1
|
Taher L, Israel S, Drexler HCA, Makalowski W, Suzuki Y, Fuellen G, Boiani M. The proteome, not the transcriptome, predicts that oocyte superovulation affects embryonic phenotypes in mice. Sci Rep 2021; 11:23731. [PMID: 34887460 PMCID: PMC8660899 DOI: 10.1038/s41598-021-03054-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 11/26/2021] [Indexed: 11/18/2022] Open
Abstract
Superovulation is the epitome for generating oocytes for molecular embryology in mice, and it is used to model medically assisted reproduction in humans. However, whether a superovulated oocyte is normal, is an open question. This study establishes for the first time that superovulation is associated with proteome changes that affect phenotypic traits in mice, whereas the transcriptome is far less predictive. The proteins that were differentially expressed in superovulated mouse oocytes and embryos compared to their naturally ovulated counterparts were enriched in ontology terms describing abnormal mammalian phenotypes: a thinner zona pellucida, a smaller oocyte diameter, increased frequency of cleavage arrest, and defective blastocyst formation, which could all be verified functionally. Moreover, our findings indicate that embryos with such abnormalities are negatively selected during preimplantation, and ascribe these abnormalities to incomplete ovarian maturation during the time of the conventional superovulation, since they could be corrected upon postponement of the ovulatory stimulus by 24 h. Our data place constraints on the common view that superovulated oocytes are suitable for drawing general conclusions about developmental processes, and underscore the importance of including the proteins in a modern molecular definition of oocyte quality.
Collapse
Affiliation(s)
- Leila Taher
- Institute of Biomedical Informatics, Graz University of Technology, Stremayrgasse 16/I, 8010, Graz, Austria.
| | - Steffen Israel
- Max Planck Institute for Molecular Biomedicine, Roentgenstrasse 20, 48149, Muenster, Germany
| | - Hannes C A Drexler
- Max Planck Institute for Molecular Biomedicine, Roentgenstrasse 20, 48149, Muenster, Germany
| | - Wojciech Makalowski
- Institute of Bioinformatics, Faculty of Medicine, University of Münster, Niels Stensen Str. 14, 48149, Münster, Germany
| | - Yutaka Suzuki
- Department of Medical Genome Sciences, Graduate School of Frontier Sciences, University of Tokyo, Kashiwa, Chiba, 277-8562, Japan
| | - Georg Fuellen
- Institute for Biostatistics and Informatics in Medicine and Aging Research (IBIMA), Rostock University Medical Center, Ernst-Heydemann-Strasse 8, 18057, Rostock, Germany.
| | - Michele Boiani
- Max Planck Institute for Molecular Biomedicine, Roentgenstrasse 20, 48149, Muenster, Germany.
| |
Collapse
|
2
|
Zona Pellucida Genes and Proteins: Essential Players in Mammalian Oogenesis and Fertility. Genes (Basel) 2021; 12:genes12081266. [PMID: 34440440 PMCID: PMC8391237 DOI: 10.3390/genes12081266] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 08/03/2021] [Accepted: 08/10/2021] [Indexed: 12/17/2022] Open
Abstract
All mammalian oocytes and eggs are surrounded by a relatively thick extracellular matrix (ECM), the zona pellucida (ZP), that plays vital roles during oogenesis, fertilization, and preimplantation development. Unlike ECM surrounding somatic cells, the ZP is composed of only a few glycosylated proteins, ZP1–4, that are unique to oocytes and eggs. ZP1–4 have a large region of polypeptide, the ZP domain (ZPD), consisting of two subdomains, ZP-N and ZP-C, separated by a short linker region, that plays an essential role in polymerization of nascent ZP proteins into crosslinked fibrils. Both subdomains adopt immunoglobulin (Ig)-like folds for their 3-dimensional structure. Mouse and human ZP genes are encoded by single-copy genes located on different chromosomes and are highly expressed in the ovary by growing oocytes during late stages of oogenesis. Genes encoding ZP proteins are conserved among mammals, and their expression is regulated by cis-acting sequences located close to the transcription start-site and by the same/similar trans-acting factors. Nascent ZP proteins are synthesized, packaged into vesicles, secreted into the extracellular space, and assembled into long, crosslinked fibrils that have a structural repeat, a ZP2-ZP3 dimer, and constitute the ZP matrix. Fibrils are oriented differently with respect to the oolemma in the inner and outer layers of the ZP. Sequence elements in the ZPD and the carboxy-terminal propeptide of ZP1–4 regulate secretion and assembly of nascent ZP proteins. The presence of both ZP2 and ZP3 is required to assemble ZP fibrils and ZP1 and ZP4 are used to crosslink the fibrils. Inactivation of mouse ZP genes by gene targeting has a detrimental effect on ZP formation around growing oocytes and female fertility. Gene sequence variations in human ZP genes due to point, missense, or frameshift mutations also have a detrimental effect on ZP formation and female fertility. The latter mutations provide additional support for the role of ZPD subdomains and other regions of ZP polypeptide in polymerization of human ZP proteins into fibrils and matrix.
