イノベーション創出院
南予水産研究センター
Update date:2025/02/03
Associate Professor
Saito Taiju

Affiliation

  1. Ehime UniversityInstitution for Collaborative Relations, South Ehime Fisheries Research CenterAssociate Professor

Research History

  1. 2004/04-2008/07Hokkaido UniversityFaculty of Fisheries SciencesAcademic Fellow
  2. 2008/08-2010/03Purdue UniversityThe Department of Animal SciencePostdoctoral research associate
  3. 2010/09-2012/03Hokkaido UniversityField Science Center for Northern BiospherePostdoctoral fellow
  4. 2012/04-2015/05University of South Bohemia in CBFaculty of Fisheries and Protection of WatersResearch Scientist
  5. 2015/06-2021/08Ehime UniversitySouth Ehime Fisheries Research CenterSpecially-Appointed Associate Professor
  6. 2021/09-presentEhime UniversitySouth Ehime Fisheries Research CenterAssociate Professor

Education

  1. Tokai University1995/04/011999/03/25graduated
  2. Tokai University1999/04/012001/03/25completed
  3. Hokkaido University2001/04/012004/03/25completed

Degree

  1. PhDFisheries ScienceHokkaido University2004/03/24

Current State of Research and Teaching Activities

「魚類の借腹生産」は、有用系統・有用種・絶滅危惧種の生殖細胞を取り出し、より育てやすい宿主魚に移植することで、効率的な配偶子生産を目指す技術です。この技術を確立・実用化することを目指し、北海道大学、米国パデュー大学、チェコ共和国南ボヘミア大学と場所を変えながら、長年研究を行ってきました。顕微注入などの胚操作技法や胚発生過程の観察など、魚卵の扱いに関して経験豊富です。これまでは特に、胚発生期に生じる始原生殖細胞(すべての生殖細胞の元になる細胞)に興味を持ち、得られた知見から、生殖細胞の移植技術を開発しました。

現在は、南予水産研究センターでマグロ類スマの養殖研究を行っています。当然スマでも借腹生産を目指して研究を行っていますが、スマ養殖に本気で向き合うほど、「基礎から応用まで」の幅広い研究が必要であると痛感しています。

現在以下のような研究に取り組んでいます。
1)紫外線による魚類の不妊化手法の開発
3)スマ筋肉の「味」に関する基礎的研究
4)魚類の借腹生産技術開発
5)チョウザメ胚をモデルとした発生学的研究
など
cultured kawakawa Visualized PGCs in an embryo
cultured kawakawa Visualized PGCs in an embryo

Research Areas

  1. Aquaculture, Germ Cells, Fish Breeding

Research Interests

  1. Germline chimera
  2. Surrogate production
  3. Primordial germ cell
  4. breeding
  5. Sterilization
  6. Aquaculture
  7. transplantation
  8. Ecological Developmental Biology
  9. Aquaculture
  10. Germ cells transplantation
  11. Primordial Germ cell
  12. Chimera
  13. 顕微操作
  14. Embryonic Development
  15. 魚類発生工学

Research Projects

  1. 【受託研究費】愛南町における新魚種養殖魚開発に係る研究開発2022/04-2023/03Other南予地域に適した新養殖魚の開発を行う。
  2. 紫外線照射による海産魚分離浮性卵の不妊化誘導Grant-in-Aid for Scientific Research (B)2021/04-2025/03Principal investigator
  3. 【受託研究費】新規養殖魚等の研究開発2021/04-2022/03Coinvestigator(s)
  4. Development of the "competent-embryo" that possess the cells up-taking ability.Grant-in-Aid for Challenging Research (Exploratory)2017/06-2020/03Principal investigator
  5. Development of host strains for the production of gametes through germline chimera in marine fishGrant-in-Aid for Scientific Research (B)2017/04-2021/03Principal investigator

