Biochemistry and physiology of fish gonadotropins

Swanson, Penny; Dickey, J. F.; Campbell, Barbara K.

doi:10.1023/b:fish.0000030476.73360.07

Cited by 254 publications

(151 citation statements)

References 53 publications

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“…Together, with thyrotropin (TSH) and chorionic gonadotropin (CG), GTHs are members of the glycoprotein hormone family and each member is a heterodimer consisting of two subunits termed a and b (Pierce & Parsons 1981, Suzuki et al 1988a, Swanson et al 2003. These heterodimeric glycoproteins are reported to carry highly conserved glycosylation sites, and the attached oligosaccharides are related to the hormone's biosynthesis, half-life, and biological activity both in fishes as well as in mammals (Ulloa-Aguirre et al 1999, Zenkevics et al 2000, Klein et al 2003.…”

Section: Introductionmentioning

confidence: 99%

Biological activities of recombinant Manchurian trout FSH and LH: their receptor specificity, steroidogenic and vitellogenic potencies

Ko¹,

Park²,

Kim³

et al. 2007

Journal of Molecular Endocrinology

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Gonadotropins (GTHs), FSH and LH, play central roles in vertebrate reproduction. Here, we report the production of biologically-active recombinant FSH (r-mtFSH) and LH (r-mtLH) of an endangered salmon species, Manchurian trout (Brachymystax lenok), by baculovirus in silkworm (Bombyx mori) larvae. The biological activities of the recombinant hormones were analyzed using COS-7 cell line transiently expressing either amago salmon FSH or LH receptor. The steroidogenic potency of the r-mtFSH and r-mtLH was examined by a culture system using rainbow trout follicles in vitro. In vivo, bioactivity was assessed by measuring ovarian weight, oocyte diameter, and plasma steroid hormone levels in female rainbow trout. Moreover, inducing potency of milt production were examined in vivo using goldfish. Our results demonstrated that the r-mtFSH and r-mtLH were successfully produced in the baculovirus-silkworm system and recognized by their cognate receptors specifically in vitro. The production of estradiol-17b (E2) and testosterone (T) was stimulated by the r-mtFSH and r-mtLH respectively, from the full-grown follicles of rainbow trout, whereas both E2 and T were increased by relatively higher doses of the recombinant hormones from the follicles of the maturing stage. In in vivo assay, injection of the r-mtFSH but not r-mtLH increased ovarian weight, oocyte diameter, and plasma E2 levels in immature rainbow trout. Injection of both r-mtFSH and r-mtLH induced milt production in male goldfish. In conclusion, the present study strongly suggests that the r-mtFSH and r-mtLH have distinct biological properties, such as a specific responsiveness for the cognate receptor, steroidogenic, and vitellogenic activities for ovarian follicles in salmonids. These recombinant FSH and LH may be applied for future studies on the gonadal development and maturation in fishes as well as the endangered salmon species.

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Section: Introductionmentioning

confidence: 99%

Biological activities of recombinant Manchurian trout FSH and LH: their receptor specificity, steroidogenic and vitellogenic potencies

Ko¹,

Park²,

Kim³

et al. 2007

Journal of Molecular Endocrinology

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“…Gonadotropins, follicle-stimulating hormone (FSH) and luteinizing hormone (LH), are the primary hormones governing gonadal development and function in vertebrates including teleosts (Gharib et al 1990, Swanson et al 2003, Weltzien et al 2004. Similar to those in mammals (Gharib et al 1990, Burger et al 2004, the secretion and expression of fish gonadotropins are controlled by both neuroendocrine factors from the hypothalamus such as gonadotropin-releasing hormone (GnRH; Peter et al 1986, Weltzien et al 2004, Ando & Urano 2005 and steroids from the gonads (Kobayashi et al 1987, Dickey & Swanson 1998.…”

Section: Introductionmentioning

confidence: 99%

Evidence for the existence of a local activin–follistatin negative feedback loop in the goldfish pituitary and its regulation by activin and gonadal steroids

Cheng¹,

Yuen²,

Ge³

2007

Journal of Endocrinology

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Activin is an important regulator of gonadotropin expression and production in the vertebrate pituitary, and its activity is fine-tuned by its binding protein follistatin. In the present study, a full-length cDNA for follistatin was cloned in the goldfish, which shows 74% amino acid sequence identity with that of mammals. Recombinant goldfish follistatin expressed in the Chinese hamster ovary cells significantly blocked activin-induced F5-5 cell differentiation. Goldfish follistatin is expressed in a wide range of tissues including the brain, pituitary, ovary, and testis. The expression of follistatin mRNA in the pituitary is regulated by both activin and gonadal steroids in vitro. Treatment with goldfish activin B for 48 h significantly up-regulated follistatin expression in cultured pituitary cells, suggesting a closed activin-follistatin feedback loop in the pituitary. In agreement with this, both human and goldfish follistatin down-regulated the expression of follistatin itself, probably due to the neutralization of endogenous activin. Examination of FSHb and LHb expression in the same samples supports the role of activin and follistatin in the differential regulation of FSH and LH as demonstrated previously. Since the expression level of activin b B in the pituitary is rather stable both in vitro and in vivo, it is conceivable that follistatin may play a pivotal regulatory role in the intra-pituitary activin system. Both estradiol and testosterone up-regulated follistatin expression in vitro, suggesting a mediating role for follistatin in steroid feedback on pituitary hormones. These results provide clues to the potential physiological roles of activin-follistatin system in the regulation of gonadotropin biosynthesis in teleosts.

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“…In Japanese eel (Anguilla japonica), 11-KT alone is capable of stimulating all stages of spermatogenesis (Miura et al 1991). In other species, particularly salmonids, the maturation of immature sperm is achieved through maturation-inducing hormone(s) (MIH) (Schulz et al 2001;Miura & Miura 2003;Swanson et al 2003). For many fish species, MIH has been identified as either a di-or trihydroxy derivative of progesterone (17α, 20β-dihydroxy-4-pregnen-3-one or 17α, 20β, 21-trihydroxy-4-pregnen-3-one) (Goetz 1983;Nagahama 1997;Yueh & Chang 1997;Ikeuchi et al 2001).…”

Section: Yellowfin Bream Acanthopagrus Australismentioning

confidence: 99%

Effect of gonadotropin releasing‐hormone analogue and human chorionic gonadotropin on milt characteristics and gonadal steroids in yellowfin bream,Acanthopagrus australis(Sparidae)

Black¹,

Pankhurst

2009

New Zealand Journal of Marine and Freshwater Research

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Adult yellowfin bream (Acanthopagrus australis) were captured from the wild and maintained in outdoor tanks until the onset of the natural spawning season (May -June). Three replicate trials were conducted to examine the effects of gonadotropin releasing-hormone analogue (GnRHa) and human chorionic gonadotropin (hCG) on milt characteristics and gonadal steroid levels. Spermiating males were injected intraperitoneally with either saline solution (control) or a single dose of GnRHa (25, 50, 75, 100 μg kg -1

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Biochemistry and physiology of fish gonadotropins

Cited by 254 publications

References 53 publications

Biological activities of recombinant Manchurian trout FSH and LH: their receptor specificity, steroidogenic and vitellogenic potencies

Biological activities of recombinant Manchurian trout FSH and LH: their receptor specificity, steroidogenic and vitellogenic potencies

Evidence for the existence of a local activin–follistatin negative feedback loop in the goldfish pituitary and its regulation by activin and gonadal steroids

Effect of gonadotropin releasing‐hormone analogue and human chorionic gonadotropin on milt characteristics and gonadal steroids in yellowfin bream,Acanthopagrus australis(Sparidae)

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