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Shiba Y, Takahashi T, Ohashi Y, Ueda M, Mimuro A, Sugimoto J, Noguchi Y, Igawa T. Behavior of Male Gamete Fusogen GCS1/HAP2 and the Regulation in Arabidopsis Double Fertilization. Biomolecules 2023; 13:biom13020208. [PMID: 36830580 PMCID: PMC9953686 DOI: 10.3390/biom13020208] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Revised: 01/16/2023] [Accepted: 01/18/2023] [Indexed: 01/25/2023] Open
Abstract
In the sexual reproduction of flowering plants, two independent fertilization events occur almost simultaneously: two identical sperm cells fuse with either the egg cell or the central cell, resulting in embryo and endosperm development to produce a seed. GCS1/HAP2 is a sperm cell membrane protein essential for plasma membrane fusion with both female gametes. Other sperm membrane proteins, DMP8 and DMP9, are more important for egg cell fertilization than that of the central cell, suggesting its regulatory mechanism in GCS1/HAP2-driving gamete membrane fusion. To assess the GCS1/HAP2 regulatory cascade in the double fertilization system of flowering plants, we produced Arabidopsis transgenic lines expressing different GCS1/HAP2 variants and evaluated the fertilization in vivo. The fertilization pattern observed in GCS1_RNAi transgenic plants implied that sperm cells over the amount of GCS1/HAP2 required for fusion on their surface could facilitate membrane fusion with both female gametes. The cytological analysis of the dmp8dmp9 sperm cell arrested alone in an embryo sac supported GCS1/HAP2 distribution on the sperm surface. Furthermore, the fertilization failures with both female gametes were caused by GCS1/HAP2 secretion from the egg cell. These results provided a possible scenario of GCS1/HAP2 regulation, showing a potential scheme for capturing additional GCS1/HAP2-interacting proteins.
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Affiliation(s)
- Yuka Shiba
- Graduate School of Horticulture, Chiba University, Matsudo 648, Matsudo-shi 271-8510, Japan
| | - Taro Takahashi
- Graduate School of Horticulture, Chiba University, Matsudo 648, Matsudo-shi 271-8510, Japan
| | - Yukino Ohashi
- Graduate School of Horticulture, Chiba University, Matsudo 648, Matsudo-shi 271-8510, Japan
| | - Minako Ueda
- Graduate School of Life Sciences, Department of Ecological Developmental Adaptability Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
- Suntory Rising Stars Encouragement Program in Life Sciences (SunRiSE), Sendai 980-8578, Japan
| | - Amane Mimuro
- Graduate School of Horticulture, Chiba University, Matsudo 648, Matsudo-shi 271-8510, Japan
| | - Jin Sugimoto
- Graduate School of Horticulture, Chiba University, Matsudo 648, Matsudo-shi 271-8510, Japan
| | - Yuka Noguchi
- Graduate School of Horticulture, Chiba University, Matsudo 648, Matsudo-shi 271-8510, Japan
| | - Tomoko Igawa
- Graduate School of Horticulture, Chiba University, Matsudo 648, Matsudo-shi 271-8510, Japan
- Plant Molecular Science Center, Chiba University, 1-33 Yayoi, Chiba-shi 263-8522, Japan
- Correspondence:
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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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