1
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Wang W, Malka R, Lindemeier M, Cyprys P, Tiedemann S, Sun K, Zhang X, Xiong H, Sprunck S, Sun MX. EGG CELL 1 contributes to egg-cell-dependent preferential fertilization in Arabidopsis. NATURE PLANTS 2024; 10:268-282. [PMID: 38287093 DOI: 10.1038/s41477-023-01616-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 12/20/2023] [Indexed: 01/31/2024]
Abstract
During double fertilization in angiosperms, the pollen tube delivers two sperm cells into an embryo sac; one sperm cell fuses with an egg cell, and the other sperm cell fuses with the central cell. It has long been proposed that the preference for fusion with one or another female gamete cell depends on the sperm cells and occurs during gamete recognition. However, up to now, sperm-dependent preferential fertilization has not been demonstrated, and results on preferred fusion with either female gamete have remained conflicting. To investigate this topic, we generated Arabidopsis thaliana mutants that produce single sperm-like cells or whose egg cells are eliminated; we found that although the three different types of sperm-like cell are functionally equivalent in their ability to fertilize the egg and the central cell, each type of sperm-like cell fuses predominantly with the egg cell. This indicates that it is the egg cell that controls its preferential fertilization. We also found that sperm-activating small secreted EGG CELL 1 proteins are involved in the regulation of egg-cell-dependent preferential fertilization, revealing another important role for this protein family during double fertilization.
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Affiliation(s)
- Wei Wang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Raphael Malka
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Maria Lindemeier
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Philipp Cyprys
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Sophie Tiedemann
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Kaiting Sun
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Xuecheng Zhang
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China
| | - Hanxian Xiong
- School of Life Science and Technology, Wuhan Polytechnic University, Wuhan, China.
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany.
| | - Meng-Xiang Sun
- State Key Laboratory of Hybrid Rice, College of Life Sciences, Wuhan University, Wuhan, China.
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2
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Li T, Zhu S, Li Y, Yao J, Wang C, Fang S, Pan J, Chen W, Zhang Y. Characteristic of GEX1 genes reveals the essential roles for reproduction in cotton. Int J Biol Macromol 2023; 253:127645. [PMID: 37879575 DOI: 10.1016/j.ijbiomac.2023.127645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2023] [Revised: 09/30/2023] [Accepted: 10/22/2023] [Indexed: 10/27/2023]
Abstract
GEX1 (gamete expressed 1) proteins are critical membrane proteins conserved among flowering plants that are involved in the nuclear fusion and embryonic development. Herein, we identified the 32 GEX1 proteins from representative land plants. In cotton, GEX1 genes expressed in various tissues across all stages of the life cycle, especially in pollen. Subcellular localization indicated the position of GhGEX1 protein was localized in the endoplasmic reticulum. Experimental research has demonstrated that GhGEX1 has the potential to improve the partial abortion phenotype in Arabidopsis. CRISPR/Cas9-mediated knockout of GhGEX1 exhibited the seed abortion. Paraffin section of the ovule revealed that the polar nuclear fusion of ghgex1 plants remains at a standstill when the wild type has developed into a normal embryo. Comparative transcriptome analysis showed that the DEGs of reproductive-related processes and membrane-related processes were repressed in the pollen of knockout lines. The predicted protein interactions showed that GhGEX1 probably functioned through interactions with proteins related to reproduction and membrane. From all these investigations, it was possible to conclude that the GEX1 proteins are evolutionarily conserved in flowering plants and elucidated the pivotal roles during fertilization and early embryonic development in cotton.
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Affiliation(s)
- Tengyu Li
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Science, Anyang 455000, China; National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan 430070, China
| | - Shouhong Zhu
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Science, Anyang 455000, China
| | - Yan Li
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Science, Anyang 455000, China
| | - Jinbo Yao
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Science, Anyang 455000, China
| | - Chenlei Wang
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Science, Anyang 455000, China
| | - Shengtao Fang
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Science, Anyang 455000, China
| | - Jingwen Pan
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Science, Anyang 455000, China
| | - Wei Chen
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Science, Anyang 455000, China.
| | - Yongshan Zhang
- National Key Laboratory of Cotton Bio-breeding and Integrated Utilization, Institute of Cotton Research, Chinese Academy of Agricultural Science, Anyang 455000, China.