Books and Other Publications

  1. Forefront of the science of palatability and food tech斎藤大樹 近藤総一郎 松原孝博 後藤理恵第15章 官能評価と味認識装置によるスマの味解析シーエムシー出版2022/089784781316758
  2. Vertebrate Embryogenesis, Methods in Molecular BiologyTaiju Saito Rie Goto Nicola Rivers Etsuro YamahaProduction of germ-line chimeras in zebrafishHumana Press, New York, NY2019/029781493990085
  3. Microinjection. Methods in Molecular BiologyRie Goto Taiju Saito Takahiro Matsubara Etsuro YamahaMicroinjection of Marine Fish EggsHumana Press, New York, NY2018/109781493988303
  4. 実験医学別冊 ラボ必携 フローサイトメトリーQ&A斎藤大樹 後藤理恵Q96 非リンパ球、魚類胚由来の細胞など、とてもダメージに弱いデリケートな細胞をダメージレスセルソーターでソーティングしたいと考えています。メリット、デメリット、ソーティングの実際を教えて下さい。羊土社2017/114758122350

Papers

  1. Intracytoplasmic sperm injection in sturgeon species: A promising reproductive technology of selected genitors2022/12/23Effrosyni Fatira Miloš Havelka Taiju Saito José Landeira Marek Rodina David Gela Martin PšeničkaFrontiers in Veterinary Science9Research paper (scientific journal)10.3389/fvets.2022.1054345URLFrontiers Media SASturgeons are the most endangered species group and their wild populations continue to decrease. In this study, we apply intracytoplasmic sperm injection (ICSI), an assisted reproductive technology, for the first time in endangered and critically endangered sturgeons. Using various egg-sperm species combinations we performed different ICSI experiments with immobilized pre- or non-activated spermatozoa, single or many, fresh or cryopreserved. Then we evaluated the fertilization success as well as the paternity of the resultant embryos and larvae. Surprisingly, all experimental groups exhibited embryonic development. Normal-shaped feeding larvae produced in all egg-sperm species-combination groups after ICSI using single fresh-stripped non-activated spermatozoa, in one group after ICSI using single fresh-stripped pre-activated spermatozoa, and in one group after ICSI using multiple fresh-stripped spermatozoa. ICSI with single cryopreserved non-activated spermatozoa produced neurula stage embryos. Molecular analysis showed genome integration of both egg- and sperm-donor species in most of the ICSI transplants. Overall, ICSI technology could be used as an assisted reproduction technique for producing sturgeons to rescue valuable paternal genomes.
  2. Efficient Artificial Fertilization and Ovulated Egg Preservation in Kawakawa Euthynnus affinis2022/04/28Mitsuru Endoh Ryuji Hazama Keita Kaya Yusuke Futamura Sakurako Doi Izumi Makinose Dipak Pandey Osamu Nishimiya Miloš Havelka Taiju Saito Rie Goto Takahiro MatsubaraJournal of Marine Science and Engineering10/ 5, 599-599Research paper (scientific journal)10.3390/jmse10050599URLMDPI AGArtificial fertilization of cultured fish is essential for seed production using breeding techniques. However, in tuna species, the success rate of artificial fertilization is tremendously low. In this study, it was reported that the adequate procedure for ovulated egg collection and storage for artificial fertilization in kawakawa Euthynnus affinis. The collection of ovulated eggs was attempted using new techniques that disrupt only spawning activity without discontinuing ovulation. The available time to use ovulated eggs was also examined by assessing the optimal preservation process and temperature. As a result, artificial fertilization was effectively executed by assessing spawning time and thoroughly extracting ovulated eggs immediately after ovulation, with a success rate of 70% and an ovulation rate of 51.7%. Ovulated eggs could be stored with small quantities of ovarian fluid to sustain fertility. However, fertility was better preserved with Hanks’ solution. Ovulated eggs with high productivity were achieved 3 h after egg extraction when maintained in Hanks’ solution at 20 °C, leading to a supply of one-cell stage embryo for microinjection treatment constantly by continuously executing artificial fertilization. This systematic procedure permitted selective breeding by 1:1 mating between top-quality parental fish and applying several developmental engineering techniques to kawakawa breeding.
