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Wen J, Yao X, Lu R, Geng S, Wang J, Zhou J, Li Y, Hu L. Associations between seminal plasma metals/metalloids and semen quality: A cross-sectional study. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 279:116472. [PMID: 38761496 DOI: 10.1016/j.ecoenv.2024.116472] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 05/13/2024] [Accepted: 05/14/2024] [Indexed: 05/20/2024]
Abstract
Exposure to metals/metalloids is reported to potentially influence semen quality. While most studies have focused on single metal impacts, the link between exposure to multiple metals and semen quality has remained less explored. The study aimed to investigate the effects of both individual and mixed metal/metalloid exposure on semen quality. A total of 330 men were recruited from three reproductive centers in eastern China. Seminal plasma levels of 25 metals/metalloids and sperm parameters were determined. We used the Generalized Linear Model (GLM) and Restricted Cubic Spline (RCS) to assess the relationships between single metals/metalloids and semen quality. The weighted quantile sum (WQS) models were then applied to evaluate the combined effect of all these metals/metalloids. We observed positive associations of exposure to lithium (Li), zinc (Zn), and magnesium (Mg) with an increased risk of below reference values for progressive motility and total motility using a logistic regression model (P < 0.05). Additionally, our results also revealed a significant inverse relationship between aluminum (Al) and both sperm concentration and count, while cobalt (Co) demonstrated a positive association with sperm concentration (P < 0.05). Notably, the WQS model indicated a significant positive association between exposure to metal/metalloid mixtures and the risk of abnormal progressive motility (OR: 1.57; 95%CI: 1.10, 2.24) and abnormal total motility (OR: 1.53; 95%CI: 1.06, 2.19), with this association primarily driven by Li, Mg, and Zn. In summary, our findings indicate that exposure to metal/metalloid mixtures might have an adverse effect on semen quality.
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Affiliation(s)
- Juan Wen
- Nanjing Women and Children's Healthcare Institute, Women's Hospital of Nanjing Medical University, Nanjing Women and Children's Healthcare Hospital, Nanjing, Jiangsu 210000, China.
| | - Xiaodie Yao
- Nanjing Women and Children's Healthcare Institute, Women's Hospital of Nanjing Medical University, Nanjing Women and Children's Healthcare Hospital, Nanjing, Jiangsu 210000, China
| | - Renjie Lu
- Changzhou Third People's Hospital, Changzhou Medical Center, Nanjing Medical University, Changzhou, Jiangsu 213000, China
| | - Shijie Geng
- Nanjing Women and Children's Healthcare Institute, Women's Hospital of Nanjing Medical University, Nanjing Women and Children's Healthcare Hospital, Nanjing, Jiangsu 210000, China
| | - Junya Wang
- Nanjing Women and Children's Healthcare Institute, Women's Hospital of Nanjing Medical University, Nanjing Women and Children's Healthcare Hospital, Nanjing, Jiangsu 210000, China
| | - Jing Zhou
- Department of Reproduction, Changzhou Maternity and Child Health Care Hospital, Changzhou Medical Center, Nanjing Medical University, Changzhou, Jiangsu 213000, China
| | - Ying Li
- Department of Obstetrics and Gynecology, The Affiliated Wuxi People's Hospital of Nanjing Medical University, Wuxi, Jiangsu 214000, China
| | - Lingmin Hu
- Department of Reproduction, Changzhou Maternity and Child Health Care Hospital, Changzhou Medical Center, Nanjing Medical University, Changzhou, Jiangsu 213000, China.
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The Therapeutic and Diagnostic Potential of Phospholipase C Zeta, Oocyte Activation, and Calcium in Treating Human Infertility. Pharmaceuticals (Basel) 2023; 16:ph16030441. [PMID: 36986540 PMCID: PMC10056371 DOI: 10.3390/ph16030441] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 02/19/2023] [Accepted: 03/06/2023] [Indexed: 03/17/2023] Open
Abstract
Oocyte activation, a fundamental event during mammalian fertilisation, is initiated by concerted intracellular patterns of calcium (Ca2+) release, termed Ca2+ oscillations, predominantly driven by testis-specific phospholipase C zeta (PLCζ). Ca2+ exerts a pivotal role in not just regulating oocyte activation and driving fertilisation, but also in influencing the quality of embryogenesis. In humans, a failure of Ca2+ release, or defects in related mechanisms, have been reported to result in infertility. Furthermore, mutations in the PLCζ gene and abnormalities in sperm PLCζ protein and RNA, have been strongly associated with forms of male infertility where oocyte activation is deficient. Concurrently, specific patterns and profiles of PLCζ in human sperm have been linked to parameters of semen quality, suggesting the potential for PLCζ as a powerful target for both therapeutics and diagnostics of human fertility. However, further to PLCζ and given the strong role played by Ca2+ in fertilisation, targets down- and up-stream of this process may also present a significantly similar level of promise. Herein, we systematically summarise recent advancements and controversies in the field to update expanding clinical associations between Ca2+-release, PLCζ, oocyte activation and human fertility. We discuss how such associations may potentially underlie defective embryogenesis and recurrent implantation failure following fertility treatments, alongside potential diagnostic and therapeutic avenues presented by oocyte activation for the diagnosis and treatment of human infertility.
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Wang F, Fan LH, Li A, Dong F, Hou Y, Schatten H, Sun QY, Ou XH. Effects of various calcium transporters on mitochondrial Ca 2+ changes and oocyte maturation. J Cell Physiol 2021; 236:6548-6558. [PMID: 33704771 DOI: 10.1002/jcp.30327] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/22/2021] [Accepted: 02/04/2021] [Indexed: 11/10/2022]
Abstract
Ca2+ participates in many important cellular processes, but the underlying mechanisms are still poorly understood, especially during oocyte maturation. First, we confirmed that calcium in the culture medium was essential for oocyte maturation. Next, various inhibitors of Ca2+ channels were applied to investigate their roles in mitochondrial Ca2+ changes and oocyte maturation. Our results showed that Trmp7, Orai, T-type Ca2+ channels and Na+ /Ca2+ exchanger complex (NCLX) were important for oocyte maturation. Trmp7 inhibition delayed germinal vesicle breakdown. Orai and NCLX inhibition significantly weakened the distribution of mitochondrial Ca2+ around the nucleus compared to the Ctrl group. Interestingly, even T-type Ca2+ channels-specific inhibitor Mibefradil blocked germinal vesicle breakdown; mitochondrial Ca2+ surrounding the nucleus still was maintained at a high level without spindle formation. Two calcium transporter inhibitors, Thapsigargin and Ruthenium Red, which have been confirmed to inhibit oocyte activation, did not significantly affect oocyte maturation. Increasing the knowledge of calcium transport may provide a basis to build on for improving oocyte in vitro maturation in human assisted reproduction clinics.
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Affiliation(s)
- Feng Wang
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
- Bioland Laboratory (Guangzhou Regenerative Medicine and Health Guangdong Laboratory), Guangzhou, China
| | - Li-Hua Fan
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Ang Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Feng Dong
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Yi Hou
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Heide Schatten
- Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri, USA
| | - Qing-Yuan Sun
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Xiang-Hong Ou
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
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Shi X, Chan CPS, Man GKY, Chan DYL, Wong MH, Li TC. Associations between blood metal/ metalloid concentration and human semen quality and sperm function: A cross-sectional study in Hong Kong. J Trace Elem Med Biol 2021; 65:126735. [PMID: 33647736 DOI: 10.1016/j.jtemb.2021.126735] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 02/09/2021] [Accepted: 02/19/2021] [Indexed: 01/18/2023]
Abstract
BACKGROUND The association between metal/metalloid exposure on human sperm quality is still inconclusive. There is a lack of data on the effect of metal/metalloid on sperm function. METHODS The aim of this study was to clarify the association between blood metal/metalloid concentration and traditional and functional sperm parameters, the blood concentration of Pb, Hg, Cd, As, Ni, Mo, Zn, Cu, Se, Fe, Mg, Cr and Ca of 288 men in Hong Kong were assessed by inductively coupled plasma-mass spectrometry, and sperm parameters including sperm concentration, motility, morphology, vitality, total sperm count, total motile sperm count, sperm DNA fragmentation and sperm acrosome reaction were measured. Demographic and lifestyle questionnaires were also provided for all participants. Multivariable linear regression analysis was performed to test the association between blood metal/ metalloid concentration and semen parameters after adjusting for relevant confounding variables. RESULTS The results showed that moderate to high level of blood Pb concentration (>27.19 μg/L) appeared to be negatively associated with sperm morphology (P < 0.05); high level of blood Cd concentration (>1.44 μg/L) was negatively associated with sperm acrosome reaction (P < 0.05); Mo was positively associated with semen volume (P < 0.05), however, high level of blood Mo concentration (>13.52 μg/L) was negatively associated with sperm vitality (P < 0.05); high level of blood Zn concentration (>6.20 mg/L) was positively associated with sperm vitality (P < 0.05); moderate level of blood Fe concentration (526.89-566.63 mg/L) was positively associated with sperm acrosome reaction (P < 0.05); moderate level of blood Ca concentration (55.92-66.10 mg/L) was positively associated with semen volume (P < 0.05); however, lower level of blood Ca concentration (45.90-55.92 mg/L) was negatively associated with sperm morphology (P < 0.05). CONCLUSIONS Our results suggested that the sperm function could be affected by blood Cd and Fe concentration and traditional sperm parameters could be affected by blood concentration of Mo, Zn, Pb and Ca.
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Affiliation(s)
- Xiao Shi
- Assisted Conception Unit, Department of Obstetrics and Gynaecology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, People's Republic of China; Center for Reproductive Medicine, Department of Obstetrics and Gynaecology, Nanfang Hospital, Southern Medical University, People's Republic of China
| | - Carol Pui Shan Chan
- Assisted Conception Unit, Department of Obstetrics and Gynaecology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Grace Ka Yan Man
- Consortium on Health, Environment, Education and Research (CHEER), Department of Science and Environmental Studies, The Education University of Hong Kong, Hong Kong, People's Republic of China
| | - David Yiu Leung Chan
- Assisted Conception Unit, Department of Obstetrics and Gynaecology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, People's Republic of China
| | - Ming Hung Wong
- Consortium on Health, Environment, Education and Research (CHEER), Department of Science and Environmental Studies, The Education University of Hong Kong, Hong Kong, People's Republic of China; School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, People's Republic of China.
| | - Tin-Chiu Li
- Assisted Conception Unit, Department of Obstetrics and Gynaecology, Prince of Wales Hospital, The Chinese University of Hong Kong, Hong Kong, People's Republic of China.
