Circadian Changes in Serum Concentrations of Steroids in Japanese Char Salvelinus leucomaenis at the Stage of Final Maturation

Yamada, Hideaki; Satoh, Ri-Ichi; Ogoh, Masashi; Takaji, Keigo; Fujimoto, Yasufumi; Hakuba, Takeshi; Chiba, Hiroaki; Kambegawa, Akira; Iwata, Munehico

doi:10.2108/zsj.19.891

Cited by 53 publications

(26 citation statements)

References 33 publications

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“…In relation to the LD cycle, the acrophase of daily cortisol rhythms occurs at the early photophase in Gulf killifish (Fundulus grandis;Garcia & Meier 1973) and Mozambique tilapia (Oreochromis mossambicus; Nikaido et al 2010), at the beginning of the scotophase in sea bass (Planas et al 1990), tench (De Pedro et al 1998 and sole (Solea senegalensis; López-Olmeda et al 2013) and during the scotophase in brown trout (Salmo trutta; Pickering & Pottinger 1983) and Japanese char (Salvelinus leucomaenis; Yamada et al 2002). Two peaks in cortisol have been described in sea bass (Cerdá-Reverter et al 1998) and Atlantic salmon smolts (Ebbesson et al 2008).…”

Section: Glucocorticoidsmentioning

confidence: 99%

Interplay between the endocrine and circadian systems in fishes

Isorna

Pedro

Valenciano

et al. 2017

Journal of Endocrinology

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The circadian system is responsible for the temporal organisation of physiological functions which, in part, involves daily cycles of hormonal activity. In this review, we analyse the interplay between the circadian and endocrine systems in fishes. We first describe the current model of fish circadian system organisation and the basis of the molecular clockwork that enables different tissues to act as internal pacemakers. This system consists of a net of central and peripherally located oscillators and can be synchronised by the light-darkness and feeding-fasting cycles. We then focus on two central neuroendocrine transducers (melatonin and orexin) and three peripheral hormones (leptin, ghrelin and cortisol), which are involved in the synchronisation of the circadian system in mammals and/or energy status signalling. We review the role of each of these as overt rhythms (i.e. outputs of the circadian system) and, for the first time, as key internal temporal messengers that act as inputs for other endogenous oscillators. Based on acute changes in clock gene expression, we describe the currently accepted model of endogenous oscillator entrainment by the light-darkness cycle and propose a new model for non-photic (endocrine) entrainment, highlighting the importance of the bidirectional cross-talking between the endocrine and circadian systems in fishes. The flexibility of the fish circadian system combined with the absence of a master clock makes these vertebrates a very attractive model for studying communication among oscillators to drive functionally coordinated outputs.

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Section: Glucocorticoidsmentioning

confidence: 99%

Interplay between the endocrine and circadian systems in fishes

Isorna

Pedro

Valenciano

et al. 2017

Journal of Endocrinology

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“…The DHP in blood sera and media from the 20β-HSD activity assays were extracted, according to the method of Kagawa et al (22), and DHP concentrations were measured using time-resolved fluoroimmunoassay, according to the method of Yamada et al (23). DHP was purchased from Sigma Chemicals (St. Louis, MO, USA), and the FKA332 antibody for DHP was purchased from Cosmo-Bio Co., Ltd. (Tokyo, Japan).…”

Section: Dhp Quantificationmentioning

confidence: 99%

17β-HSD type 12-like is responsible for maturation-inducing hormone synthesis during oocyte maturation in masu salmon¹²