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3
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Sugi N, Izumi R, Tomomi S, Susaki D, Kinoshita T, Maruyama D. Removal of the endoplasma membrane upon sperm cell activation after pollen tube discharge. FRONTIERS IN PLANT SCIENCE 2023; 14:1116289. [PMID: 36778680 PMCID: PMC9909283 DOI: 10.3389/fpls.2023.1116289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Accepted: 01/17/2023] [Indexed: 06/18/2023]
Abstract
In pollen and pollen tubes, immotile sperm cells are enclosed by an inner vegetative plasma membrane (IVPM), a single endomembrane originating from the vegetative-cell plasma membrane. It is widely believed that sperm cells must be removed from the IVPM prior to gamete associations and fusions; however, details of the timing and morphological changes upon IVPM dissociation remain elusive. Here, we report a rapid IVPM breakdown immediately before double fertilization in Arabidopsis thaliana. The IVPM was stably observed in coiling pollen tubes when pollen tube discharge was prevented using lorelei mutant ovules. In contrast, a semi-in vivo fertilization assay in wild-type ovules demonstrated fragmented IVPM around sperm nuclei 1 min after pollen tube discharge. These observations revealed the dynamic alteration of released sperm cells and provided new insights into double fertilization in flowering plants. With a summary of recent findings on IVPM lipid composition, we discussed the possible physiological signals controlling IVPM breakdown.
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4
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Li L, Hou S, Xiang W, Song Z, Wang Y, Zhang L, Li J, Gu H, Dong J, Dresselhaus T, Zhong S, Qu LJ. The egg cell is preferentially fertilized in Arabidopsis double fertilization. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2022; 64:2039-2046. [PMID: 36165373 PMCID: PMC9968529 DOI: 10.1111/jipb.13370] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Accepted: 09/23/2022] [Indexed: 05/28/2023]
Abstract
In flowering plants (angiosperms), fertilization of the egg cell by one sperm cell produces an embryo, whereas fusion of a second sperm cell with the central cell generates the endosperm. In most angiosperms like Arabidopsis, a pollen grain contains two isomorphic sperm cells required for this double fertilization process. A long-standing unsolved question is whether the two fertilization events have any preference. A tool to address this question is the usage of the cyclin-dependent kinase a1 (cdka;1) mutant pollen, which produces a single sperm-like cell (SLC). Here, we first adopt a complementation-based fluorescence-labeling method to successfully separate and collect cdka;1 mutant pollen containing a single SLC. Single-cell RNA-sequencing analysis revealed that cdka;1 SLCs show a gene expression profile highly similar to that of sperm cells and not to the generative cell, precursor of the two sperm cells. Pollination assays using a limited number of cdka;1 mutant pollen revealed that in 98.2% of the ovules, single fertilization of the egg cell occurred. Pollination of pistils with excessive cdka;1 mutant pollen allowed the delivery of a second SLC via fertilization recovery, which fertilized the central cell, resulting in 20.7% double-fertilized ovules. This indicates that cdka;1 SLCs are able to fertilize both the egg and the central cell. Taken together, our findings have answered a long-standing question and support that preferential fertilization of the egg cell is evident in Arabidopsis.
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Affiliation(s)
- Ling Li
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Saiying Hou
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Wei Xiang
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Zihan Song
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Yuan Wang
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Li Zhang
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Jing Li
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, College of Bioscience and Resources Environment, Beijing University of Agriculture, Beijing 102206, China
| | - Hongya Gu
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
- The National Plant Gene Research Center, Beijing 100101, China
| | - Juan Dong
- The Waksman Institute of Microbiology, Rutgers the State University of New Jersey, Piscataway, NJ“2” 08854, USA
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg 93053, Germany
| | - Sheng Zhong
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
| | - Li-Jia Qu
- State Key Laboratory for Protein and Plant Gene Research, Peking-Tsinghua Center for Life Sciences at College of Life Sciences, Peking University, Beijing 100871, China
- The National Plant Gene Research Center, Beijing 100101, China
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5
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Chen SY, Wang L, Jia PF, Yang WC, Sze H, Li HJ. Osmoregulation determines sperm cell geometry and integrity for double fertilization in flowering plants. MOLECULAR PLANT 2022; 15:1488-1496. [PMID: 35918896 DOI: 10.1016/j.molp.2022.07.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 07/05/2022] [Accepted: 07/22/2022] [Indexed: 06/15/2023]
Abstract
Distinct from the motile flagellated sperm of animals and early land plants, the non-motile sperm cells of flowering plants are carried in the pollen grain to the female pistil. After pollination, a pair of sperm cells are delivered into the embryo sac by pollen tube growth and rupture. Unlike other walled plant cells with an equilibrium between internal turgor pressure and mechanical constraints of the cell walls, sperm cells wrapped inside the cytoplasm of a pollen vegetative cell have only thin and discontinuous cell walls. The sperm cells are uniquely ellipsoid in shape, although it is unclear how they maintain this shape within the pollen tubes and after release. In this study, we found that genetic disruption of three endomembrane-associated cation/H+ exchangers specifically causes sperm cells to become spheroidal in hydrated pollens of Arabidopsis. Moreover, the released mutant sperm cells are vulnerable and rupture before double fertilization, leading to failed seed set, which can be partially rescued by depletion of the sperm-expressed vacuolar water channel. These results suggest a critical role of cell-autonomous osmoregulation in adjusting the sperm cell shape for successful double fertilization in flowering plants.