Collapse
|
3
|
Abstract
The zona pellucida (ZP) is an extracellular matrix that surrounds all mammalian oocytes, eggs, and early embryos and plays vital roles during oogenesis, fertilization, and preimplantation development. The ZP is composed of three or four glycosylated proteins, ZP1–4, that are synthesized, processed, secreted, and assembled into long, cross-linked fibrils by growing oocytes. ZP proteins have an immunoglobulin-like three-dimensional structure and a ZP domain that consists of two subdomains, ZP-N and ZP-C, with ZP-N of ZP2 and ZP3 required for fibril assembly. A ZP2–ZP3 dimer is located periodically along ZP fibrils that are cross-linked by ZP1, a protein with a proline-rich N terminus. Fibrils in the inner and outer regions of the ZP are oriented perpendicular and parallel to the oolemma, respectively, giving the ZP a multilayered appearance. Upon fertilization of eggs, modification of ZP2 and ZP3 results in changes in the ZP's physical and biological properties that have important consequences. Certain structural features of ZP proteins suggest that they may be amyloid-like proteins.
Collapse
Affiliation(s)
- Eveline S. Litscher
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;,
| | - Paul M. Wassarman
- Department of Cell, Developmental, and Regenerative Biology, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA;,
| |
Collapse
|
4
|
Fahrenkamp E, Algarra B, Jovine L. Mammalian egg coat modifications and the block to polyspermy. Mol Reprod Dev 2020; 87:326-340. [PMID: 32003503 PMCID: PMC7155028 DOI: 10.1002/mrd.23320] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 12/16/2019] [Indexed: 01/15/2023]
Abstract
Fertilization by more than one sperm causes polyploidy, a condition that is generally lethal to the embryo in the majority of animal species. To prevent this occurrence, eggs have developed a series of mechanisms that block polyspermy at the level of the plasma membrane or their extracellular coat. In this review, we first introduce the mammalian egg coat, the zona pellucida (ZP), and summarize what is currently known about its composition, structure, and biological functions. We then describe how this specialized extracellular matrix is modified by the contents of cortical granules (CG), secretory organelles that are exocytosed by the egg after gamete fusion. This process releases proteases, glycosidases, lectins and zinc onto the ZP, resulting in a series of changes in the properties of the egg coat that are collectively referred to as hardening. By drawing parallels with comparable modifications of the vitelline envelope of nonmammalian eggs, we discuss how CG‐dependent modifications of the ZP are thought to contribute to the block to polyspermy. Moreover, we argue for the importance of obtaining more information on the architecture of the ZP, as well as systematically investigating the many facets of ZP hardening.