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Effects of Premating Calcium and Phosphorus Supplementation on Reproduction Efficiency of Grazing Yak Heifers. Animals (Basel) 2021; 11:ani11020554. [PMID: 33672512 PMCID: PMC7923756 DOI: 10.3390/ani11020554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2021] [Revised: 02/07/2021] [Accepted: 02/16/2021] [Indexed: 11/16/2022] Open
Abstract
Simple Summary This study was realized to explore the effects of calcium chloride (CaCl) and monocalcium phosphate (MCP) supplementation on the reproductive efficiency of grazing yak heifers. The body weight, serum markers of bone metabolism, and conception and calving rate of grazing yaks in control group and supplementary feeding groups were compared. The results revealed that supplementation with MCP but not CaCl could significantly improve the reproductive performance, possibly due to the improvement in body weight and bone phosphorus storage providing better estrous physiological conditions for grazing yak heifers. The findings of this study may be helpful and instructional to improve the reproductive efficiency of yaks on the Qinghai Tibet Plateau. Abstract Reproductive efficiency is the main factor limiting yak production on the Tibet Plateau. The purpose of this study was to investigate the effect of supplementation with calcium chloride (CaCl) and monocalcium phosphate (MCP) for 30 days before breeding on body weight (BW) change, serum bone metabolism biomarkers, conception rate, and calving rate of grazing yaks. Ninety 3 year old yak heifers (153.05 ± 6.56 kg BW) were assigned to three treatments (n = 30 per treatment): grazing without supplementation (CONT), grazing plus calcium chloride supplementation (CaCl), and grazing plus monocalcium phosphate supplementation (MCP). Compared with the CONT group, supplementation with CaCl increased the serum concentrations of osteocalcin and decreased the alkaline phosphatase (ALP) levels (p < 0.05); supplementation with MCP increased the average daily gain (ADG), serum concentrations of phosphorus (P) and osteocalcin, conception rate, and calving rate (p < 0.05), whereas it decreased the serum concentrations of hydroxyproline, ALP, and calcitonin (p < 0.05). Both CaCl and MCP supplementation had no effect on serum calcium (Ca) concentration. The ADG, conception rate, and calving rate were higher in the MCP group than in the CaCl group (p < 0.05), while the serum concentrations of hydroxyproline and calcitonin were lower (p < 0.05). It could be concluded that premating supplementation with MCP increased the body weight gain and subsequent conception and calving rate of grazing yaks. Supplementation with MCP had a positive effect on body condition and bone metabolism, thus providing a better estrous condition for grazing yak heifers, which could contribute to enhancing reproduction efficiency.
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Wang F, Li A, Meng TG, Wang LY, Wang LJ, Hou Y, Schatten H, Sun QY, Ou XH. Regulation of [Ca 2+] i oscillations and mitochondrial activity by various calcium transporters in mouse oocytes. Reprod Biol Endocrinol 2020; 18:87. [PMID: 32799904 PMCID: PMC7429721 DOI: 10.1186/s12958-020-00643-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 08/10/2020] [Indexed: 12/12/2022] Open
Abstract
Oocyte activation inefficiency is one of the reasons for female infertility and Ca2+ functions play a critical role in the regulation of oocyte activation. We used various inhibitors of Ca2+ channels located on the membrane, including sarcoplasmic/ endoplasmic reticulum Ca2+ATPases (SERCAs, the main Ca2+ pumps which decrease the intracellular Ca2+ level by refilling Ca2+ into the sarcoplasmic reticulum), transient receptor potential (TRP) ion channel subfamily member 7 (TRPM7, a Ca2+/Mg2+-permeable non-selective cation channel), T-type Ca2+ channels and calcium channel Orai1, to investigate their roles in [Ca2+]i oscillation patterns and mitochondrial membrane potential during oocyte activation by real-time recording. Our results showed that SERCAs, TRPM7 and T-type Ca2+ channels were important for initiation and maintenance of [Ca2+]i oscillations, which was required for mitochondrial membrane potential elevation during oocyte activation, as well as oocyte cytoskeleton stability and subsequent embryo development. Increasing the knowledge of calcium transport may provide a theoretical basis for improving oocyte activation in human assisted reproduction clinics.
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Affiliation(s)
- Feng Wang
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, 510317 China
- grid.9227.e0000000119573309China State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Ang Li
- grid.9227.e0000000119573309China State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Tie-Gang Meng
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, 510317 China
- grid.9227.e0000000119573309China State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Le-Yun Wang
- grid.9227.e0000000119573309China State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Li-Juan Wang
- grid.9227.e0000000119573309China State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Yi Hou
- grid.9227.e0000000119573309China State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Heide Schatten
- grid.134936.a0000 0001 2162 3504Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211 USA
| | - Qing-Yuan Sun
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, 510317 China
- grid.9227.e0000000119573309China State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101 China
| | - Xiang-Hong Ou
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, 510317 China
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Wang F, Li A, Li QN, Fan LH, Wang ZB, Meng TG, Hou Y, Schatten H, Sun QY, Ou XH. Effects of mitochondria-associated Ca 2+ transporters suppression on oocyte activation. Cell Biochem Funct 2020; 39:248-257. [PMID: 32643225 DOI: 10.1002/cbf.3571] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 06/05/2020] [Accepted: 06/07/2020] [Indexed: 12/14/2022]
Abstract
Oocyte activation deficiency leads to female infertility. [Ca2+ ]i oscillations are required for mitochondrial energy supplement transition from the resting to the excited state, but the underlying mechanisms are still very little known. Three mitochondrial Ca2+ channels, Mitochondria Calcium Uniporter (MCU), Na+ /Ca2+ Exchanger (NCLX) and Voltage-dependent Ca2+ Channel (VDAC), were deactivated by inhibitors RU360, CGP37157 and Erastin, respectively. Both Erastin and CGP37157 inhibited mitochondrial activity significantly while attenuating [Ca2+ ]i and [Ca2+ ]m oscillations, which caused developmental block of pronuclear formation. Thus, NCLX and VDAC are two mitochondria-associated Ca2+ transporter proteins regulating oocyte activation, which may be used as potential targets to treat female infertility. SIGNIFICANCE OF THE STUDY: NCLX and VDAC are two mitochondria-associated Ca2+ transporter proteins regulating oocyte activation.
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Affiliation(s)
- Feng Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Ang Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Qian-Nan Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Li-Hua Fan
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Zhen-Bo Wang
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Tie-Gang Meng
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Yi Hou
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
| | - Heide Schatten
- Department of Veterinary Pathobiology, University of Missouri, Columbia, Missouri, USA
| | - Qing-Yuan Sun
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.,Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
| | - Xiang-Hong Ou
- Fertility Preservation Lab, Reproductive Medicine Center, Guangdong Second Provincial General Hospital, Guangzhou, China
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Liu C, Liu H, Luo Y, Lu T, Fu X, Cui S, Zhu S, Hou Y. The extracellular calcium-sensing receptor promotes porcine egg activation via calcium/calmodulin-dependent protein kinase II. Mol Reprod Dev 2020; 87:598-606. [PMID: 32017318 DOI: 10.1002/mrd.23322] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Accepted: 12/27/2019] [Indexed: 12/24/2022]
Abstract
Extracellular calcium is required for intracellular Ca2+ oscillations needed for egg activation, but the regulatory mechanism is still poorly understood. The present study was designed to demonstrate the function of calcium-sensing receptor (CASR), which could recognize extracellular calcium as first messenger, during porcine egg activation. CASR expression was markedly upregulated following egg activation. Functionally, the addition of CASR agonist NPS R-568 significantly enhanced pronuclear formation rate, while supplementation of CASR antagonist NPS2390 compromised egg activation. There was no change in NPS R-568 group compared with control group when the egg activation was performed without extracellular calcium addition. The addition of NPS2390 precluded the activation-dependent [Ca2+ ]i rise. When egg activation was conducted in intracellular Ca2+ chelator BAPTA-AM and NPS R-568 containing medium, CASR function was abolished. Meanwhile, CASR activation increased the level of the [Ca2+ ]i effector p-CAMKII, and the presence of KN-93, an inhibitor of CAMKII, significantly reduced the CASR-mediated increasement of pronuclear formation rate. Furthermore, the increase of CASR expression following activation was reversed by inhibiting CAMKII activity, supporting a positive feedback loop between CAMKII and CASR. Altogether, these findings provide a new pathway of egg activation about CASR, as the extracellular Ca2+ effector, promotes egg activation via its downstream effector and upstream regulator CAMKII.