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Affiliation(s)
- Shu-Yan Chen
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lan Wang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Peng-Fei Jia
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Wei-Cai Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Heven Sze
- Department of Cell Biology & Molecular Genetics, University of Maryland, College Park, MD 20742, USA
| | - Hong-Ju Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China.
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6
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Ajayi OO, Held MA, Showalter AM. Glucuronidation of type II arabinogalactan polysaccharides function in sexual reproduction of Arabidopsis. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2022; 109:164-181. [PMID: 34726315 DOI: 10.1111/tpj.15562] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 10/25/2021] [Indexed: 06/13/2023]
Abstract
Arabinogalactan proteins (AGPs) are complex, hyperglycosylated plant cell wall proteins with little known about the biological roles of their glycan moieties in sexual reproduction. Here, we report that GLCAT14A, GLCAT14B, and GLCAT14C, three enzymes responsible for the addition of glucuronic acid residues to AGPs, function in pollen development, polytubey block, and normal embryo development in Arabidopsis. Using biochemical and immunolabeling techniques, we demonstrated that the loss of function of the GLCAT14A, GLCAT14B, and GLCAT14C genes resulted in disorganization of the reticulate structure of the exine wall, abnormal development of the intine layer, and collapse of pollen grains in glcat14a/b and glcat14a/b/c mutants. Synchronous development between locules within the same anther was also lost in some glcat14a/b/c stamens. In addition, we observed excessive attraction of pollen tubes targeting glcat14a/b/c ovules, indicating that the polytubey block mechanism was compromised. Monosaccharide composition analysis revealed significant reductions in all sugars in glcat14a/b and glcat14a/b/c mutants except for arabinose and galactose, while immunolabeling showed decreased amounts of AGP sugar epitopes recognized by glcat14a/b and glcat14a/b/c mutants compared with the wild type. This work demonstrates the important roles that AG glucuronidation plays in Arabidopsis sexual reproduction and reproductive development.
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Affiliation(s)
- Oyeyemi O Ajayi
- Department of Environmental and Plant Biology, Ohio University, Athens, OH, 45701, USA
- Molecular and Cellular Biology Program, Ohio University, Athens, OH, 45701, USA
| | - Michael A Held
- Molecular and Cellular Biology Program, Ohio University, Athens, OH, 45701, USA
- Department of Chemistry and Biochemistry, Ohio University, Athens, OH, 45701, USA
| | - Allan M Showalter
- Department of Environmental and Plant Biology, Ohio University, Athens, OH, 45701, USA
- Molecular and Cellular Biology Program, Ohio University, Athens, OH, 45701, USA
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7
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Ju Y, Yuan J, Jones DS, Zhang W, Staiger CJ, Kessler SA. Polarized NORTIA accumulation in response to pollen tube arrival at synergids promotes fertilization. Dev Cell 2021; 56:2938-2951.e6. [PMID: 34672969 DOI: 10.1016/j.devcel.2021.09.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 07/28/2021] [Accepted: 09/28/2021] [Indexed: 11/30/2022]
Abstract
Signal-mediated regulation of protein trafficking is an elegant mechanism for controlling the delivery of molecules to a precise location for critical signaling events that occur over short time frames. During plant reproduction, the FERONIA receptor complex is critical for intercellular communication that leads to gamete delivery; however, the impact of the FERONIA signal transduction cascade on protein trafficking in synergid cells remains unknown. Live imaging of pollen tube reception has revealed that a key outcome of FERONIA signaling is polar accumulation of the MLO protein NORTIA at the filiform apparatus in response to signals from an arriving pollen tube. Artificial delivery of NORTIA to the filiform apparatus is sufficient to bypass the FERONIA signaling pathway and to promote interspecific pollen tube reception. We propose that polar accumulation of NORTIA leads to the production of a secondary booster signal to ensure that pollen tubes burst to deliver the sperm cells for double fertilization.