Collapse
Affiliation(s)
- Eileen Fahrenkamp
- Department of Biosciences and Nutrition & Center for Innovative Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Blanca Algarra
- Department of Biosciences and Nutrition & Center for Innovative Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Luca Jovine
- Department of Biosciences and Nutrition & Center for Innovative Medicine, Karolinska Institutet, Huddinge, Sweden
| |
Collapse
|
5
|
Abstract
Biogenesis of the zona pellucida (ZP), the extracellular coat that surrounds all mammalian eggs, is a universal and essential feature of mammalian oogenesis and reproduction. The mouse egg's ZP consists of only three glycoproteins, called ZP1-3, that are synthesized, secreted, and assembled into an extracellular coat exclusively by growing oocytes during late stages of oogenesis while oocytes are arrested in meiosis. Expression of ZP genes and synthesis of ZP1-3 are gender-specific. Nascent ZP1-3 are synthesized by oocytes as precursor polypeptides that possess several elements necessary for their secretion and assembly into a matrix of long fibrils outside of growing oocytes. Failure to synthesize either ZP2 or ZP3 by homozygous null female mice precludes formation of a ZP during oocyte growth and, due to faulty folliculogenesis and a paucity of ovulated eggs, results in infertility. High-resolution structural analyses suggest that ZP glycoproteins consist largely of immunoglobulin (Ig)-like folds and that the glycoproteins probably arose by duplication of a common Ig-like domain. Mouse ZP1-3 share many features, particularly a ZP domain, with extracellular coat glycoproteins of eggs from other vertebrate and invertebrate animals whose origins date back more than 600 million years. These and other aspects of ZP biogenesis are discussed in this review.
Collapse
Affiliation(s)
- Paul M Wassarman
- Department of Developmental and Regenerative Biology, Mount Sinai School of Medicine, New York, USA.
| | | |
Collapse
|
6
|
Kim MS, Bae CY, Wee G, Han YM, Park JK. A microfluidicin vitrocultivation system for mechanical stimulation of bovine embryos. Electrophoresis 2009; 30:3276-82. [DOI: 10.1002/elps.200900157] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
7
|
Hasegawa A, Kanazawa N, Sawai H, Komori S, Koyama K. Pig zona pellucida 2 (pZP2) protein does not participate in zona pellucida formation in transgenic mice. Reproduction 2006; 132:455-64. [PMID: 16940286 DOI: 10.1530/rep.1.01016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The zona pellucida, an extracellular matrix surrounding mammalian oocytes, is composed of three or four glycoproteins. It is well known that the zona pellucida plays several critical roles during fertilization, but there is little knowledge about its formation. The purpose of this study is to examine whether a pig zona pellucida glycoprotein 2 (pZP2) would assemble with mouse zona pellucida. A transgene construct was prepared by placing a minigene encoding pZP2 downstream from the promoter of mouse ZP2. The result showed that the transgenic protein was synthesized in growing oocytes but not incorporated into the zona pellucida. Furthermore, the pZP2 transgene did not rescue the phenotype in ZP2-knockout zona-deficient mice. These results indicate that pZP2 does not participate in mouse zona pellucida formation and the zona pellucida is constituted from its component proteins in a molecular species-specific manner between mice and pigs.
Collapse
Affiliation(s)
- Akiko Hasegawa
- Laboratory of Developmental Biology and Reproduction, Hyogo College of Medicine, Institute for Advanced Medical Sciences, Nishinomiya, Japan
| | | | | | | | | |
Collapse
|
8
|
Coonrod SA, Calvert ME, Reddi PP, Kasper EN, Digilio LC, Herr JC. Oocyte proteomics: localisation of mouse zona pellucida protein 3 to the plasma membrane of ovulated mouse eggs. Reprod Fertil Dev 2004. [DOI: 10.1071/rd03079] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
In order to gain a deeper understanding of the molecular underpinnings of sperm–egg interaction and early development, we have used two-dimensional (2D) electrophoresis, avidin blotting and tandem mass spectrometry to identify, clone and characterise abundant molecules from the mouse egg proteome. Two-dimensional avidin blots of biotinylated zona-free eggs revealed an abundant approximately 75-kDa surface-labelled heterogeneous protein possessing a staining pattern similar to that of the zona pellucida glycoprotein, mouse ZP3 (mZP3). In light of this observation, we investigated whether mZP3 specifically localises to the plasma membrane of mature eggs. Zona pellucidae of immature mouse oocytes and mature eggs were removed using acid Tyrode’s solution, chymotrypsin or mechanical shearing. Indirect immunofluorescence using the mZP3 monoclonal antibody (mAb) IE-10 demonstrated strong continuous staining over the entire surface of immature oocytes and weak microvillar staining on ovulated eggs, regardless of the method of zona removal. Interestingly, in mature eggs, increased fluorescence intensity was observed following artificial activation and fertilisation, whereas little to no fluorescence was observed in degenerated eggs. The surface localisation of ZP3 on mature eggs was supported by the finding that the IE-10 mAb immunoprecipitated an approximate 75-kDa protein from lysates of biotinylated zona-free eggs. To further investigate the specificity of the localisation of mZP3 to the oolemma, indirect immunofluorescence was performed using the IE-10 mAb on both CV-1 and CHO cells transfected with full-length recombinant mZP3 (re-mZP3). Plasma membrane targeting of the expressed re-mZP3 protein was observed in both cell lines. The membrane association of re-mZP3 was confirmed by the finding that biotinylated re-mZP3 (approximately 75 kDa) is immunoprecipitated from the hydrophobic phase of Triton X-114 extracts of transfected cells following phase partitioning. Immunoprecipitation assays also demonstrated that surface re-mZP3 was released from transfected CV-1 in a time-dependent manner. These results demonstrate that ZP3 is specifically associated with the surface of mature eggs and its subsequent release from the cell surface may represent one mechanism by which ZP3 is secreted. Furthermore, the increase in ZP3 surface expression following fertilisation suggests that ZP3 may have a functional role during sperm–oolemma binding and fusion. These results also validate the usefulness of using the 2D proteomic approach to identify and characterise egg-surface proteins.