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Affiliation(s)
- Cong Liu
- School of Basic Medical Science, Wuhan University, Wuhan, China
| | - Huage Liu
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Yan Luo
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Tengfei Lu
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xiangwei Fu
- Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Sheng Cui
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
| | - Shien Zhu
- Key Laboratory of Animal Genetics, Breeding and Reproduction, Ministry of Agriculture and National Engineering Laboratory for Animal Breeding, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Yunpeng Hou
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences, China Agricultural University, Beijing, China
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Reyes JM, Silva E, Chitwood JL, Schoolcraft WB, Krisher RL, Ross PJ. Differing molecular response of young and advanced maternal age human oocytes to IVM. Hum Reprod 2018; 32:2199-2208. [PMID: 29025019 DOI: 10.1093/humrep/dex284] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Accepted: 08/22/2017] [Indexed: 12/11/2022] Open
Abstract
STUDY QUESTION What effect does maternal age have on the human oocyte's molecular response to in vitro oocyte maturation? SUMMARY ANSWER Although polyadenylated transcript abundance is similar between young and advanced maternal age (AMA) germinal vesicle (GV) oocytes, metaphase II (MII) oocytes exhibit a divergent transcriptome resulting from a differential response to in vitro oocyte maturation. WHAT IS KNOWN ALREADY Microarray studies considering maternal age or maturation stage have shown that either of these factors will affect oocyte polyadenylated transcript abundance in human oocytes. However, studies considering both human oocyte age and multiple stages simultaneously are limited to a single study that examined transcript levels for two genes by qPCR. Thus, polyadenylated RNA sequencing (RNA-Seq) could provide novel insight into age-associated aberrations in gene expression in GV and MII oocytes. STUDY DESIGN, SIZE, DURATION The effect of maternal age (longitudinal analysis) on polyadenylated transcript abundance at different stages was analyzed by examining single GV and single in vitro matured MII oocytes derived from five young (YNG; < 30 years; average age 26.8; range 20-29) and five advanced maternal age (AMA; ≥40 years; average age 41.6 years; range 40-43 years) patients. Thus, a total of 10 YNG (5 GV and 5 MII) and 10 AMA (5 GV and 5 MII) oocytes were individually processed for RNA-Seq analysis. PARTICIPANTS/MATERIALS, SETTINGS, METHODS Patients undergoing infertility treatment at the Colorado Center for Reproductive Medicine (Lone Tree, CO, USA) underwent ovarian stimulation with FSH and received hCG for final follicular maturation prior to ultrasound guided oocyte retrieval. Unused GV oocytes obtained at retrieval were donated for transcriptome analysis. Single oocytes were stored (at -80°C in PicoPure RNA Extraction Buffer; Thermo Fisher Scientific, USA) immediately upon verification of immaturity or after undergoing in vitro oocyte maturation (24 h incubation), representing GV and MII samples, respectively. After isolating RNA and generating single oocyte RNA-Seq libraries (SMARTer Ultra Low Input RNA HV kit; Clontech, USA), Illumina sequencing (100 bp paired-end reads on HiSeq 2500) and bioinformatics analysis (CLC Genomics Workbench, DESeq2, weighted gene correlation network analysis (WGCNA), Ingenuity Pathway Analysis) were performed. MAIN RESULTS AND THE ROLE OF CHANCE A total of 12 770 genes were determined to be expressed in human oocytes (reads per kilobase per million mapped reads (RPKM) > 0.4 in at least three of five replicates for a minimum of one sample type). Differential gene expression analysis between YNG and AMA oocytes (within stage) identified 1 and 255 genes that significantly differed (adjusted P < 0.1 and log2 fold change >1) in polyadenylated transcript abundance for GV and MII oocytes, respectively. These genes included CDK1, NLRP5 and PRDX1, which have been reported to affect oocyte developmental potential. Despite the similarity in transcript abundance between GV oocytes irrespective of age, divergent expression patterns emerged during oocyte maturation. These age-specific differentially expressed genes were enriched (FDR < 0.05) for functions and pathways associated with mitochondria, cell cycle and cytoskeleton. Gene modules generated by WGCNA (based on gene expression) and patient traits related to oocyte quality (e.g. age and blastocyst development) were correlated (P < 0.05) and enriched (FDR < 0.05) for functions and pathways associated with oocyte maturation. LARGE SCALE DATA Raw data from this study can be accessed through GSE95477. LIMITATIONS, REASONS FOR CAUTION The human oocytes used in the current study were obtained from patients with varying causes of infertility (e.g. decreased oocyte quality and oocyte quality-independent factors), possibly affecting oocyte gene expression. Oocytes in this study were retrieved at the GV stage following hCG administration and the MII oocytes were derived by IVM of patient oocytes. Although the approach has the benefit of identifying intrinsic differences between samples, it may not be completely representative of in vivo matured oocytes. WIDER IMPLICATIONS OF THE FINDINGS Transcriptome profiles of YNG and AMA oocytes, particularly at the MII stage, suggest that aberrant transcript abundance may contribute to the age-associated decline in fertility. STUDY FUNDING/COMPETING INTEREST(S) J.M.R. was supported by an Austin Eugene Lyons Fellowship awarded by the University of California, Davis. The Eunice Kennedy Shriver National Institute of Child Health and Human Development of the National Institutes of Health (awarded to P.J.R.; R01HD070044) and the Fertility Laboratories of Colorado partly supported the research presented in this manuscript.
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Affiliation(s)
- J M Reyes
- Department of Animal Science, University of California Davis, One Shields Avenue, Davis, CA 95616, USA
| | - E Silva
- Colorado Center for Reproductive Medicine, 10290 Ridgegate Circle, Lone Tree, CO 80124, USA
| | - J L Chitwood
- Department of Animal Science, University of California Davis, One Shields Avenue, Davis, CA 95616, USA
| | - W B Schoolcraft
- Colorado Center for Reproductive Medicine, 10290 Ridgegate Circle, Lone Tree, CO 80124, USA
| | - R L Krisher
- Colorado Center for Reproductive Medicine, 10290 Ridgegate Circle, Lone Tree, CO 80124, USA
| | - P J Ross
- Department of Animal Science, University of California Davis, One Shields Avenue, Davis, CA 95616, USA
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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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11
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Optimum calcium concentration: a crucial factor in regulating sperm motility in vitro. Cell Biochem Biophys 2015; 70:1177-83. [PMID: 24880438 DOI: 10.1007/s12013-014-0038-x] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Sperm motility can be maintained in vitro by incubation in a defined medium under specific conditions. In most studies, the exact role of various constituents of epididymal fluid, including calcium, has remained obscure. Most of the culture media have included millimolar concentrations of calcium, but previous reports have indicated that millimolar calcium inhibits sperm motility. In this present study, we sought the optimum concentration of extracellular calcium required for optimum sperm motility. This study showed that extracellular calcium has a concentration-dependent biphasic role in motility regulation. It promoted motility and velocity at lower (10 µM) concentration whereas notably inhibited it at higher concentrations. When external membrane-bound calcium was removed by ethylene glycol tetraacetic acid, motility decreased considerably. To confirm the motility-inhibiting role of calcium above 10 µM, a sperm motility-stimulating protein (MSP) recently reported from our laboratory was used which at 0.9 μM induces motility in 60-70 % cells. Calcium at 10 µM had no appreciable effect on the motility-promoting activity of the MSP but depressed the activity above 10 µM. Thus, our present results emphasize the biphasic role of extracellular calcium and the importance of its optimum concentration in different buffers and media used for sperm motility initiation.
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12
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Nomikos M, Sanders JR, Theodoridou M, Kashir J, Matthews E, Nounesis G, Lai FA, Swann K. Sperm-specific post-acrosomal WW-domain binding protein (PAWP) does not cause Ca2+ release in mouse oocytes. Mol Hum Reprod 2014; 20:938-47. [PMID: 25057041 DOI: 10.1093/molehr/gau056] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Mature mammalian oocytes undergo a prolonged series of cytoplasmic calcium (Ca(2+)) oscillations at fertilization that are the cause of oocyte activation. The Ca(2+) oscillations in mammalian oocytes are driven via inositol 1,4,5-trisphosphate (IP3) generation. Microinjection of the sperm-derived phospholipase C-zeta (PLCζ), which generates IP3, causes the same pattern of Ca(2+) oscillations as observed at mammalian fertilization and it is thought to be the physiological agent that triggers oocyte activation. However, another sperm-specific protein, 'post-acrosomal WW-domain binding protein' (PAWP), has also been reported to elicit activation when injected into mammalian oocytes, and to produce a Ca(2+) increase in frog oocytes. Here we have investigated whether PAWP can induce fertilization-like Ca(2+) oscillations in mouse oocytes. Recombinant mouse PAWP protein was found to be unable to hydrolyse phosphatidylinositol 4,5-bisphosphate in vitro and did not cause any detectable Ca(2+) release when microinjected into mouse oocytes. Microinjection with cRNA encoding either the untagged PAWP, or yellow fluorescent protein (YFP)-PAWP, or luciferase-PAWP fusion proteins all failed to trigger Ca(2+) increases in mouse oocytes. The lack of response in mouse oocytes was despite PAWP being robustly expressed at similar or higher concentrations than PLCζ, which successfully initiated Ca(2+) oscillations in every parallel control experiment. These data suggest that sperm-derived PAWP is not involved in triggering Ca(2+) oscillations at fertilization in mammalian oocytes.
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Affiliation(s)
- Michail Nomikos
- Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - Jessica R Sanders
- Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - Maria Theodoridou
- Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK National Center for Scientific Research 'Demokritos', 15310 Aghia Paraskevi, Greece
| | - Junaid Kashir
- Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - Emily Matthews
- Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - George Nounesis
- National Center for Scientific Research 'Demokritos', 15310 Aghia Paraskevi, Greece
| | - F Anthony Lai
- Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
| | - Karl Swann
- Institute of Molecular and Experimental Medicine, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XN, UK
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Chen Y, Kong S, Tang X, Fu Y, Wang B, Zhang S, Wang H. Preimplantation Mouse Embryo Is a Target for Opioid Ligand-Receptor Signaling1. Biol Reprod 2014; 91:4. [DOI: 10.1095/biolreprod.114.118083] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
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14
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Gonzalez-Garcia JR, Bradley J, Nomikos M, Paul L, Machaty Z, Lai FA, Swann K. The dynamics of MAPK inactivation at fertilization in mouse eggs. J Cell Sci 2014; 127:2749-60. [PMID: 24741069 PMCID: PMC4058113 DOI: 10.1242/jcs.145045] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Egg activation at fertilization in mammals is initiated by prolonged Ca(2+) oscillations that trigger the completion of meiosis and formation of pronuclei. A fall in mitogen-activated protein kinase (MAPK) activity is essential for pronuclear formation, but the precise timing and mechanism of decline are unknown. Here, we have measured the dynamics of MAPK pathway inactivation during fertilization of mouse eggs using novel chemiluminescent MAPK activity reporters. This reveals that the MAPK activity decrease begins during the Ca(2+) oscillations, but MAPK does not completely inactivate until after pronuclear formation. The MAPKs present in eggs are Mos, MAP2K1 and MAP2K2 (MEK1 and MEK2, respectively) and MAPK3 and MAPK1 (ERK1 and ERK2, respectively). Notably, the MAPK activity decline at fertilization is not explained by upstream destruction of Mos, because a decrease in the signal from a Mos-luciferase reporter is not associated with egg activation. Furthermore, Mos overexpression does not affect the timing of MAPK inactivation or pronuclear formation. However, the late decrease in MAPK could be rapidly reversed by the protein phosphatase inhibitor, okadaic acid. These data suggest that the completion of meiosis in mouse zygotes is driven by an increased phosphatase activity and not by a decline in Mos levels or MEK activity.
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Affiliation(s)
- Jose Raul Gonzalez-Garcia
- Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK
| | - Josephine Bradley
- Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - Michail Nomikos
- Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK
| | - Laboni Paul
- Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK School of Biosciences, Cardiff University, Cardiff CF10 3AX, UK
| | - Zoltan Machaty
- Department of Animal Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - F Anthony Lai
- Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK
| | - Karl Swann
- Institute of Molecular and Experimental Medicine, School of Medicine, Cardiff University, Cardiff CF14 4XN, UK
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15
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Buschiazzo J, Ialy-Radio C, Auer J, Wolf JP, Serres C, Lefèvre B, Ziyyat A. Cholesterol depletion disorganizes oocyte membrane rafts altering mouse fertilization. PLoS One 2013; 8:e62919. [PMID: 23638166 PMCID: PMC3636221 DOI: 10.1371/journal.pone.0062919] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2012] [Accepted: 03/29/2013] [Indexed: 11/18/2022] Open
Abstract
Drastic membrane reorganization occurs when mammalian sperm binds to and fuses with the oocyte membrane. Two oocyte protein families are essential for fertilization, tetraspanins and glycosylphosphatidylinositol-anchored proteins. The firsts are associated to tetraspanin-enriched microdomains and the seconds to lipid rafts. Here we report membrane raft involvement in mouse fertilization assessed by cholesterol modulation using methyl-β-cyclodextrin. Cholesterol removal induced: (1) a decrease of the fertilization rate and index; and (2) a delay in the extrusion of the second polar body. Cholesterol repletion recovered the fertilization ability of cholesterol-depleted oocytes, indicating reversibility of these effects. In vivo time-lapse analyses using fluorescent cholesterol permitted to identify the time-point at which the probe is mainly located at the plasma membrane enabling the estimation of the extent of the cholesterol depletion. We confirmed that the mouse oocyte is rich in rafts according to the presence of the raft marker lipid, ganglioside GM1 on the membrane of living oocytes and we identified the coexistence of two types of microdomains, planar rafts and caveolae-like structures, by terms of two differential rafts markers, flotillin-2 and caveolin-1, respectively. Moreover, this is the first report that shows characteristic caveolae-like invaginations in the mouse oocyte identified by electron microscopy. Raft disruption by cholesterol depletion disturbed the subcellular localization of the signal molecule c-Src and the inhibition of Src kinase proteins prevented second polar body extrusion, consistent with a role of Src-related kinases in fertilization via signaling complexes. Our data highlight the functional importance of intact membrane rafts for mouse fertilization and its dependence on cholesterol.