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Affiliation(s)
- Yan Ju
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA; Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Jing Yuan
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA; Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Daniel S Jones
- Department of Microbiology and Plant Biology, University of Oklahoma, Norman, OK 73019, USA
| | - Weiwei Zhang
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA; Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Christopher J Staiger
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA; Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA; Department of Biological Sciences, Purdue University, West Lafayette, IN 47907, USA
| | - Sharon A Kessler
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA; Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA.
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8
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Abstract
The gametophyte represents the sexual phase in the alternation of generations in plants; the other, nonsexual phase is the sporophyte. Here, we review the evolutionary origins of the male gametophyte among land plants and, in particular, its ontogenesis in flowering plants. The highly reduced male gametophyte of angiosperm plants is a two- or three-celled pollen grain. Its task is the production of two male gametes and their transport to the female gametophyte, the embryo sac, where double fertilization takes place. We describe two phases of pollen ontogenesis-a developmental phase leading to the differentiation of the male germline and the formation of a mature pollen grain and a functional phase representing the pollen tube growth, beginning with the landing of the pollen grain on the stigma and ending with double fertilization. We highlight recent advances in the complex regulatory mechanisms involved, including posttranscriptional regulation and transcript storage, intracellular metabolic signaling, pollen cell wall structure and synthesis, protein secretion, and phased cell-cell communication within the reproductive tissues.
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Affiliation(s)
- Said Hafidh
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 165 02 Prague 6, Czech Republic; ,
| | - David Honys
- Laboratory of Pollen Biology, Institute of Experimental Botany of the Czech Academy of Sciences, 165 02 Prague 6, Czech Republic; ,
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9
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Nagahara S, Takeuchi H, Higashiyama T. Polyspermy Block in the Central Cell During Double Fertilization of Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2021; 11:588700. [PMID: 33510743 PMCID: PMC7835324 DOI: 10.3389/fpls.2020.588700] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Accepted: 12/10/2020] [Indexed: 06/01/2023]
Abstract
During double fertilization in angiosperms, two male gametes (sperm cells), are released from a pollen tube into the receptive region between two female gametes; the egg cell and the central cell of the ovule. The sperm cells fertilize the egg cell and the central cell in a one-to-one manner to yield a zygote and an endosperm, respectively. The one-to-one distribution of the sperm cells to the two female gametes is strictly regulated, possibly via communication among the four gametes. Polyspermy block is the mechanism by which fertilized female gametes prevent fertilization by a secondary sperm cell, and has been suggested to operate in the egg cell rather than the central cell. However, whether the central cell also has the ability to avoid polyspermy during double fertilization remains unclear. Here, we assessed the one-to-one fertilization mechanism of the central cell by laser irradiation of the female gametes and live cell imaging of the fertilization process in Arabidopsis thaliana. We successfully disrupted an egg cell within the ovules by irradiation using a femtosecond pulse laser. In the egg-disrupted ovules, the central cell predominantly showed single fertilization by one sperm cell, suggesting that neither the egg cell nor its fusion with one sperm cell is necessary for one-to-one fertilization (i.e., monospermy) of the central cell. In addition, using tetraspore mutants possessing multiple sperm cell pairs in one pollen, we demonstrated that normal double fertilization was observed even when excess sperm cells were released into the receptive region between the female gametes. In ovules accepting four sperm cells, the egg cell never fused with more than one sperm cell, whereas half of the central cells fused with more than one sperm cell (i.e., polyspermy) even 1 h later. Our results suggest that the central cell can block polyspermy during double fertilization, although the central cell is more permissive to polyspermy than the egg cell. The potential contribution of polyspermy block by the central cell is discussed in terms of how it is involved in the one-to-one distribution of the sperm cells to two distinct female gametes.