et al. 2016

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Abbreviated title: 17β-HSD12-like responsible for DHP production Key terms: 17α,20β-dihydroxy-4-pregnen-3-one, 20β-hydroxysteroid dehydrogenase, 17β-hydroxysteroid dehydrogenase, Oocyte maturation, Granulosa, Masu salmon, Oncorhynchus masou AbstractThe maturation-inducing hormone 17α,20β-dihydroxy-4-pregnen-3-one (DHP) was first identified in the amago salmon. However, although carbonyl reductase-like 20β-hydroxysteroid dehydrogenase (CR/20β-HSD) was reported to convert 17α-hydroxyprogesterone (17OHP) to DHP in rainbow trout, we previously found that CR/20β-HSD mRNA was not up-regulated in stimulated granulosa cells from masu salmon, which suggested that DHP is synthesized by a different enzyme. Accordingly, the present study aimed to identify the specific 20β-hydroxysteroid dehydrogenase (20β-HSD) responsible for DHP production by granulosa cells during final oocyte maturation in masu salmon. RNA-sequencing was performed on granulosa layers that were isolated from ovarian follicles at one month before ovulation and incubated with or without forskolin, which was used to mimic luteinizing hormone, and ~12 million reads were obtained, which yielded 71,062 contigs of > 100 bp. tBlastx analysis identified one contig (#f103496) as similar to 17β-hydroxysteroid dehydrogenase type 12 (hsd17β12); however, because the fulllength #f103496 sequence was different from hsd17β12, it was termed to hsd17β12-like (hsd17β12l). We found that mammalian cells transfected with full-length hsd17β12l exhibited considerable 20β-HSD activity, as indicated by efficient conversion of exogenous 17OHP to DHP. In addition, we found that hsd17β12l mRNA levels were consistently low in follicles during vitellogenic growth; however, the levels increased significantly during final oocyte maturation. The levels of hsd17β12l mRNA were also considerably increased in granulosa layers in which 20β-HSD activity was induced by salmon pituitary extract. Therefore, we suggest that hsd17β12l, not CR/20β-HSD, is the 20β-HSD responsible for DHP production by granulosa cells in masu salmon during final oocyte maturation.

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“…Blood samples were taken from the heart with a heparinized syringe and needle, centrifuged at 1,5009g, and plasma was stored at -20°C until measurement of 11-ketotestosterone (11-KT) levels. Plasma 11-KT levels were measured by time-resolved fluoroimmunoassay (TR-FIA) as described previously [19,20].…”

Section: Blood and Testes Samplingmentioning

confidence: 99%

Induction of spermatogenesis in Japanese eel by recombinant goldfish gonadotropins

Hayakawa¹,

Nagaya

Kaki

et al. 2008

Fish Sci

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We previously demonstrated the biological activities of single-chain recombinant gonadotropins (scGTHs) of goldfish Carrassius auratus follicle-stimulating hormone (scFSH) and luteinizing hormone (scLH), produced by a baculovirus-silkworm larvae system, by using in vivo bioassays with some fishes including Japanese eel Anguilla japonica. Among the bioassays, we succeeded in induction of spermatogenesis of sexually immature male Japanese eels by both scFSH and scLH, especially resulting in the occurrence of spermatozoa in scLH-administered males. However, those recombinant hormones did not induce enlargement of testes. In order to further confirm the potency of recombinant GTHs for use in aquaculture species, we administered scFSH and scLH to males of Japanese eel at higher dosage and frequency (eight times with 2-5 days interval) than those of the previous study (five or six times with 7 days intervals), including combination of scFSH and scLH administration (scFSH-scLH). Gonadosomatic indices (GSI) of scLH-and scFSH-scLH-administered males were larger than those of initial control males and of control males that were injected with saline. Enlargement of testes was also confirmed by measurement of testicular lobe size in scFSH-, scLH-, and scFSH-scLH-administered males. By histological observation, occurrence of spermatozoa was confirmed in scLH-and scFSH-scLH-administered eels. Although milt production was not induced, higher dosage and frequency of scGTH administration was effective in promoting testicular development of immature eels. Thus, single-chain fish GTHs produced by the baculovirus-silkworm larvae system could be a useful tool for promotion of gonadal maturation in aquaculture fishes.

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Circadian Changes in Serum Concentrations of Steroids in Japanese Char Salvelinus leucomaenis at the Stage of Final Maturation

Cited by 53 publications

References 33 publications

Interplay between the endocrine and circadian systems in fishes

Interplay between the endocrine and circadian systems in fishes

17β-HSD type 12-like is responsible for maturation-inducing hormone synthesis during oocyte maturation in masu salmon¹²

Induction of spermatogenesis in Japanese eel by recombinant goldfish gonadotropins

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Circadian Changes in Serum Concentrations of Steroids in Japanese Char Salvelinus leucomaenis at the Stage of Final Maturation

Cited by 53 publications

References 33 publications

Interplay between the endocrine and circadian systems in fishes

Interplay between the endocrine and circadian systems in fishes

17β-HSD type 12-like is responsible for maturation-inducing hormone synthesis during oocyte maturation in masu salmon12

Induction of spermatogenesis in Japanese eel by recombinant goldfish gonadotropins

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17β-HSD type 12-like is responsible for maturation-inducing hormone synthesis during oocyte maturation in masu salmon¹²