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Affiliation(s)
- Jorgelina Buschiazzo
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques, F75014 Paris, France
- Instituto de Investigaciones Bioquímicas de Bahía Blanca (UNS-CONICET), Bahía Blanca, Argentina
| | - Come Ialy-Radio
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques, F75014 Paris, France
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques. F75014 Paris, France
| | - Jana Auer
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques, F75014 Paris, France
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques. F75014 Paris, France
| | - Jean-Philippe Wolf
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques, F75014 Paris, France
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques. F75014 Paris, France
- Service d’Histologie Embryologie Biologie de la Reproduction Hôpital Cochin, AP-HP, F75014 Paris, France
| | - Catherine Serres
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques, F75014 Paris, France
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques. F75014 Paris, France
| | - Brigitte Lefèvre
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques, F75014 Paris, France
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques. F75014 Paris, France
| | - Ahmed Ziyyat
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques, F75014 Paris, France
- INSERM U1016, Institut Cochin, Université Paris Descartes, 24 rue du Faubourg Saint-Jacques. F75014 Paris, France
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McGinnis LK, Luo J, Kinsey WH. Protein tyrosine kinase signaling in the mouse oocyte cortex during sperm-egg interactions and anaphase resumption. Mol Reprod Dev 2013; 80:260-72. [PMID: 23401167 DOI: 10.1002/mrd.22160] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 02/01/2013] [Indexed: 02/06/2023]
Abstract
Fertilization triggers activation of a series of pre-programmed signal transduction pathways in the oocyte that establish a block to polyspermy, induce meiotic resumption, and initiate zygotic development. Fusion between sperm and oocyte results in rapid changes in oocyte intracellular free-calcium levels, which in turn activate multiple protein kinase cascades in the ooplasm. The present study examined the possibility that sperm-oocyte interaction involves localized activation of oocyte protein tyrosine kinases, which could provide an alternative signaling mechanism to that triggered by the fertilizing sperm. Confocal immunofluorescence analysis with antibodies to phosphotyrosine and phosphorylated protein tyrosine kinases allowed detection of minute signaling events localized to the site of sperm-oocyte interaction that were not amenable to biochemical analysis. The results provide evidence for localized accumulation of phosphotyrosine at the site of sperm contact, binding, or fusion, which suggests active protein tyrosine kinase signaling prior to and during sperm incorporation. The PYK2 kinase was found to be concentrated and activated at the site of sperm-oocyte interaction, and likely participates in this response. Widespread activation of PYK2 and FAK kinases was subsequently observed within the oocyte cortex, indicating that sperm incorporation is followed by more global signaling via these kinases during meiotic resumption. The results demonstrate an alternate signaling pathway triggered in mammalian oocytes by sperm contact, binding, or fusion with the oocyte.
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Affiliation(s)
- Lynda K McGinnis
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, Kansas 66160, USA
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17
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Kinsey WH. Intersecting roles of protein tyrosine kinase and calcium signaling during fertilization. Cell Calcium 2012. [PMID: 23201334 DOI: 10.1016/j.ceca.2012.11.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The oocyte is a highly specialized cell that must respond to fertilization with a preprogrammed series of signal transduction events that establish a block to polyspermy, trigger resumption of the cell cycle and execution of a developmental program. The fertilization-induced calcium transient is a key signal that initiates the process of oocyte activation and studies over the last several years have examined the signaling pathways that act upstream and downstream of this calcium transient. Protein tyrosine kinase signaling was found to be an important component of the upstream pathways that stimulated calcium release at fertilization in oocytes from animals that fertilize externally, but a similar pathway has not been found in mammals which fertilize internally. The following review will examine the diversity of signaling in oocytes from marine invertebrates, amphibians, fish and mammals in an attempt to understand the basis for the observed differences. In addition to the pathways upstream of the fertilization-induced calcium transient, recent studies are beginning to unravel the role of protein tyrosine kinase signaling downstream of the calcium transient. The PYK2 kinase was found to respond to fertilization in the zebrafish system and seems to represent a novel component of the response of the oocyte to fertilization. The potential impact of impaired PTK signaling in oocyte quality will also be discussed.
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Affiliation(s)
- William H Kinsey
- Department of Anatomy and Cell Biology, University of Kansas Medical Center, Kansas City, KS 66160, United States.
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18
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Bedford-Guaus SJ, McPartlin LA, Varner DD. Characterization of Equine Phospholipase C Zeta: A Review and Preliminary Results on Expression Defects in Subfertile Stallions. J Equine Vet Sci 2012. [DOI: 10.1016/j.jevs.2012.06.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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19
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Calcium Oscillations, Oocyte Activation, and Phospholipase C zeta. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 740:1095-121. [DOI: 10.1007/978-94-007-2888-2_50] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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20
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Martín-Romero FJ, López-Guerrero AM, Álvarez IS, Pozo-Guisado E. Role of Store-Operated Calcium Entry During Meiotic Progression and Fertilization of Mammalian Oocytes. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2012; 295:291-328. [DOI: 10.1016/b978-0-12-394306-4.00014-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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21
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Liang SL, Zhao QJ, Li XC, Jin YP, Wang YP, Su XH, Guan WJ, Ma YH. Dynamic analysis of Ca²+ level during bovine oocytes maturation and early embryonic development. J Vet Sci 2011; 12:133-42. [PMID: 21586872 PMCID: PMC3104167 DOI: 10.4142/jvs.2011.12.2.133] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Mammalian oocyte maturation and early embryo development processes are Ca2+-dependent. In this study, we used confocal microscopy to investigate the distribution pattern of Ca2+ and its dynamic changes in the processes of bovine oocytes maturation, in vitro fertilization (IVF), parthenogenetic activation (PA) and somatic cell nuclear transfer (SCNT) embryo development. During the germinal vesicle (GV) and GV breakdown stage, Ca2+ was distributed in the cortical ooplasm and throughout the oocytes from the MI to MII stage. In IVF embryos, Ca2+ was distributed in the cortical ooplasm before the formation of the pronucleus. In 4-8 cell embryos and morulas, Ca2+ was present throughout the blastomere. In PA embryos, Ca2+ was distributed throughout the blastomere at 48 h, similar to in the 4-cell and 8-cell phase and the morula. At 6 h after activation, there was almost no distribution of Ca2+ in the SCNT embryos. However, Ca2+ was distributed in the donor nucleus at 10 h and it was distributed throughout the blastomere in the 2-8 cell embryos. In this study, Ca2+ showed significant fluctuations with regularity of IVF and SCNT groups, but PA did not. Systematic investigation of the Ca2+ location and distribution changes during oocyte maturation and early embryo development processes should facilitate a better understanding of the mechanisms involved in oocyte maturation, reconstructed embryo activation and development, ultimately improving the reconstructed embryo development rate.
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Affiliation(s)
- Su Li Liang
- College of Veterinary Medicine, Northwest Agriculture and Forestry University, Yangling 712100, China
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22
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Hsu CC, Lin EC, Chen SC, Huang SC, Liu BH, Yu YH, Chen CC, Yang CC, Lien CY, Wang YH, Liu CW, Mersmann HJ, Cheng WTK, Ding ST. Differential gene expression between the porcine morula and blastocyst. Reprod Domest Anim 2011; 47:69-81. [PMID: 21599764 DOI: 10.1111/j.1439-0531.2011.01803.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The survival and development of pre-implantation embryos are determinant factors affecting the outcome of animal reproduction. It is essential to transfer the expression of the genetic material from maternal sources, that is the ovum to the zygote before implantation to ensure successful development. Differentiation and transformation of blastomeres initiated during the morula and blastocyst stages is an important step of the embryonic development prior to implantation. We collected morula and early blastocyst samples from pure-bred Landrace pigs in vivo to study the differential gene expression patterns at these two stages. Total RNA was extracted from individual embryos and two rounds of amplification were employed. Two micrograms of antisense RNA, targets, were prepared and hybridized with each of four custom made oligo microarrays representing 24,000 porcine genes. The analyses of replicate hybridizations showed that among the 24,000 genes, 162 genes were expressed fivefold or greater in the morula compared to early blastocysts and 2126 genes were expressed fivefold or greater in early blastocysts compared to the morula. Of these differentially expressed genes, 1429 genes were functionally annotated with related human Gene Ontology terms. In addition to basic metabolic processes, genes related to signal transduction, transportation and cell differentiation were found in both stages and were up-regulated as embryo development proceeded. Real time polymerase chain reaction was utilized to quantify 12 genes differentially expressed in the 2 embryonic stages and validated the reliability of major evidences shown in microarrays. In conclusion, we have obtained a preliminary landscape of genes differentially expressed during the transition from morula to early blastocysts in pigs and showed a generally increased transcriptional activity, perhaps in preparation for implantation. Our results provide an opportunity to study the functions of these genes in relation to the development and survival of pre-implantation porcine embryos.
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Affiliation(s)
- C C Hsu
- Department of Animal Science and Technology, Institute of Biotechnology, National Taiwan University, Taipei, Taiwan
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Derivation and long-term culture of human parthenogenetic embryonic stem cells using human foreskin feeders. J Assist Reprod Genet 2010; 27:285-91. [PMID: 20393797 DOI: 10.1007/s10815-010-9408-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2009] [Accepted: 03/11/2010] [Indexed: 12/28/2022] Open
Abstract
PURPOSE Feeder cells from animals raise considerable concern for contamination because they are directly in contact with embryonic stem cells. METHODS To address this issue we collected discarded foreskin tissue and prepared a fibroblast cell line. We transferred one parthenogenetic blastocyst on to these feeder cells, and later observed outgrowth. By this approach, we were able to derive a human parthenogenetic embryonic stem cell line successfully. RESULTS The embryonic stem cells had normal morphology, expressed all expected cell surface markers, could differentiate to embryonic bodies upon culture in vitro, and differentiated further to derivatives of all three germ layers. CONCLUSION This study indicates that homologous human fibroblasts can be used as feeder cells to support not only the propagation, but also the derivation of ES cells, and this should facilitate studies of therapeutic cloning for research and clinical applications.