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Affiliation(s)
- Shiori Nagahara
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Hidenori Takeuchi
- Institute of Transformative Bio-Molecules, Nagoya University, Nagoya, Japan
- Institute for Advanced Research, Nagoya University, Nagoya, Japan
| | - Tetsuya Higashiyama
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Japan
- Institute of Transformative Bio-Molecules, Nagoya University, Nagoya, Japan
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, Tokyo, Japan
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10
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Shin JM, Yuan L, Ohme-Takagi M, Kawashima T. Cellular dynamics of double fertilization and early embryogenesis in flowering plants. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2020; 336:642-651. [PMID: 32638525 DOI: 10.1002/jez.b.22981] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2019] [Revised: 06/12/2020] [Accepted: 06/18/2020] [Indexed: 12/12/2022]
Abstract
Flowering plants (angiosperms) perform a unique double fertilization in which two sperm cells fuse with two female gamete cells in the embryo sac to develop a seed. Furthermore, during land plant evolution, the mode of sexual reproduction has been modified dramatically from motile sperm in the early-diverging land plants, such as mosses and ferns as well as some gymnosperms (Ginkgo and cycads) to nonmotile sperm that are delivered to female gametes by the pollen tube in flowering plants. Recent studies have revealed the cellular dynamics and molecular mechanisms for the complex series of double fertilization processes and elucidated differences and similarities between animals and plants. Here, together with a brief comparison with animals, we review the current understanding of flowering plant zygote dynamics, covering from gamete nuclear migration, karyogamy, and polyspermy block, to zygotic genome activation as well as asymmetrical division of the zygote. Further analyses of the detailed molecular and cellular mechanisms of flowering plant fertilization should shed light on the evolution of the unique sexual reproduction of flowering plants.
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Affiliation(s)
- Ji Min Shin
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky.,Kentucky Tobacco Research and Development Center, University of Kentucky, Lexington, Kentucky.,Graduate School of Science and Engineering, Saitama University, Saitama, Saitama, Japan
| | - Ling Yuan
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky.,Kentucky Tobacco Research and Development Center, University of Kentucky, Lexington, Kentucky
| | - Masaru Ohme-Takagi
- Graduate School of Science and Engineering, Saitama University, Saitama, Saitama, Japan.,Bioproduction Research Institute, National Institute of Advanced Industrial Science and Technology, Tsukuba, Ibaraki, Japan
| | - Tomokazu Kawashima
- Department of Plant and Soil Sciences, University of Kentucky, Lexington, Kentucky
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11
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Hater F, Nakel T, Groß-Hardt R. Reproductive Multitasking: The Female Gametophyte. ANNUAL REVIEW OF PLANT BIOLOGY 2020; 71:517-546. [PMID: 32442389 DOI: 10.1146/annurev-arplant-081519-035943] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Fertilization of flowering plants requires the organization of complex tasks, many of which become integrated by the female gametophyte (FG). The FG is a few-celled haploid structure that orchestrates division of labor to coordinate successful interaction with the sperm cells and their transport vehicle, the pollen tube. As reproductive outcome is directly coupled to evolutionary success, the underlying mechanisms are under robust molecular control, including integrity check and repair mechanisms. Here, we review progress on understanding the development and function of the FG, starting with the functional megaspore, which represents the haploid founder cell of the FG. We highlight recent achievements that have greatly advanced our understanding of pollen tube attraction strategies and the mechanisms that regulate plant hybridization and gamete fusion. In addition, we discuss novel insights into plant polyploidization strategies that expand current concepts on the evolution of flowering plants.
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Affiliation(s)
- Friederike Hater
- Centre for Biomolecular Interactions, University of Bremen, 28359 Bremen, Germany;
| | - Thomas Nakel
- Centre for Biomolecular Interactions, University of Bremen, 28359 Bremen, Germany;
| | - Rita Groß-Hardt
- Centre for Biomolecular Interactions, University of Bremen, 28359 Bremen, Germany;
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12
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Sprunck S. Twice the fun, double the trouble: gamete interactions in flowering plants. CURRENT OPINION IN PLANT BIOLOGY 2020; 53:106-116. [PMID: 31841779 DOI: 10.1016/j.pbi.2019.11.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Revised: 11/14/2019] [Accepted: 11/17/2019] [Indexed: 05/13/2023]
Abstract
During sexual reproduction two gametes of opposite sex unite to produce a zygote. Gamete fusion is a highly controlled process and it has become evident that, across species, common concepts apply to this ancient and fundamental event. Sexual reproduction in flowering plants is even more complex in that two sperm cells fertilize two female reproductive cells (egg and central cell) in a process called double fertilization. Due to the coordinated developmental progression and mutual dependency of the two fertilization products (embryo and endosperm), the success and timing of the two fusion events substantially affects seed set. So far, four proteins are known to act on the surfaces of Arabidopsis gametes to accomplish double fertilization. The molecular and evolutionary characteristics of these players prove that flowering plants integrate plant-specific and widely conserved mechanisms to accomplish the timely fusion of each sperm cell with one female reproductive cell.
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Affiliation(s)
- Stefanie Sprunck
- Cell Biology and Plant Biochemistry, University of Regensburg, Universitätsstr. 31, 93053 Regensburg, Germany.