Collapse
|
9
|
|
10
|
Qi H, Williams Z, Wassarman PM. Secretion and assembly of zona pellucida glycoproteins by growing mouse oocytes microinjected with epitope-tagged cDNAs for mZP2 and mZP3. Mol Biol Cell 2002; 13:530-41. [PMID: 11854410 PMCID: PMC65647 DOI: 10.1091/mbc.01-09-0440] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The zona pellucida (ZP) is a highly organized extracellular coat that surrounds all mammalian eggs. The mouse egg ZP is composed of three glycoproteins, called mZP1-3, that are synthesized, secreted, and assembled into a ZP exclusively by growing oocytes. Here, we microinjected epitope-tagged (Myc and Flag) cDNAs for mZP2 and mZP3 into the germinal vesicle (nucleus) of growing oocytes isolated from juvenile mice. Specific antibodies and laser scanning confocal microscopy were used to follow nascent, recombinant ZP glycoproteins in both permeabilized and nonpermeabilized oocytes. When such cDNAs were injected, epitope-tagged mZP2 (Myc-mZP2) and mZP3 (Flag-mZP3) were synthesized, packaged into large intracellular vesicles, and secreted by the vast majority of oocytes. Secreted glycoproteins were incorporated into only the innermost layer of the thickening ZP, and the amount of nascent glycoprotein in this region increased with increasing time of oocyte culture. Consistent with prior observations, the putative transmembrane domain at the C terminus of mZP2 and mZP3 was missing from nascent glycoprotein incorporated into the ZP. When the consensus furin cleavage site near the C terminus of mZP3 was mutated, such that it should not be cleaved by furin, secretion and assembly of mZP3 was reduced. On the other hand, mZP3 incorporated into the ZP lacked the transmembrane domain downstream of the mutated furin cleavage site, suggesting that some other protease(s) excised the domain. These results strongly suggest that nascent mZP2 and mZP3 are incorporated into only the innermost layer of the ZP and that excision of the C-terminal region of the glycoproteins is required for assembly into the oocyte ZP.
Collapse
Affiliation(s)
- Huayu Qi
- Department of Biochemistry and Molecular Biology, Mount Sinai School of Medicine, New York, New York 10029-6574, USA
| | | | | |
Collapse
|
11
|
Abstract
Fertilization in mammalian and nonmammalian organisms has many features in common. These features include a final maturation phase for sperm and eggs, species-specific binding of sperm to eggs, penetration by sperm of one or more extracellular coats surrounding eggs, fusion of sperm and eggs, and activation of eggs. Implicit in this are a variety of basic molecular events, including receptor-ligand interactions, signalling cascades, specific proteolysis, and nuclear transformations. Here, several of these events are addressed for fertilization in animals as diverse as starfish and mice.
Collapse
Affiliation(s)
- P M Wassarman
- Department of Cell Biology and Anatomy, Mount Sinai School of Medicine, New York, New York 10029-6574, USA.
| |
Collapse
|