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Luo J, McGinnis LK, Kinsey WH. Role of Fyn kinase in oocyte developmental potential. Reprod Fertil Dev 2010; 22:966-76. [PMID: 20591331 DOI: 10.1071/rd09311] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2009] [Accepted: 01/20/2010] [Indexed: 12/22/2022] Open
Abstract
Fyn kinase is highly expressed in oocytes, with inhibitor and dominant-negative studies suggesting a role in the signal transduction events during egg activation. The purpose of the present investigation was to test the hypothesis that Fyn is required for calcium signalling, meiosis resumption and pronuclear congression using the Fyn-knockout mouse as a model. Accelerated breeding studies revealed that Fyn-null females produced smaller litter sizes at longer intervals and exhibited a rapid decline in pup production with increasing age. Fyn-null females produced a similar number of oocytes, but the frequency of immature oocytes and mature oocytes with spindle chromosome abnormalities was significantly higher than in controls. Fertilised Fyn-null oocytes frequently (24%) failed to undergo pronuclear congression and remained at the one-cell stage. Stimulation with gonadotropins increased the number of oocytes ovulated, but did not overcome the above defects. Fyn-null oocytes overexpressed Yes kinase in an apparent effort to compensate for the loss of Fyn, yet still exhibited an altered pattern of protein tyrosine phosphorylation. In summary, Fyn-null female mice exhibit reduced fertility that appears to result from actin cytoskeletal defects rather than calcium signalling. These defects cause developmental arrest during oocyte maturation and pronuclear congression.
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Affiliation(s)
- Jinping Luo
- Center for Reproductive Sciences, University of Kansas Medical Center, Kansas City, KS 66160, USA
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Kashir J, Heindryckx B, Jones C, De Sutter P, Parrington J, Coward K. Oocyte activation, phospholipase C zeta and human infertility. Hum Reprod Update 2010; 16:690-703. [PMID: 20573804 DOI: 10.1093/humupd/dmq018] [Citation(s) in RCA: 167] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Mammalian oocytes are activated by intracellular calcium (Ca(2+)) oscillations following gamete fusion. Recent evidence implicates a sperm-specific phospholipase C zeta, PLCζ, which is introduced into the oocyte following membrane fusion, as the responsible factor. This review summarizes the current understanding of human oocyte activation failure and describes recent discoveries linking certain cases of male infertility with defects in PLCζ expression and activity. How these latest findings may influence future diagnosis and treatment options are also discussed. METHODS Systematic literature searches were performed using PubMed, ISI-Web of Knowledge and The Cochrane Library. We also scrutinized material from the United Nations and World Health Organization databases (UNWHO) and the Human Fertilization and Embryology Authority (HFEA). RESULTS AND CONCLUSIONS Although ICSI results in average fertilization rates of 70%, complete or virtually complete fertilization failure still occurs in 1-5% of ICSI cycles. While oocyte activation failure can, in some cases, be overcome by artificial oocyte activators such as calcium ionophores, a more physiological oocyte activation agent might release Ca(2+) within the oocyte in a more efficient and controlled manner. As PLCζ is now widely considered to be the physiological agent responsible for activating mammalian oocytes, it represents both a novel diagnostic biomarker of oocyte activation capability and a possible mode of treatment for certain types of male infertility.
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Affiliation(s)
- J Kashir
- Nuffield Department of Obstetrics and Gynaecology, Level 3, Women's Centre, John Radcliffe Hospital, Headington, Oxford OX3 9DU, UK
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Kumada T, Yamanaka Y, Kitano A, Shibata M, Awaya T, Kato T, Okawa K, Abe T, Oshima N, Nakahata T, Heike T. Ttyh1, a Ca2+-binding protein localized to the endoplasmic reticulum, is required for early embryonic development. Dev Dyn 2010; 239:2233-45. [DOI: 10.1002/dvdy.22348] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
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27
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Yin X, Eckberg WR. Characterization of phospholipases C beta and gamma and their possible roles in Chaetopterus egg activation. Mol Reprod Dev 2009; 76:460-70. [PMID: 18951372 DOI: 10.1002/mrd.20961] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Intracellular calcium release from the endoplasmic reticulum is a hallmark at egg activation of both vertebrates and invertebrates. This fertilization-associated calcium release results from generation of the second messenger inositol 1,4,5-trisphosphate (IP(3)) by one or more phospholipases C (PLC). We characterized Chaetopterus PLCbeta and gamma by reverse transcription/degenerate oligonucleotide primed PCR and rapid amplification of cDNA end PCR. Phylogenetic analyses suggested that the deduced PLCbeta protein shared the greatest homology with mammalian PLCbeta4; the deduced PLCgamma protein shared the greatest homology with starfish PLCgamma and diverged from mammalian PLCgamma before mammalian the PLCgamma1 and gamma2 isoforms diverged. Western blot analyses with specific anti-PLCbeta and gamma antibodies, respectively, revealed that 135 and 150 kDa proteins were expressed in eggs. The general PLC antagonist U-73122 blocked fertilization-induced egg activation; however, the inactive analog, U-73343, had no effect on egg activation. We further tested whether egg activation was G protein-PLCbeta and/or protein tyrosine kinase-PLCgamma dependent. Cholera and pertussis toxins, well-known effectors of G proteins, had no effect on egg activation; while two antagonists of PTK, genistein and tyrphostin B42, inhibited both fertilization-induced and artificial egg activation. Taken together, our studies suggested that PLC activity from eggs contributes to Chaetopterus egg activation and PLCgamma might play an important role during this biological process.
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Affiliation(s)
- Xunqin Yin
- Department of Biology, Howard University, Washington, District of Columbia, USA
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28
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Feng D, Zhou Y, Ling B, Gao T, Shi Y, Wei H, Tian Z. Effects of the conditioned medium of mesenchymal stem cells on mouse oocyte activation and development. Braz J Med Biol Res 2009; 42:506-14. [DOI: 10.1590/s0100-879x2009000600006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2008] [Accepted: 03/11/2009] [Indexed: 11/22/2022] Open
Affiliation(s)
| | | | - B. Ling
- Anhui Medical University; Anhui Medical University, China
| | - T. Gao
- Anhui Medical University, China
| | | | - H.M. Wei
- University of Science and Technology of China, China
| | - Z.G. Tian
- University of Science and Technology of China, China
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29
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Vanderheyden V, Devogelaere B, Missiaen L, De Smedt H, Bultynck G, Parys JB. Regulation of inositol 1,4,5-trisphosphate-induced Ca2+ release by reversible phosphorylation and dephosphorylation. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2008; 1793:959-70. [PMID: 19133301 DOI: 10.1016/j.bbamcr.2008.12.003] [Citation(s) in RCA: 151] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Revised: 11/27/2008] [Accepted: 12/03/2008] [Indexed: 12/12/2022]
Abstract
The inositol 1,4,5-trisphosphate (IP3) receptor (IP3R) is a universal intracellular Ca2+-release channel. It is activated after cell stimulation and plays a crucial role in the initiation and propagation of the complex spatio-temporal Ca2+ signals that control cellular processes as different as fertilization, cell division, cell migration, differentiation, metabolism, muscle contraction, secretion, neuronal processing, and ultimately cell death. To achieve these various functions, often in a single cell, exquisite control of the Ca2+ release is needed. This review aims to highlight how protein kinases and protein phosphatases can interact with the IP3R or with associated proteins and so provide a large potential for fine tuning the Ca2+-release activity and for creating efficient Ca2+ signals in subcellular microdomains.
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Affiliation(s)
- Veerle Vanderheyden
- Laboratory of Molecular and Cellular Signalling, Department Molecular and Cellular Biology, Campus Gasthuisberg O/N1-K. U. Leuven, Herestraat 49-Bus 802, B-3000 Leuven, Belgium
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30
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Yanagida K, Fujikura Y, Katayose H. The present status of artificial oocyte activation in assisted reproductive technology. Reprod Med Biol 2008; 7:133-142. [PMID: 29699294 PMCID: PMC5907121 DOI: 10.1111/j.1447-0578.2008.00210.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Intracytoplasmic sperm injection (ICSI) is the most effective treatment for achieving fertilization in assisted reproductive technology (ART). However, fertilization failure occurs. The incidence of fertilization failure after ICSI is 1-5%. Approximately 50% of fertilization failure cases could be attributed to the abnormality of sperm factor. As the fertilization fails after ICSI using mature sperm, round spermatids and globozoospermia, artificial oocyte activation may provide a means of improving fertilization rates in such cases. The oocyte activation treatments used in clinical research include calcium (Ca) ionophore treatment, electrostimulation and strontium treatment. In terms of the efficiency of oocyte activation, electrostimulation and Ca ionophore gave better outcomes than strontium treatment. Strontium treatment causes Ca2+ oscillations in mice, so it has been viewed favorably. However, in human oocytes calcium oscillation has not been observed. The fertilization rate after ICSI was low in the case of globozoospermia and wiht round spermatids. Some cases of pregnancy were achieved by ICSI alone and oocyte activation methods were not essential in these cases. Among the various oocyte activation methods currently used, it should be noted that issues of genetic safety have not been addressed for the combined use of these oocyte activation methods. (Reprod Med Biol 2008; 7: 133-142).
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Affiliation(s)
- Kaoru Yanagida
- Center for Infertility and IVF, International University of Health and Welfare Hospital, Nasushiobarashi, Tochigi, Japan
| | - Yoko Fujikura
- Center for Infertility and IVF, International University of Health and Welfare Hospital, Nasushiobarashi, Tochigi, Japan
| | - Haruo Katayose
- Center for Infertility and IVF, International University of Health and Welfare Hospital, Nasushiobarashi, Tochigi, Japan
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31
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Eckert JJ, Fleming TP. Tight junction biogenesis during early development. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2008; 1778:717-28. [DOI: 10.1016/j.bbamem.2007.09.031] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2007] [Revised: 09/13/2007] [Accepted: 09/17/2007] [Indexed: 01/12/2023]
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32
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Dumollard R, Campbell K, Halet G, Carroll J, Swann K. Regulation of cytosolic and mitochondrial ATP levels in mouse eggs and zygotes. Dev Biol 2008; 316:431-40. [PMID: 18342302 DOI: 10.1016/j.ydbio.2008.02.004] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2007] [Revised: 01/23/2008] [Accepted: 02/05/2008] [Indexed: 11/25/2022]
Abstract
Fertilization activates development by stimulating a plethora of ATP consuming processes that must be provided for by an up-regulation of energy production in the zygote. Sperm-triggered Ca(2+) oscillations are known to be responsible for the stimulation of both ATP consumption and ATP supply but the mechanism of up regulation of energy production at fertilization is still unclear. By measuring [Ca(2+)] and [ATP] in the mitochondria of fertilized mouse eggs we demonstrate that sperm entry triggers Ca(2+) oscillations in the cytosol that are transduced into mitochondrial Ca(2+) oscillations pacing mitochondrial ATP production. This results, during fertilization, in an increase in both [ATP](mito) and [ATP](cyto). We also observe the stimulation of ATP consumption accompanying fertilization by monitoring [Ca(2+)](cyto) and [ATP](cyto) during fertilization of starved eggs. Our observations reveal that lactate, in contrast to pyruvate, does not fuel mitochondrial ATP production in the zygote. Therefore lactate-derived pyruvate is somehow diverted from mitochondrial oxidation and may be channeled to other metabolic routes. Together with our earlier findings, this study confirms the essential role for exogenous pyruvate in the up-regulation of ATP production at the onset of development, and suggests that lactate, which does not fuel energetic metabolism may instead regulate the intracellular redox potential.