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13
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Cyprys P, Lindemeier M, Sprunck S. Gamete fusion is facilitated by two sperm cell-expressed DUF679 membrane proteins. NATURE PLANTS 2019; 5:253-257. [PMID: 30850817 DOI: 10.1038/s41477-019-0382-3] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2018] [Accepted: 02/06/2019] [Indexed: 05/02/2023]
Abstract
Successful double fertilization in flowering plants relies on two coordinated gamete fusion events, but the underlying molecular processes are not well understood. We show that two sperm-specific DOMAIN OF UNKNOWN FUNCTION 679 membrane proteins (DMP8 and DMP9) facilitate gamete fusion, with a greater effect on sperm-egg fusion than on sperm-central cell fusion. We also show that sperm adhesion and sperm cell separation depend on egg cell-secreted EGG CELL 1 proteins.
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Affiliation(s)
- Philipp Cyprys
- Cell Biology and Plant Biochemistry, Biochemistry Centre Regensburg, University of Regensburg, Regensburg, Germany
| | - Maria Lindemeier
- Cell Biology and Plant Biochemistry, Biochemistry Centre Regensburg, University of Regensburg, Regensburg, Germany
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemistry Centre Regensburg, University of Regensburg, Regensburg, Germany.
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Zhou LZ, Dresselhaus T. Friend or foe: Signaling mechanisms during double fertilization in flowering seed plants. Curr Top Dev Biol 2018; 131:453-496. [PMID: 30612627 DOI: 10.1016/bs.ctdb.2018.11.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Since the first description of double fertilization 120 years ago, the processes of pollen tube growth and guidance, sperm cell release inside the receptive synergid cell, as well as fusion of two sperm cells to the female gametes (egg and central cell) have been well documented in many flowering plants. Especially microscopic techniques, including live cell imaging, were used to visualize these processes. Molecular as well as genetic methods were applied to identify key players involved. However, compared to the first 11 decades since its discovery, the past decade has seen a tremendous advancement in our understanding of the molecular mechanisms regulating angiosperm fertilization. Whole signaling networks were elucidated including secreted ligands, corresponding receptors, intracellular interaction partners, and further downstream signaling events involved in the cross-talk between pollen tubes and their cargo with female reproductive cells. Biochemical and structural biological approaches are now increasingly contributing to our understanding of the different signaling processes required to distinguish between compatible and incompatible interaction partners. Here, we review the current knowledge about signaling mechanisms during above processes with a focus on the model plants Arabidopsis thaliana and Zea mays (maize). The analogy that many of the identified "reproductive signaling mechanisms" also act partly or fully in defense responses and/or cell death is also discussed.
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Affiliation(s)
- Liang-Zi Zhou
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany
| | - Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, University of Regensburg, Regensburg, Germany.
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15
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Takahashi T, Mori T, Ueda K, Yamada L, Nagahara S, Higashiyama T, Sawada H, Igawa T. The male gamete membrane protein DMP9/DAU2 is required for double fertilization in flowering plants. Development 2018; 145:145/23/dev170076. [DOI: 10.1242/dev.170076] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 10/29/2018] [Indexed: 11/20/2022]
Abstract
ABSTRACT
All flowering plants exhibit a unique type of sexual reproduction called ‘double fertilization’ in which each pollen tube-delivered sperm cell fuses with an egg and a central cell. Proteins that localize to the plasma membrane of gametes regulate one-to-one gamete pairing and fusion between male and female gametes for successful double fertilization. Here, we have identified a membrane protein from Lilium longiflorum generative cells using proteomic analysis and have found that the protein is an ortholog of Arabidopsis DUF679 DOMAIN MEMBRANE PROTEIN 9 (DMP9)/DUO1-ACTIVATED UNKNOWN 2 (DAU2). The flowering plant DMP9 proteins analyzed in this study were predicted to have four transmembrane domains and be specifically expressed in both generative and sperm cells. Knockdown of DMP9 resulted in aborted seeds due to single fertilization of the central cell. Detailed imaging of DMP9-knockdown sperm cells during in vivo and semi-in vitro double fertilization revealed that DMP9 is involved in gamete interaction that leads to correct double fertilization.