  3. Blastomeres derived from the vegetal pole provide extra-embryonic nutrition to sturgeon (Acipenser) embryos: Transition from holoblastic to meroblastic cleavage2022/03Mujahid Ali Shah Effrosyni Fatira Viktoriia Iegorova Xuan Xie David Gela Marek Rodina Roman Franěk Martin Pšenička Taiju SaitoAquaculture551, 737899-737899Research paper (scientific journal)10.1016/j.aquaculture.2022.737899Elsevier BV
  4. TALEN-Mediated Gene Editing of slc24a5 (Solute Carrier Family 24, Member 5) in Kawakawa, Euthynnus affinis2021/12/04Dipak Pandey Takahiro Matsubara Taiju Saito Yukinori Kazeto Koichiro Gen Tetsushi Sakuma Takashi Yamamoto Miyuki Mekuchi Rie GotoJournal of Marine Science and Engineering9/ 12, 1378-1378Research paper (scientific journal)10.3390/jmse9121378URLMDPI AGTranscription activator-like effector (TALE) nucleases (TALENs) mediated gene editing methods are becoming popular and have revealed the staggering complexity of genome control during development. Here, we present a simple and efficient gene knockout using TALENs in kawakawa, Euthynnus affinis, using slc24a5. We examined slc24a5 gene expression and functional differences between two TALENs that hold the TALE scaffolds, +153/+47 and +136/+63 and target slc24a5. Developmental changes in slc24a5 transcripts were seen in early-stage embryos by real-time PCR; slc24a5 expression was first detected 48 h post fertilization (hpf), which increased dramatically at 72 hpf. Four TALENs, 47- and 63-type of two different target loci (A and B), respectively, were constructed using Platinum TALEN and evaluated in vitro by a single-strand annealing (SSA) assay. TALEN activities were further evaluated in vivo by injecting TALEN mRNAs in the two-cell stage of the zygote. Most of the TALEN-induced mutants showed mosaic patterns in the retinal pigment epithelium (RPE) and fewer melanin pigments on the body at 72 hpf and later when compared to the control, implying the gene’s association with melanin pigment formation. A heteroduplex mobility assay (HMA) and the genome sequence further confirmed the TALEN-induced mutations of substitution, insertion, and deletion at an endogenous locus.
  5. Chromosome-Scale Genome Assembly and Transcriptome Assembly of Kawakawa Euthynnus affinis; A Tuna-Like Species2021/09/20Miloš Havelka Eitaro Sawayama Taiju Saito Kazutoshi Yoshitake Daiki Saka Toshinao Ineno Shuichi Asakawa Motohiro Takagi Rie Goto Takahiro MatsubaraFrontiers in Genetics12, 739781-739781Research paper (scientific journal)10.3389/fgene.2021.739781URLFrontiers Media SA

Presentations

  1. Surrogate Production in FishWorkshop on Biotechnology in Aquatic Sciences2018/05/10Oral presentation(invited, special)
  2. Development of Priomordial Germ Cells and Pigment Cells in Eastern Little Tuna, Euthynnus affinis, Embryos.6th International Workshop on the Biology of Fish Gametes2017/09/05Oral presentation(invited, special)

Allotted Class

  1. 2024Advanced Study on Hydrosphere Production Science
  2. 2024Advanced Study on Hydrosphere Production Science
  3. 2024Advanced Training of Fieldworks
  4. 2024Advanced Training of Fieldworks
  5. 2024Aquaculture

Media Coverage

  1. 幻の魚「スマ」を身近に…研究チームの努力「養殖技術で高品質を」InternetAbema Times2022/04/15養殖魚の解説
  2. 幻の魚「スマ」を身近に…研究チームの努力「養殖技術で高品質を」InternetYahoo! ニュース2022/04/15
  3. メディア出演InternetAbemaAbemaヒルズ2022/04/15養殖魚に関する解説

Committee Memberships

  1. 2021/10-presentInternational symposium on reproduction in aquatic animals (REPROAQUA-2022)Scientific and Advisory Board