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Affiliation(s)
- Rémi Dumollard
- Laboratoire de Biologie du Développement UMR 7009 CNRS/Paris VI, Observatoire, Station Zoologique, Villefranche sur Mer, 06230, France.
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33
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Ducibella T, Fissore R. The roles of Ca2+, downstream protein kinases, and oscillatory signaling in regulating fertilization and the activation of development. Dev Biol 2008; 315:257-79. [PMID: 18255053 DOI: 10.1016/j.ydbio.2007.12.012] [Citation(s) in RCA: 126] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2007] [Revised: 12/12/2007] [Accepted: 12/13/2007] [Indexed: 12/12/2022]
Abstract
Reviews in Developmental Biology have covered the pathways that generate the all-important intracellular calcium (Ca(2+)) signal at fertilization [Miyazaki, S., Shirakawa, H., Nakada, K., Honda, Y., 1993a. Essential role of the inositol 1,4,5-trisphosphate receptor/Ca(2+) release channel in Ca(2+) waves and Ca(2+) oscillations at fertilization of mammalian eggs. Dev. Biol. 158, 62-78; Runft, L., Jaffe, L., Mehlmann, L., 2002. Egg activation at fertilization: where it all begins. Dev. Biol. 245, 237-254] and the different temporal responses of Ca(2+) in many organisms [Stricker, S., 1999. Comparative biology of calcium signaling during fertilization and egg activation in animals. Dev. Biol. 211, 157-176]. Those reviews raise the importance of identifying how Ca(2+) causes the events of egg activation (EEA) and to what extent these temporal Ca(2+) responses encode developmental information. This review covers recent studies that have analyzed how these Ca(2+) signals are interpreted by specific proteins, and how these proteins regulate various EEA responsible for the onset of development. Many of these proteins are protein kinases (CaMKII, PKC, MPF, MAPK, MLCK) whose activity is directly or indirectly regulated by Ca(2+), and whose amount increases during late oocyte maturation. We cover biochemical progress in defining the signaling pathways between Ca(2+) and the EEA, as well as discuss how oscillatory or multiple Ca(2+) signals are likely to have specific advantages biochemically and/or developmentally. These emerging concepts are put into historical context, emphasizing that key contributions have come from many organisms. The intricate interdependence of Ca(2+), Ca(2+)-dependent proteins, and the EEA raise many new questions for future investigations that will provide insight into the extent to which fertilization-associated signaling has long-range implications for development. In addition, answers to these questions should be beneficial to establishing parameters of egg quality for human and animal IVF, as well as improving egg activation protocols for somatic cell nuclear transfer to generate stem cells and save endangered species.
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Affiliation(s)
- Tom Ducibella
- Department of OB/GYN, Tufts-New England Medical Center, Boston, MA 02111, USA.
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34
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Bedford-Guaus SJ, Yoon SY, Fissore RA, Choi YH, Hinrichs K. Microinjection of mouse phospholipase Cζ complementary RNA into mare oocytes induces long-lasting intracellular calcium oscillations and embryonic development. Reprod Fertil Dev 2008; 20:875-83. [DOI: 10.1071/rd08115] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2008] [Accepted: 07/27/2008] [Indexed: 11/23/2022] Open
Abstract
Methods presently used to activate mare oocytes for assisted reproduction technologies provide low rates of advanced embryonic development. Because phospholipase Cζ (PLCζ) is the postulated sperm-borne factor responsible for oocyte activation at fertilisation, the aim of the present study was to investigate the pattern of [Ca2+]i oscillations and developmental rates achieved by microinjection of three concentrations of mouse PLCζ complementary (c) RNA (1, 0.5 or 0.25 μg μL–1) into mare oocytes. The frequency of [Ca2+]i oscillations was no different (P > 0.05) after injection of 1, 0.5 or 0.25 μg μL–1 PLCζ cRNA (41.1 ± 5.3, 47 ± 4.0 and 55.4 ± 9.0, respectively). However, [Ca2+]i oscillations persisted longest (P < 0.05) for oocytes injected with 0.5 μg μL–1 PLCζ cRNA (570.7 ± 64.2 min). There was no significant difference in cleavage rates after injection of the three concentrations of PLCζ (P > 0.05; range 97–100%), but the proportion of oocytes reaching advanced stages of embryonic development (>64 nuclei) was significantly lower for oocytes injected with 0.25 μg μL–1 PLCζ cRNA (3%) than for those injected with 1 μg μL–1 PLCζ cRNA (15%). Based on these results, microinjection of PLCζ may prove an effective and consistent method for the parthenogenetic activation of mare oocytes for nuclear transfer and provides a physiologically relevant tool with which to study fertilisation-dependent [Ca2+]i signalling in this species.
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35
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Martín-Romero FJ, Ortíz-de-Galisteo JR, Lara-Laranjeira J, Domínguez-Arroyo JA, González-Carrera E, Alvarez IS. Store-operated calcium entry in human oocytes and sensitivity to oxidative stress. Biol Reprod 2007; 78:307-15. [PMID: 18003943 DOI: 10.1095/biolreprod.107.064527] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
Calcium signaling is a cellular event that plays a key role at many steps of fertilization and early development. However, little is known regarding the contribution of extracellular Ca(2+) influx into the cell to this signaling in gametes and early embryos. To better know the significance of calcium entry on oocyte physiology, we have evaluated the mechanism of store-operated calcium entry (SOCE) in human metaphase II (MII) oocytes and its sensitivity to oxidative stress, one of the major factors implicated in the outcome of in vitro fertilization (IVF) techniques. We show that depletion of intracellular Ca(2+) stores through inhibition of sarco(endo)plasmic Ca(2+)-ATPase with thapsigargin triggers Ca(2+) entry in resting human oocytes. Ba(2+) and Mn(2+) influx was also stimulated following inhibition, and Ca(2+) entry was sensitive to pharmacological inhibition because the SOCE blocker 2-aminoethoxydiphenylborate (2-APB) reduced calcium and barium entry. These results support the conclusion that there is a plasma membrane mechanism responsible for the capacitative divalent cation entry in human oocytes. Moreover, the Ca(2+) entry mechanism described in MII oocytes was found to be highly sensitive to oxidative stress. Hydrogen peroxide, at micromolar concentrations that could mimic culture conditions in IVF, elicited an increase of [Ca(2+)](i) that was dependent on the presence of extracellular Ca(2+). This rise was preventable by 2-APB, indicating that it was mainly due to the enhanced influx through store-operated calcium channels. In sum, our results demonstrate the occurrence of SOCE in human MII oocytes and the modification of this pathway due to oxidative stress, with possible consequences in IVF.
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Affiliation(s)
- Francisco Javier Martín-Romero
- Departamento de Bioquímicay Biología Molecular, Reproduction and Development Group (REDES), Universidad de Extremadura, Badajoz-06071, Spain.
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36
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McGinnis LK, Albertini DF, Kinsey WH. Localized activation of Src-family protein kinases in the mouse egg. Dev Biol 2007; 306:241-54. [PMID: 17449027 PMCID: PMC2694733 DOI: 10.1016/j.ydbio.2007.03.024] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2006] [Revised: 03/15/2007] [Accepted: 03/16/2007] [Indexed: 10/23/2022]
Abstract
Recent studies in species that fertilize externally have demonstrated that fertilization triggers localized activation of Src-family protein kinases in the egg cortex. However, the requirement for Src-family kinases in activation of the mammalian egg is different from lower species and the objective of this study was to characterize changes in the distribution and activity of Src-family protein tyrosine kinases (PTKs) during zygotic development in the mouse. Immunofluorescence analysis of mouse oocytes and zygotes with an anti-phosphotyrosine antibody revealed that fertilization stimulated accumulation of P-Tyr-containing proteins in the egg cortex and that their abundance was elevated in the region overlying the MII spindle. In addition, the poles of the MII spindle exhibited elevated P-Tyr levels. As polar body extrusion progressed, P-Tyr-containing proteins were especially concentrated in the region of cortex adjacent to the maternal chromatin and the forming polar body. In contrast, P-Tyr labeling of the spindle poles eventually disappeared as meiosis II progressed to anaphase II. In approximately 24% of cases, the fertilizing sperm nucleus was associated with increased P-Tyr labeling in the overlying cortex and oolemma. To determine whether Src-family protein tyrosine kinases could be responsible for the observed changes in the distribution of P-Tyr containing proteins, an antibody to the activated form of Src-family PTKs was used to localize activated Src, Fyn or Yes. Activated Src-family kinases were found to be strongly associated with the meiotic spindle at all stages of meiosis II; however, no concentration of labeling was evident at the egg cortex. The absence of cortical Src-family PTK activity continued until the blastocyst stage when strong cortical activity became evident. At the pronuclear stage, activated Src-family PTKs became concentrated around the pronuclei in close association with the nuclear envelope. This pattern was unique to the earliest stages of development and disappeared by the eight cell stage. Functional studies using chemical inhibitors and a dominant-negative Fyn construct demonstrated that Src-family PTKs play an essential role in completion of meiosis II following fertilization and progression from the pronuclear stage into mitosis. These data suggest that while Src-family PTKs are not required for fertilization-induced calcium oscillations, they do play a critical role in development of the zygote. Furthermore, activation of these kinases in the mouse egg is limited to distinct regions and occurs at specific times after fertilization.
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Affiliation(s)
| | | | - William H. Kinsey
- To whom correspondence should be addressed: Department of Anatomy and Cell Biology, University of Kansas Medical Center, 3901 Rainbow Blvd., Kansas City, KS 66160. Tel.: 913-588-2721; Fax: 913-588-2710.