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Affiliation(s)
- Taro Takahashi
- Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo-shi, Chiba 271-8510, Japan
| | - Toshiyuki Mori
- Department of Tropical Medicine and Parasitology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421, Japan
| | - Kenji Ueda
- Department of Biological Production, Akita Prefectural University, 41-438 Kaidobata-Nishi, Nakano Shimoshinjo, Akita-shi, Akita 010-0195, Japan
| | - Lixy Yamada
- Sugashima Marine Biological Laboratory, Nagoya University, Sugashima, Toba-shi, Mie 517-0004, Japan
| | - Shiori Nagahara
- Institute of Transformative Bio-Molecules, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Tetsuya Higashiyama
- Institute of Transformative Bio-Molecules, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Hitoshi Sawada
- Sugashima Marine Biological Laboratory, Nagoya University, Sugashima, Toba-shi, Mie 517-0004, Japan
| | - Tomoko Igawa
- Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo-shi, Chiba 271-8510, Japan
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16
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Tekleyohans DG, Mao Y, Kägi C, Stierhof YD, Groß-Hardt R. Polyspermy barriers: a plant perspective. CURRENT OPINION IN PLANT BIOLOGY 2017; 35:131-137. [PMID: 27951463 PMCID: PMC7610644 DOI: 10.1016/j.pbi.2016.11.012] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 11/16/2016] [Accepted: 11/17/2016] [Indexed: 05/19/2023]
Abstract
A common denominator of sexual reproduction in many eukaryotic species is the exposure of an egg to excess sperm to maximize the chances of reproductive success. To avoid potential harmful or deleterious consequences of supernumerary sperm fusion to a single female gamete (polyspermy), many eukaryotes, including plants, have evolved barriers preventing polyspermy. Typically, these checkpoints are implemented at different stages in the reproduction process. The virtual absence of unambiguous reports of naturally occurring egg cell polyspermy in flowering plants is likely reflecting the success of this multiphasic strategy and highlights the difficulty to trace this presumably rare event. We here focus on potential polyspermy avoidance mechanisms in plants and discuss them in light of analogous processes in animals.
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Affiliation(s)
- Dawit G Tekleyohans
- Bremen University, Molecular Genetics, Leobenerstr. 5, 28359, Bremen, Germany
| | - Yanbo Mao
- Bremen University, Molecular Genetics, Leobenerstr. 5, 28359, Bremen, Germany
| | - Christina Kägi
- Federal Office for Agriculture FOAG, Mattenhofstr. 5, 3003 Bern, Switzerland
| | | | - Rita Groß-Hardt
- Bremen University, Molecular Genetics, Leobenerstr. 5, 28359, Bremen, Germany.
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17
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Abstract
Compared with the animal kingdom, fertilization is particularly complex in flowering plants (angiosperms). Sperm cells of angiosperms have lost their motility and require transportation as a passive cargo by the pollen tube cell to the egg apparatus (egg cell and accessory synergid cells). Sperm cell release from the pollen tube occurs after intensive communication between the pollen tube cell and the receptive synergid, culminating in the lysis of both interaction partners. Following release of the two sperm cells, they interact and fuse with two dimorphic female gametes (the egg and the central cell) forming the major seed components embryo and endosperm, respectively. This process is known as double fertilization. Here, we review the current understanding of the processes of sperm cell reception, gamete interaction, their pre-fertilization activation and fusion, as well as the mechanisms plants use to prevent the fusion of egg cells with multiple sperm cells. The role of Ca(2+) is highlighted in these various processes and comparisons are drawn between fertilization mechanisms in flowering plants and other eukaryotes, including mammals.
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Affiliation(s)
- Thomas Dresselhaus
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93040 Regensburg, Germany.
