後藤 彩子 (ゴトウ アヤコ)
GOTOH Ayako
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職名 |
准教授 |
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学位 |
農学(愛媛大学), 理学(東京大学), 理学(東京都立大学) |
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専門分野 |
アリ、精子貯蔵メカニズム、受精嚢、昆虫機能 |
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ホームページ |
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外部リンク |
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出身大学院 【 表示 ／ 非表示 】
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愛媛大学 連合農学研究科 生物環境保全学専攻 博士課程 修了
2004年4月 - 2008年2月
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東京大学 理学系研究科 生物科学専攻 修士課程 修了
2002年4月 - 2004年3月
学外略歴 【 表示 ／ 非表示 】
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独立行政法人日本学術振興会
2011年4月 - 2013年3月
国名：日本国
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自然科学研究機構生理学研究所
2010年9月 - 2011年3月
国名：日本国
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自然科学研究機構基礎生物学研究所
2008年4月 - 2010年8月
国名：日本国
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独立行政法人日本学術振興会
2005年4月 - 2007年3月
国名：日本国
論文 【 表示 ／ 非表示 】
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Whole-genome sequencing of the ant Crematogaster osakensis (Hymenoptera: Formicidae: Myrmicinae). 査読あり 国際誌
Ayako Gotoh, Atsushi Toyoda, Takahiro Yamabe, Takehiko Itoh
DNA research : an international journal for rapid publication of reports on genes and genomes 32 ( 3 ) 2025年5月
担当区分：筆頭著者, 責任著者
The ant Crematogaster osakensis (Hymenoptera: Formicidae: Myrmicinae) serves as a valuable model organism for investigating queen-specific traits, such as reproductive capacity and longevity, at the cellular and molecular levels. To support future research on queen traits using molecular techniques, including genome editing and multi-omics data analyses, we performed whole-genome sequencing of this species. The genome size of C. osakensis was estimated to be 284 Mb, with a heterozygosity of 0.26%. Annotation revealed the presence of 16,053 protein-coding genes. Furthermore, using the coding sequences annotated in this study, we reanalyzed previously obtained transcriptome data to identify highly expressed genes in the reproductive organs of queens and males. This data will contribute to a deeper understanding of the genetic mechanisms underlying reproductive strategies in ants.
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Establishment of a rapid, cost-effective, and accurate method for assessing insect sperm viability. 査読あり 国際誌
Mika Takeshima, Ayako Gotoh
Journal of insect physiology 104682 - 104682 2024年7月
担当区分：最終著者, 責任著者
High-quality sperm cells are crucial to reproductive success for both males and post-mating females in animals. Sperm viability, defined as the proportion of viable sperm cells, is used as a sperm quality index and this method has provided new insights into research on reproductive strategies. However, current staining protocols could potentially underestimate viability due to cell damage caused by cell treatments such as high dye concentration and long time for post-mounting. In this study, we established a method that enables rapid sperm viability assessment, has low sperm cell toxicity, and provides precise results regardless of operator expertise, and cost-effective using sperm cells from an ant, Crematogaster osakensis (Hymenoptera). First, to shorten the time for observation of a sufficient number of sperm cells, the volume per field of view was increased by height elevation between the glass slide and the coverslip, thereby we increased the number of sperm cells in a field of view. Second, to reduce sperm cell toxicity, we optimized the minimum dye concentration and incubation time using acridine orange (AO) and Hoechst in addition to SYBR14 and propidium iodide (PI), which has been used in most previous studies. We determined the optimal protocol to be 1 µg/mL AO and 150 µM PI without incubation. Besides, we automated counting sperm cells with ImageJ software and combined with manual correction for more accurate results. We employed the improved method for sperm samples from mealworm beetles (Tenebrio molitor) and silkmoths (Bombyx mori). This method, established through our study, will advance research on reproductive strategies, including sperm competition and sperm quality maintenance in females.