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37
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Meng L, Luo J, Li C, Kinsey WH. Role of Src homology 2 domain-mediated PTK signaling in mouse zygotic development. Reproduction 2006; 132:413-21. [PMID: 16940282 DOI: 10.1530/rep.1.01151] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Fyn and other Src-family kinases play an essential role at several steps during egg activation following fertilization of externally fertilizing species, such as marine invertebrates, fish, and frogs. Recent studies demonstrate that the requirement for Src-family kinases in activation of the mammalian egg is different from lower species, and the objective of this study was to test the role of the Fyn kinase in the mouse egg activated by intracytoplasmic sperm injection (ICSI). An Src homology 2 (SH2) domain containing fusion protein was used to suppress Fyn function in the mouse zygote following ICSI. Eggs injected with the Fyn SH2 domain at an intracellular concentration of 4–8 μM exhibited reduced developmental potential with 100% of the zygotes being arrested following the first or the second cleavage. At higher concentrations, the protein blocked pronuclear congression and the zygotes remained at the pronuclear stage. The SH2 domain had no effect on sperm-induced calcium oscillations in distinct contrast to its effect on the eggs of lower species. The results indicate that the SH2 domain of Fyn kinase plays an important role in pronuclear congression as well as early cleavage events and that this effect appears not to involve disruption of calcium oscillations.
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Affiliation(s)
- Li Meng
- Center for Reproductive Sciences and Department of Anatomy and Cell Biology, University of Kansas Medical Center, 3901 Rainbow Boulevard, Kansas City, Kansas 66160, USA
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38
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Sato KI, Fukami Y, Stith BJ. Signal transduction pathways leading to Ca2+ release in a vertebrate model system: Lessons from Xenopus eggs. Semin Cell Dev Biol 2006; 17:285-92. [PMID: 16584903 DOI: 10.1016/j.semcdb.2006.02.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
At fertilization, eggs unite with sperm to initiate developmental programs that give rise to development of the embryo. Defining the molecular mechanism of this fundamental process at the beginning of life has been a key question in cell and developmental biology. In this review, we examine sperm-induced signal transduction events that lead to release of intracellular Ca(2+), a pivotal trigger of developmental activation, during fertilization in Xenopus laevis. Recent data demonstrate that metabolism of inositol 1,4,5-trisphosphate (IP(3)), a second messenger for Ca(2+) release, is carefully regulated and involves phospholipase C (PLC) and the tyrosine kinase Src. Roles of other potential regulators in this pathway, such as phosphatidylinositol 3-kinase, heterotrimeric GTP-binding protein, phospholipase D (PLD) and phosphatidic acid (PA) are also discussed. Finally, we address roles of egg lipid/membrane microdomains or 'rafts' as a platform for the sperm-egg membrane interaction and subsequent signaling events of egg activation.
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Affiliation(s)
- Ken-ichi Sato
- Laboratory of Molecular Biology, The Research Center for Environmental Genomics, Kobe University, Kobe 657-8501, Japan.
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39
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Loren J, Lacham-Kaplan O. The employment of strontium to activate mouse oocytes: effects on spermatid-injection outcome. Reproduction 2006; 131:259-67. [PMID: 16452719 DOI: 10.1530/rep.1.00894] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The present research investigated the effects of various strontium concentrations, in combination with different incubation periods, on mouse parthenogentic oocyte activation and blastocyst development. The results for blastocyst development showed a trend indicating that 10 mM strontium for 3 h was the optimal strontium protocol. Ethanol, an agent that incites oocyte activation via a monotonic rise in calcium, was employed as a control. The outcome of blastocyst formation arising from parthenogenic ethanol activation was significantly less (P< 0.001) than that achieved by the optimal strontium protocol. To assess the impact of strontium oocyte activation on embryo viability following fertilization with immature germ cells, the protocol of 10 mM strontium for 3 h was applied to oocytes injected with round spermatids and then compared with other protocols. The results indicate that following round-spermatid injection the benefits derived from strontium artificial oocyte activation are evident during both pre- and post-implantation development. However, in order to adjust the protocol to the most effective round-spermatid injection in relation to the oocyte cell cycle, injection was done 1.5 h after strontium activation followed by another 1.5 h activation in strontium. The implementation of round-spermatid injection in combination with this oocyte-activation protocol led to live-birth outcomes not significantly different to those outcomes obtained by mature spermatozoa.
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Affiliation(s)
- Jean Loren
- Monash Immunology and Stem Cell Laboratories, Level 3, STRIP 1- Building 75, Monash University, Wellington Rd., Clayton, Australia, 3800
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40
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Nishi Y, Lin R. DYRK2 and GSK-3 phosphorylate and promote the timely degradation of OMA-1, a key regulator of the oocyte-to-embryo transition in C. elegans. Dev Biol 2005; 288:139-49. [PMID: 16289132 DOI: 10.1016/j.ydbio.2005.09.053] [Citation(s) in RCA: 72] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Revised: 09/27/2005] [Accepted: 09/27/2005] [Indexed: 11/23/2022]
Abstract
Oocyte maturation and fertilization initiates a dynamic and tightly regulated process in which a non-dividing oocyte is transformed into a rapidly dividing embryo. We have shown previously that two C. elegans CCCH zinc finger proteins, OMA-1 and OMA-2, have an essential and redundant function in oocyte maturation. Both OMA-1 and OMA-2 are expressed only in oocytes and 1-cell embryos, and need to be degraded rapidly after the first mitotic division for embryogenesis to proceed normally. We report here a distinct redundant function for OMA-1 and OMA-2 in the 1-cell embryo. Depletion of both oma-1 and oma-2 in embryos leads to embryonic lethality. We also show that OMA-1 protein is directly phosphorylated at T239 by the DYRK kinase MBK-2, and that phosphorylation at T239 is required both for OMA-1 function in the 1-cell embryo and its degradation after the first mitosis. OMA-1 phosphorylated at T239 is only detected within a short developmental window of 1-cell embryos, beginning soon after the proposed activation of MBK-2. Phosphorylation at T239 facilitates subsequent phosphorylation of OMA-1 by another kinase, GSK-3, at T339 in vitro. Phosphorylation at both T239 and T339 are essential for correctly-timed OMA-1 degradation in vivo. We propose that a series of precisely-timed phosphorylation events regulates both the activity and the timing of degradation for OMA proteins, thereby allowing restricted and distinct functions of OMA-1 and OMA-2 in the maturing oocyte and 1-cell embryo, ensuring a normal oocyte-to-embryo transition in C. elegans.
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Affiliation(s)
- Yuichi Nishi
- Department of Molecular Biology, University of Texas Southwestern Medical Center, 6000 Harry Hines Blvd., Dallas, TX 75390-9148, USA
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41
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Campbell KHS, Alberio R, Choi I, Fisher P, Kelly RDW, Lee JH, Maalouf W. Cloning: Eight Years After Dolly. Reprod Domest Anim 2005; 40:256-68. [PMID: 16008756 DOI: 10.1111/j.1439-0531.2005.00591.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
It is now 8 years since the birth of Dolly, the first animal produced by nuclear transfer using a donor cell population established from an adult animal. During this time, the technique of nuclear transfer has been successfully applied to a range of mammalian species for the production of offspring using a plethora of donor cell types derived from both foetal and adult tissues. In addition, when coupled with genetic manipulation of the donor cells, transgenic offspring have been produced with a range of genetic modifications including gene knockouts and gene knockings. Despite the apparent successes of the technology, the efficiency of development to live offspring has remained low and developmental abnormalities still occur. The objectives of this paper are to review some of the successes and failures of the nuclear transfer procedure since the production of Dolly. In particular, we will review the major steps in the procedure and discuss studies from our laboratory and others which have modified the procedure in ways which may impact on development.
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Affiliation(s)
- K H S Campbell
- Animal Development and Biotechnology Group, Division of Animal Physiology, University of Nottingham, School of Biosciences, Sutton Bonington, Loughborough, Leics LE12 5RD, UK.
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42
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Abstract
Fertilization is the union of a single sperm and an egg, an event that results in a diploid embryo. Animals use many mechanisms to achieve this ratio; the most prevalent involves physically blocking the fusion of subsequent sperm. Selective pressures to maintain monospermy have resulted in an elaboration of diverse egg and sperm structures. The processes employed for monospermy are as diverse as the animals that result from this process. Yet, the fundamental molecular requirements for successful monospermic fertilization are similar, implying that animals may have a common ancestral block to polyspermy. Here, we explore this hypothesis, reviewing biochemical, molecular, and genetic discoveries that lend support to a common ancestral mechanism. We also consider the evolution of alternative or radical techniques, including physiological polyspermy, with respect to our ability to describe a parsimonious guide to fertilization.
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Affiliation(s)
- Julian L Wong
- Department of Molecular Biology, Cellular Biology, and Biochemistry, Brown University, Providence, Rhode Island 02912, USA
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43
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Voronina E, Wessel GM. βγ subunits of heterotrimeric G-proteins contribute to Ca2+ release at fertilization in the sea urchin. J Cell Sci 2004; 117:5995-6005. [PMID: 15536121 DOI: 10.1242/jcs.01518] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A cytoplasmic Ca2+ transient is required for egg activation at fertilization in all animals. The pathway leading to release of Ca2+ from the endoplasmic reticulum in echinoderms includes activation of a SRC homolog, followed by phospholipase Cγ activation, and formation of inositol trisphosphate. However, the upstream activators or modulators of this signaling pathway are not known. We recently identified four Gα subunits of heterotrimeric G-proteins present in the sea urchin egg, and here we find that activation of G-proteins of the Gαs and Gαq type, but not Gαi or Gα12 type, is required for normal Ca2+ dynamics at fertilization. The effects of these G-proteins are mediated by the Gβγ subunits, occur upstream of the cytoplasmic Ca2+ release, and influence both the amplitude of Ca2+ release and the duration of the lag phase. We propose integration of the G-protein input into the framework of signaling at sea urchin fertilization.
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Affiliation(s)
- Ekaterina Voronina
- Department of Molecular and Cell Biology and Biochemistry, Brown University, 69 Brown Street, Providence, RI 02912, USA
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44
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Carroll J, FitzHarris G, Marangos P, Halet G. Ca2+ signalling and cortical re-organisation during the transition from meiosis to mitosis in mammalian oocytes. Eur J Obstet Gynecol Reprod Biol 2004; 115 Suppl 1:S61-7. [PMID: 15196718 DOI: 10.1016/j.ejogrb.2004.01.024] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
In mammals, the mature ovulated egg is arrested in metaphase II of the first meiotic division. The signal that triggers the transition from meiosis to mitosis is provided by the fertilising sperm and takes the form of a series of Ca(2+) oscillations. The pattern of Ca(2+) oscillations is imposed by maternal control mechanisms that ensure Ca(2+) transients occur during M-phase of meiosis II and during the first mitotic division. The transition from meiosis to mitosis involves a major re-organisation. The unfertilised egg is polarised with the meiotic spindle located in the cortex of the animal pole and clusters of endoplasmic reticulum in the vegetal hemisphere. By the time of the first mitotic division some 20h later the spindle has formed in the centre of the embryo and is surrounded by endoplasmic reticulum. These changes in organisation have implications for the inheritance of ER in meiotic and mitotic cell divisions and may reflect different roles and requirements for Ca(2+) in meiosis and mitosis.