| | - Stefanie Sprunck
- Cell Biology and Plant Biochemistry, Biochemie-Zentrum Regensburg, University of Regensburg, 93040 Regensburg, Germany
| | - Gary M Wessel
- Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, Rhode Island 02912, USA
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Simopoulou M, Gkoles L, Bakas P, Giannelou P, Kalampokas T, Pantos K, Koutsilieris M. Improving ICSI: A review from the spermatozoon perspective. Syst Biol Reprod Med 2016; 62:359-371. [PMID: 27646677 DOI: 10.1080/19396368.2016.1229365] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Intracytoplasmic sperm injection (ICSI) is the most frequently applied method for fertilization making the process of identifying the perfect spermatozoon fundamental. Herein we offer a critical and thorough presentation on the techniques reported regarding (i) handling and preparing semen samples, (ii) identifying and 'fishing' spermatozoa, and (iii) improving key factors, such as motility for a successful ICSI practice. These approaches are suggested to make the process easier and more effective especially in atypical and challenging circumstances. Furthermore, we present an epigrammatic opinion-where appropriate-based upon our collective experience. Techniques such as intracytoplasmic morphologically selected sperm injection, hyaluronic binding, polarized light microscopy, and annexin V agent identification for comparing sperm cells and their chromatin integrity are analyzed. Moreover, for the demanding cases of total sperm immotility the use of the hypoosmotic swelling test, methylxanthines, as well as the option of laser assisted immotile sperm selection are discussed. Finally, we refer to the employment of myoinositol as a way to bioreactively improve ICSI outcome for oligoasthenoteratozoospermic men. The diversity and the constant development of novel promising techniques to improve ICSI from the spermatozoon perspective, is certainly worth pursuing. The majority of the techniques discussed are still a long way from being established in routine practices of the standard IVF laboratory. In most cases an experienced embryologist could yield the same results. Although some of the techniques show great benefits, there is a need for large scale multicenter randomized control studies to be conducted in order to specify their importance before suggesting horizontal application. Taking into consideration the a priori invasive nature of ICSI, when clinical application becomes a possibility we need to proceed with caution and ensure that in the pursuit for innovation we are not sacrificing safety and the balance of the physiological and biological pathways of the spermatozoon's dynamic. ABBREVIATIONS ICSI: intracytoplasmic sperm injection; IVF: in vitro fertilization; PGD: reimplantation genetic diagnosis; IVM: in vitro maturation; HCV/HIV: hepatitis C virus/human immunodeficiency virus; IMSI: intracytoplasmic morphologically selected sperm injection; DGC: density gradient centrifugations; S-U: swim-up; ART: assisted reproduction technology; IUI: intrauterine insemination; PVP: polyvinylpyrrolidone; HA: hyaluronic acid; MSOME: motile sperm organelle morphology examination; ZP: zona pellucida; MACS: magnetic activation cell sorting; HOST: hypo-osmotic swelling test; TESE: testicular sperm extraction; MMP: mitochondrial membrane potential; OAT: oligoasthenoteratozoospermic.
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Affiliation(s)
- Mara Simopoulou
- a Department of Physiology, Medical School, National and Kapodistrian University of Athens , Athens , Greece.,b Assisted Conception Unit, 2nd Department of Obstetrics and Gynecology , Aretaieion Hospital, Medical School, National and Kapodistrian University of Athens , Athens , Greece
| | - Laertis Gkoles
- b Assisted Conception Unit, 2nd Department of Obstetrics and Gynecology , Aretaieion Hospital, Medical School, National and Kapodistrian University of Athens , Athens , Greece
| | - Panagiotis Bakas
- b Assisted Conception Unit, 2nd Department of Obstetrics and Gynecology , Aretaieion Hospital, Medical School, National and Kapodistrian University of Athens , Athens , Greece
| | - Polina Giannelou
- b Assisted Conception Unit, 2nd Department of Obstetrics and Gynecology , Aretaieion Hospital, Medical School, National and Kapodistrian University of Athens , Athens , Greece
| | - Theodoros Kalampokas
- b Assisted Conception Unit, 2nd Department of Obstetrics and Gynecology , Aretaieion Hospital, Medical School, National and Kapodistrian University of Athens , Athens , Greece
| | | | - Michael Koutsilieris
- a Department of Physiology, Medical School, National and Kapodistrian University of Athens , Athens , Greece
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Mori T, Kawai-Toyooka H, Igawa T, Nozaki H. Gamete Dialogs in Green Lineages. MOLECULAR PLANT 2015; 8:1442-54. [PMID: 26145252 DOI: 10.1016/j.molp.2015.06.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 06/15/2015] [Accepted: 06/28/2015] [Indexed: 05/20/2023]
Abstract
Gamete fusion is a core process of sexual reproduction and, in both plants and animals, different sex gametes fuse within species. Although most of the molecular factors involved in gamete interaction are still unknown in various sex-possessing eukaryotes, reports of such factors in algae and land plants have been increasing in the past decade. In particular, knowledge of gamete interaction in flowering plants and green algae has increased since the identification of the conserved gamete fusion factor generative cell specific 1/hapless 2 (GCS1/HAP2). GCS1 was first identified as a pollen generative cell-specific transmembrane protein in the lily (Lilium longiflorum), and was then shown to function not only in flowering plant gamete fusion but also in various eukaryotes, including unicellular protists and metazoans. In addition, although initially restricted to Chlamydomonas, knowledge of gamete attachment in flowering plants was also acquired. This review focuses on recent progress in the study of gamete interaction in volvocine green algae and flowering plants and discusses conserved mechanisms of gamete recognition, attachment, and fusion leading to zygote formation.
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Affiliation(s)
- Toshiyuki Mori
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Hiroko Kawai-Toyooka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tomoko Igawa
- Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo, Chiba 271-8510, Japan
| | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
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