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Ayako Gotoh
Molecular Reproduction and Development 91 ( 2 ) 2024年2月
担当区分：筆頭著者, 最終著者, 責任著者 出版者・発行元：Wiley
Abstract
Ant queens can maintain a large number of sperm cells for over a decade after mating at the beginning of their adult lives until they die. This sperm storage ability is prominent; however, the cellular mechanisms involved remain unclear. Sperm cells are maintained in the female sperm storage organ—the spermatheca—which supplies a suitable environment for sperm cells. To reveal the molecular basis of the long‐term sperm storage mechanisms in ant queens, protein profiles enriched in the spermathecal fluid relative to the hemolymph were identified in Lasius japonicus using data‐independent acquisition‐based quantitative proteomics technology. Proteins related to the extracellular matrix, antioxidants, metabolic pathways, proteases, chaperones, and with uncharacterized functions were especially abundant with higher log ratio values in the spermathecal fluid relative to the hemolymph. These enriched proteins were shared with highly expressed genes previously detected by transcriptome analyses of the spermatheca in queens of Crematogaster osakensis that belong to a different subfamily than L. japonicus. It is likely that the ability for long‐term sperm storage evolved early in the ant lineage. Therefore, the common proteins identified in these two ant species are possibly crucial for this ability.DOI： 10.1002/mrd.23733
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Evolution of meconium removal from cocoons in ants 査読あり
A. Gotoh, F. Ito, R. Mizuno, Y. Shimamoto, K. Kinomura, E. Katsura, R. Hashim
Insectes Sociaux 2023年8月
共著
担当区分：筆頭著者, 責任著者 出版者・発行元：Springer Science and Business Media LLC
Ants exhibit an ancestral trait in which larvae spin silk and cover themselves; however, this trait has been secondarily lost in many subfamilies, genera, and species. The cocoon state should be linked to hygiene strategies for immatures; therefore, it is crucial to understand the diversity of this state. Based on our observations and previous literature, we reported that an unusual cocoon trait, which lacks the posterior end of the cocoon, including the meconium (intestinal contents purged by larvae), evolved sporadically in 28 species belonging to the subfamilies Amblyoponinae, Ponerinae, Myrmeciinae, Ectatomminae, and Formicinae. Furthermore, we observed that meconium-removing behavior by workers.
DOI： 10.1007/s00040-023-00926-3
その他リンク： https://link.springer.com/article/10.1007/s00040-023-00926-3/fulltext.html
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Near-anoxia induces immobilization and sustains viability of sperm stored in ant queens 査読あり
Ayako Gotoh, Mika Takeshima, Ken-ichi Mizutani
Scientific Reports 13 ( 1 ) 2023年3月
担当区分：筆頭著者, 責任著者 出版者・発行元：Springer Science and Business Media LLC
Abstract
After copulation, insect females store sperm in a spermatheca for some duration until fertilization. At the beginning of their adult lives, ant queens can preserve numerous viable sperm cells from copulation for over ten years. However, the key factors influencing long-term sperm storage have not been identified. Here we show that the spermathecal environment is nearly anoxic, which induces sperm immobilization. Furthermore, mitochondrial respiratory inhibitors suppress sperm motility, suggesting that sperm immobilization may be caused by a shortage of ATP generated from only glycolysis under near-anoxic conditions. Sperm immobilization is not induced by acidification via glycolytic metabolism because the spermathecal fluid is not acidic. Finally, we show that artificial anoxic conditions rather than aerobic conditions sustain viable sperm cells. Therefore, near-anoxia is a key factor influencing long-term sperm storage in ant queens. The viability of sperm cells under artificial anoxia, however, is lower than that of those dissected immediately from queens. Moreover, the immotile sperm cells under more than 4 h of anoxia do not begin swimming after aerobic exposure, unlike those under anoxic conditions for less than 2 h. This finding indicates that factors other than anoxia are also necessary for long-term sperm preservation.
総説・解説記事（Misc） 【 表示 ／ 非表示 】
科研費（文科省・学振）獲得実績 【 表示 ／ 非表示 】
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女王アリの長期間の精子貯蔵に関わる受精嚢内微小環境の解析
2020年4月 - 2023年3月
学術振興機構 科学研究費助成事業 基盤研究(C)
後藤 彩子
社会性ハチ目昆虫では、女王は羽化後まもない時期にしか交尾しないため、この時に受け取った精子を体内の受精嚢の中に寿命が続く限り貯蔵する。本研究では、精子が貯蔵される微小空間である受精嚢リザーバー内の化学的な性質を調べた後、それらのどの因子が精子の生存に寄与するか、また、寄与するのであれば 具体的に精子の生理状態にどのように影響しているかを明らかにすることで、アリ科女王の長期間の精子貯蔵メカニズムの解明を目指している。 本年度は、微量な受精嚢リザーバー内液をサンプリングし、プロテオーム解析をすることに成功した。解析の結果、精子貯蔵に重要だと思われるタンパク質候補を絞り込むことができた。また、これまでに、貯蔵中の精子は不動化されていることがわかっている(Gotoh and Furukawa, 2018)。昨年度に各種試薬や阻害剤を使用することで、精子の不動化に関与する要素をほぼ特定することができたが、本年度ではそれをさらに補強するデータがとれた。これらのデータをまとめ、現在論文を執筆している。
研究費にかかる研究（調査）活動報告書 【 表示 ／ 非表示 】
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2023年度 女王アリの長期間にわたる精子貯蔵メカニズムとその進化
研究費の種類： その他
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2022年度 女王アリの長期間にわたる精子貯蔵メカニズムとその進化
研究費の種類： その他
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2021年度 女王アリの長期間にわたる精子貯蔵メカニズムとその進化
研究費の種類： その他
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2020年度 女王アリの長期間にわたる精子貯蔵メカニズムとその進化
研究費の種類： その他