturation, capacity and sensitivity of Ca(2+) signaling machinery increases dramatically, preparing the metaphase II (MII)-arrested egg for fertilization. Upon sperm-egg fusion, Ca(2+) release from IP3-sensitive endoplasmic reticulum stores results in cytoplasmic Ca(2+) oscillations that drive egg activation and initiate early embryo development. Premature Ca(2+) release can cause parthenogenetic activation prior to fertilization; thus, preventing inappropriate Ca(2+) signaling is crucial for ensuring robust MII arrest. Here, we show that regulator of G-protein signaling 2 (RGS2) suppresses Ca(2+) release in MII eggs. Rgs2 mRNA was recruited for translation during oocyte maturation, resulting in ∼ 20-fold more RGS2 protein in MII eggs than in fully grown immature oocytes. Rgs2-siRNA-injected oocytes matured to MII; however, they had increased sensitivity to low pH and acetylcholine (ACh), which caused inappropriate Ca(2+) release and premature egg activation. When matured in vitro, RGS2-depleted eggs underwent spontaneous Ca(2+) increases that were sufficient to cause premature zona pellucida conversion. Rgs2(-/-) females had reduced litter sizes, and their eggs had increased sensitivity to low pH and ACh. Rgs2(-/-) eggs also underwent premature zona pellucida conversion in vivo. These findings indicate that RGS2 functions as a brake to suppress premature Ca(2+) release in eggs that are poised on the brink of development.
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Affiliation(s)
- Miranda L Bernhardt
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Katie M Lowther
- Department of Cell Biology, UConn Health, Farmington, CT 06030, USA
| | - Elizabeth Padilla-Banks
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Caitlin E McDonough
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Katherine N Lee
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A 5C1
| | - Alexei V Evsikov
- Department of Molecular Medicine, University of South Florida, Tampa, FL 33612, USA
| | - Tracy F Uliasz
- Department of Cell Biology, UConn Health, Farmington, CT 06030, USA
| | - Peter Chidiac
- Department of Physiology and Pharmacology, Schulich School of Medicine and Dentistry, University of Western Ontario, London, Ontario, Canada N6A 5C1
| | - Carmen J Williams
- Reproductive and Developmental Biology Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Lisa M Mehlmann
- Department of Cell Biology, UConn Health, Farmington, CT 06030, USA
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97
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Lee K, Davis A, Zhang L, Ryu J, Spate LD, Park KW, Samuel MS, Walters EM, Murphy CN, Machaty Z, Prather RS. Pig oocyte activation using a Zn²⁺ chelator, TPEN. Theriogenology 2015; 84:1024-32. [PMID: 26143360 DOI: 10.1016/j.theriogenology.2015.05.036] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 05/21/2015] [Accepted: 05/27/2015] [Indexed: 02/03/2023]
Abstract
Artificial oocyte activation is a critical step during SCNT. Most current activation protocols focus on inducing an increase in the intracellular free Ca(2+) concentration of the oocyte. Here, we have used a zinc chelator, TPEN, to enhance the efficiency of oocyte activation during SCNT. TPEN treatment of matured pig oocytes resulted in the reduction of available Zn(2+) in pig oocytes; however, the cytosolic Ca(2+) concentration in the oocytes was not affected by the TPEN treatment. When various concentrations (100-250 μM) and incubation durations (45 minutes-2.5 hours) of TPEN were used to activate oocytes, the efficiency of oocyte activation was not different from conventional activation methods. When oocytes that were activated by conventional activation methods were incubated with a lower concentration of TPEN (5-10 μM), a significant increase in embryos developing to the blastocyst stage was observed. In addition, when oocytes receiving a small Ca(2+) stimulus were further activated by higher concentration of TPEN (100-200 μM), a significant increase in the frequency of blastocyst formation was observed, compared to a conventional activation method. This result indicated that TPEN can be a main reagent in oocyte activation. No increase in the cytosolic Ca(2+) level was detected when oocytes were exposed to various concentrations of TPEN, indicating the ability of TPEN to induce oocyte activation is independent of an intracellular Ca(2+) increase. We were able to produce clones through SCNT by using the TPEN-assisted activation procedure, and the piglets produced through the process did not show any signs of abnormality. In this study, we have developed an efficient way to use TPEN to increase the developmental potential of cloned embryos.