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Affiliation(s)
- John Carroll
- Department of Physiology, University College London, Gower Street, London WC1E 6BT, UK.
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45
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Swann K, Larman MG, Saunders CM, Lai FA. The cytosolic sperm factor that triggers Ca2+ oscillations and egg activation in mammals is a novel phospholipase C: PLCzeta. Reproduction 2004; 127:431-9. [PMID: 15047934 DOI: 10.1530/rep.1.00169] [Citation(s) in RCA: 122] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
When sperm activate eggs at fertilization the signal for activation involves increases in the intracellular free Ca2+ concentration. In mammals the Ca2+ changes at fertilization consist of intracellular Ca2+ oscillations that are driven by the generation of inositol 1,4,5-trisphosphate (InsP3). It is not established how sperm trigger the increases in InsP3 and Ca2+ at fertilization. One theory suggests that sperm initiate signals to activate the egg by introducing a specific factor into the egg cytoplasm after membrane fusion. This theory has been mainly based upon the observation that injecting a cytosolic sperm protein factor into eggs can trigger the same pattern of Ca2+ oscillations induced by the sperm. We have recently shown that this soluble sperm factor protein is a novel form of phospholipase C (PLC), and it is referred to as PLCzeta(zeta). We describe the evidence that led to the identification of PLCzeta and discuss the issues relating to its potential role in fertilization.
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Affiliation(s)
- K Swann
- Department of Anatomy and Developmental Biology, University College London, London WC1E 6BT, UK.
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Talmor-Cohen A, Tomashov-Matar R, Eliyahu E, Shapiro R, Shalgi R. Are Src family kinases involved in cell cycle resumption in rat eggs? Reproduction 2004; 127:455-63. [PMID: 15047936 DOI: 10.1530/rep.1.00104] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The earliest visible indications for the transition to embryos in mammalian eggs, known as egg activation, are cortical granules exocytosis (CGE) and resumption of meiosis (RM); these events are triggered by the fertilizing spermatozoon through a series of Ca2+ transients. The pathways, within the egg, leading to the intracellular Ca2+ release and to the downstream cellular events, are currently under intensive investigation. The involvement of Src family kinases (SFKs) in Ca2+ release at fertilization is well supported in marine invertebrate eggs but not in mammalian eggs. In a previous study we have shown the expression and localization of Fyn, the first SFK member demonstrated in the mammalian egg. The purpose of the current study was to identify other common SFKs and resolve their function during activation of mammalian eggs. All three kinases examined: Fyn, c-Src and c-Yes are distributed throughout the egg cytoplasm. However, Fyn and c-Yes tend to concentrate at the egg cortex, though only Fyn is localized to the spindle as well. The different localizations of the various SFKs imply the possibility of their different functions within the egg. To examine whether SFKs participate in the signal transduction pathways during egg activation, we employed selective inhibitors of the SFKs activity (PP2 and SU6656). The results demonstrate that RM, which is triggered by Ca2+ elevation, is an SFK-dependent process, while CGE, triggered by either Ca2+ elevation or protein kinase C (PKC), is not. The possible involvement of SFKs in the signal transduction pathways that lead from the sperm-egg fusion site downstream of the Ca2+ release remains unclear.
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Affiliation(s)
- A Talmor-Cohen
- Department of Cell and Developmental Biology, Sackler Faculty of Medicine, Tel Aviv University, Ramat-Aviv 69978, Tel-Aviv, Israel
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Dumollard R, Marangos P, Fitzharris G, Swann K, Duchen M, Carroll J. Sperm-triggered [Ca2+] oscillations and Ca2+ homeostasis in the mouse egg have an absolute requirement for mitochondrial ATP production. Development 2004; 131:3057-67. [PMID: 15163630 DOI: 10.1242/dev.01181] [Citation(s) in RCA: 178] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
At fertilisation, repetitive increases in the intracellular Ca2+ concentration, [Ca2+]i, drive the completion of meiosis and initiate the development of the quiescent egg into an embryo. Although the requirement for an ATP supply is evident, the relative roles of potential ATP sources remains unclear in the mammalian egg, and the specific role of mitochondria in [Ca2+]i regulation as well as in the sperm-triggered [Ca2+] oscillations is unknown. We have used fluorescence and luminescence imaging to investigate mitochondrial activity in single mouse eggs. Simultaneous imaging of mitochondrial redox state (NADH and flavoprotein autofluorescence) and [Ca2+]i revealed that sperm-triggered [Ca2+] oscillations are transmitted to the mitochondria where they directly stimulate mitochondrial activity. Inhibition of mitochondrial oxidative phosphorylation caused release of Ca2+ from the endoplasmic reticulum because of local ATP depletion. Mitochondrial ATP production is an absolute requirement for maintaining a low resting [Ca2+]i and for sustaining sperm-triggered [Ca2+] oscillations. Luminescence measurements of intracellular [ATP] from single eggs confirmed that mitochondrial oxidative phosphorylation is the major source of ATP synthesis in the dormant unfertilised egg. These observations show that a high local ATP consumption is balanced by mitochondrial ATP production, and that balance is critically poised. Mitochondrial ATP supply and demand are thus closely coupled in mouse eggs. As mitochondrial ATP generation is essential to sustain the [Ca2+] signals that are crucial to initiate development, mitochondrial integrity is clearly fundamental in sustaining fertility in mammalian eggs.
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Affiliation(s)
- Rémi Dumollard
- Department of Physiology, University College London, Gower Street, London, WC1E 6BT, UK.
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Larman MG, Saunders CM, Carroll J, Lai FA, Swann K. Cell cycle-dependent Ca2+ oscillations in mouse embryos are regulated by nuclear targeting of PLCζ. J Cell Sci 2004; 117:2513-21. [PMID: 15159452 DOI: 10.1242/jcs.01109] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
During the first cell cycle Ca2+ oscillations are regulated in a cell cycle-dependent manner, such that the oscillations are unique to M phase. How the Ca2+ oscillations are regulated with such cell cycle stage-dependency is unknown, despite their importance for egg activation and embryo development. We recently identified a novel, sperm-specific phospholipase C (PLCzeta; PLCζ) that triggers Ca2+ oscillations similar to those caused by sperm. We show that PLCζ-induced Ca2+ oscillations also occur exclusively during M phase. The cell cycle-dependency can be explained by PLCζ's localisation to the pronuclei, which depends specifically upon a nuclear localisation signal sequence. Preventing pronuclear localisation of PLCζ by mutation of the nuclear localisation signal, or by inhibiting pronuclear formation/import, can prolong Ca2+ oscillations or allow them to occur during interphase. These data suggest a novel mechanism for regulating a PLC through nuclear sequestration and may explain the cell cycle-dependent regulation of Ca2+ oscillations following fertilisation.
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Affiliation(s)
- Mark G Larman
- Department of Anatomy and Developmental Biology, University College London, WC1E 6BT, UK
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Bedford SJ, Kurokawa M, Hinrichs K, Fissore RA. Patterns of Intracellular Calcium Oscillations in Horse Oocytes Fertilized by Intracytoplasmic Sperm Injection: Possible Explanations for the Low Success of This Assisted Reproduction Technique in the Horse1. Biol Reprod 2004; 70:936-44. [PMID: 14656727 DOI: 10.1095/biolreprod.103.021485] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
In all species studied, fertilization induces intracellular Ca2+ ([Ca2+]i) oscillations required for oocyte activation and embryonic development. This species-specific pattern has not been studied in the equine, partly due to the difficulties linked to in vitro fertilization in this species. Therefore, the objective of this study was to use intracytoplasmic sperm injection (ICSI) to investigate fertilization-induced [Ca2+]i signaling and, possibly, ascertain problems linked to the success of this technology in the horse. In vivo- and in vitro-matured mare oocytes were injected with a single motile stallion sperm. Few oocytes displayed [Ca2+]i responses regardless of oocyte source and we hypothesized that this may result from insufficient release of the sperm-borne active molecule (sperm factor) into the oocyte. However, permeabilization of sperm membranes with Triton-X or by sonication did not alleviate the deficient [Ca2+]i responses in mare oocytes. Thus, we hypothesized that a step downstream of release, possibly required for sperm factor function, is not appropriately accomplished in horse oocytes. To test this, ICSI-fertilized horse oocytes were fused to unfertilized mouse oocytes, which are known to respond with [Ca2+]i oscillations to injection of stallion sperm, and [Ca2+]i monitoring was performed. Such pairs consistently displayed [Ca2+]i responses demonstrating that the sperm factor is appropriately released into the ooplasm of horse oocytes, but that these are unable to activate and/or provide the appropriate substrate that is required for the sperm factor delivered by ICSI to initiate oscillations. These findings may have implications to improve the success of ICSI in the equine and other livestock species.
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Affiliation(s)
- Sylvia J Bedford
- Department of Veterinary and Animal Sciences, University of Massachusetts, Amherst, Massachusetts 01003, USA
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Van Blerkom J, Davis P, Alexander S. Occurrence of maternal and paternal spindles in unfertilized human oocytes: possible relationship to nucleation defects after silent fertilization. Reprod Biomed Online 2004; 8:454-9. [PMID: 15149570 DOI: 10.1016/s1472-6483(10)60930-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Experience with conventional clinical IVF indicates that a first cleavage can occur in the absence of detectable pronuclear formation (so-called silent fertilization). In these instances, the first division is often asymmetrical and delayed when compared with normally fertilized siblings. In this study, DNA configurations and spindle organization were examined by fluorescence microscopy in metaphase II human oocytes that remained unfertilized after conventional IVF and were considered likely candidates for silent fertilization. The results show comparatively high frequencies of penetration in the absence of detectable pronuclear evolution, and that both a maternal meiotic and a sperm-derived mitotic-like spindle can coexist in the same oocyte. Patterns of cell division and blastomere nucleation in silent fertilizations suggest the possibility that this division may involve uniparental chromosomal segregation in which maternal and paternal DNA is differentially partitioned into daughter blastomeres. This pattern of inheritance may generate certain types of ploidy and nucleation defects detected at the 2- to 4-cell stage.
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Affiliation(s)
- Jonathan Van Blerkom
- Department of Molecular, Cellular and Developmental Biology, University of Colorado, Boulder, CO 80309, USA.
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