Yuya Hasegawa

Mr. Yuya Hasegawa


Research Focus & Metrics

Academic Career Length

5Years (2022-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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Verified
Journal Article
Open access
PDF file
RSRyohei Surugaya
Ryohei Surugaya
YHYuya Hasegawa
Yuya Hasegawa
SAShinji Adachi
Shinji Adachi
SIShigeho Ijiri
Shigeho Ijiri
The luteinizing hormone (LH) and maturation-inducing steroids (MIS), such as 17α,20β-dihydroxy-4-pregnen-3-one, regulate the final oocyte maturation in teleosts. Oocyte maturational competence (OMC) and ovulatory competence measure the sensitivity to MIS for oocyte maturation and ovulation, respectively. However, the molecular mechanisms underlying the acquisition of ovulatory competence remain unknown. Sturgeons are an excellent research model for investigating these mechanisms. We examined the seasonal profiles of OMC and ovulatory competence in vitro and the expression of 17 ovulation-related gene candidates using quantitative PCR in Amur sturgeon ovarian follicles. The ovulatory competence was induced by the LH-releasing hormone analog (LHRHa) priming injection after acquiring the OMC, which was spontaneously induced in spring or autumn. Seven genes, including the tissue-type plasminogen activator (plat), were enhanced following the LHRHa priming injection in ovarian follicles sampled from anovulated and ovulated fish. The activin receptor type 1 (acvr1) and prostaglandin G/H synthase 2 (ptgs2) were only upregulated in ovulated fish. Our results suggest that plat/plasmin and prostaglandin (PG)/PG receptor systems are essential for sturgeon ovulation, similar to other vertebrates. Notably, successful ovulation depends on a sufficient PG synthesis, and mediators activating the PG/PG receptor system are essential for acquiring the ovulatory competence. We provide the first report of ovulation-related gene alterations in the ovarian follicles of Amur sturgeons.

19 December 2023 in The Journal of Steroid Biochemistry and Molecular Biology
Verified
Journal Article
Closed access
YHYuya Hasegawa
Yuya Hasegawa
RSRyohei Surugaya
Ryohei Surugaya
TTTousaka Tousaka
Tousaka Tousaka
SAShinji Adachi
Shinji Adachi
SIShigeho Ijiri
Shigeho Ijiri

1 November 2023 in Fisheries Science
Verified
Journal Article
Closed access
PDF file
RSRyohei Surugaya
Ryohei Surugaya
YHYuya Hasegawa
Yuya Hasegawa
TTTousaka Tousaka
Tousaka Tousaka
SAShinji Adachi
Shinji Adachi
SIShigeho Ijiri
Shigeho Ijiri