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Affiliation(s)
- Kiho Lee
- Division of Animal Science, University of Missouri, Columbia, Missouri, USA; Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, USA.
| | - Alyssa Davis
- Division of Animal Science, University of Missouri, Columbia, Missouri, USA
| | - Lu Zhang
- Department of Animal Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Junghyun Ryu
- Department of Animal and Poultry Sciences, Virginia Tech, Blacksburg, USA
| | - Lee D Spate
- Division of Animal Science, University of Missouri, Columbia, Missouri, USA
| | - Kwang-Wook Park
- Division of Animal Science, University of Missouri, Columbia, Missouri, USA; Department of Animal Science and Technology, Sunchon National University, Suncheon, Jeonnam, Republic of Korea
| | - Melissa S Samuel
- Division of Animal Science, University of Missouri, Columbia, Missouri, USA; National Swine Resource and Research Center, University of Missouri, Columbia, Missouri, USA
| | - Eric M Walters
- National Swine Resource and Research Center, University of Missouri, Columbia, Missouri, USA
| | - Clifton N Murphy
- National Swine Resource and Research Center, University of Missouri, Columbia, Missouri, USA
| | - Zoltan Machaty
- Department of Animal Sciences, Purdue University, West Lafayette, Indiana, USA
| | - Randall S Prather
- Division of Animal Science, University of Missouri, Columbia, Missouri, USA; National Swine Resource and Research Center, University of Missouri, Columbia, Missouri, USA
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98
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Involvement of mouse and porcine PLCζ-induced calcium oscillations in preimplantation development of mouse embryos. Biochem Biophys Res Commun 2015; 460:476-81. [DOI: 10.1016/j.bbrc.2015.03.058] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Accepted: 03/10/2015] [Indexed: 11/23/2022]
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99
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Kalo D, Roth Z. Effects of mono(2-ethylhexyl)phthalate on cytoplasmic maturation of oocytes--The bovine model. Reprod Toxicol 2015; 53:141-51. [PMID: 25900598 DOI: 10.1016/j.reprotox.2015.04.007] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 03/09/2015] [Accepted: 04/03/2015] [Indexed: 02/08/2023]
Abstract
Phthalates are known reproductive toxicants, but their intracellular disruptive effects on oocyte maturation competence are less known. We studied the potential risk associated with acute exposure of oocytes to mono(2-ethylhexyl)phthalate (MEHP). First, bovine oocytes were matured in vitro with or without 50 μM MEHP and examined for mitochondrial features associated with DNA fragmentation. MEHP increased reactive oxygen species levels and reduced the proportion of highly polarized mitochondria along with alterations in genes associated with mitochondrial oxidative phosphorylation (CYC1, MT-CO1 and ATP5B). In a second set of experiments, we associated the effects of MEHP on meiotic progression with those on cytoplasmic maturation. MEHP impaired reorganization of cytoplasmic organelles in matured oocytes reflected by reductions in category I mitochondria, type III cortical granules and class I endoplasmic reticulum. These alterations are associated with the previously reported reduced developmental competence of MEHP-treated bovine oocytes, and reveal the risk associated with acute exposure.
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Affiliation(s)
- D Kalo
- Department of Animal Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, and Center of Excellence in Agriculture and Environmental Health, the Hebrew University, Rehovot 76100, Israel
| | - Z Roth
- Department of Animal Sciences, Robert H. Smith Faculty of Agriculture, Food and Environment, and Center of Excellence in Agriculture and Environmental Health, the Hebrew University, Rehovot 76100, Israel.
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100
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Armant DR. Intracellular Ca2+ signaling and preimplantation development. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2015; 843:151-71. [PMID: 25956298 PMCID: PMC10412982 DOI: 10.1007/978-1-4939-2480-6_6] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The key, versatile role of intracellular Ca2+ signaling during egg activation after fertilization has been appreciated for several decades. More recently, evidence has accumulated supporting the concept that cytoplasmic Ca2+ is also a major signaling nexus during subsequent development of the fertilized ovum. This chapter will review the molecular reactions that regulate intracellular Ca2+ levels and cell function, the role of Ca2+ signaling during egg activation and specific examples of repetitive Ca2+ signaling found throughout pre- and peri-implantation development. Many of the upstream and downstream pathways utilized during egg activation are also critical for specific processes that take place during embryonic development. Much remains to be done to elucidate the full complexity of Ca2+ signaling mechanisms in preimplantation embryos to the level of detail accomplished for egg activation. However, an emerging concept is that because this second messenger can be modulated downstream of numerous receptors and is able to bind and activate multiple cytoplasmic signaling proteins, it can help the coordination of development through up- and downstream pathways that change with each embryonic stage.
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Affiliation(s)
- D Randall Armant
- Department of Obstetrics and Gynecology, Wayne State University C.S. Mott Center for Human Growth and Development, 275 E. Hancock Street, 48201-1405, Detroit, MI, USA,
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