Multiple gonadotropin‐releasing hormone (GnRH)‐immunoreactive systems in the brain of the dwarf gourami,<i>Colisa lalia</i>: Immunohistochemistry and radioimmunoassay

Yamamoto, Naoyuki; Oka, Yoshitaka; Amano, Masafumi; Aida, Katsumi; Hasegawa, Yoshihisa; Kawashima, Seiichiro

doi:10.1002/cne.903550303

Cited by 121 publications

(138 citation statements)

References 68 publications

Supporting

Mentioning

131

Contrasting

Order By: Relevance

“…In fish, as in other vertebrates, several authors (e.g. Amano et al 1991, Grober et al 1994, Yamamoto et al 1995 have proposed the existence of at least two distinct GnRH neuronal systems. The cGnRH-II system predominates in the midbrain, while the second variant occurs in the pre-optic area.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Isolation and characterisation of mRNA encoding the salmon- and chicken-II type gonadotrophin-releasing hormones in the teleost fish Rutilus rutilus (Cyprinidae)

Penlington

Williams²,

Sumpter³

et al. 1997

Journal of Molecular Endocrinology

View full text Add to dashboard Cite

The complementary DNAs (cDNA) encoding the [Trp 7 ,Leu 8 ]-gonadotrophin-releasing hormone (salmon-type GnRH; sGnRH:GeneBank accession no. u60667) and the [His 5 ,Trp 7 ,Tyr 8 ]-GnRH (chicken-II-type GnRH; cGnRH-II: GeneBank accession no. u60668) precursor in the roach (Rutilus rutilus) were isolated and sequenced following reverse transcription and rapid amplification of cDNA ends (RACE). The sGnRH and cGnRH-II precursor cDNAs consisted of 439 and 628 bp, and included open reading frames of 282 and 255 bp respectively. The structures of the encoded peptides were the same as GnRHs previously identified in other vertebrates. The sGnRH and cGnRH-II precursor cDNAs, including the non-coding regions, had 88·6 and 79·9% identity respectively, to those identified in goldfish (Carassius auratus). However, significant similarity was not observed between the non-coding regions of the GnRH cDNAs of Cyprinidae and other fish. The presumed third exon, encoding partial sGnRH associated peptide (GAP) of roach, demonstrated significant nucleotide and amino acid similarity with the appropriate regions in the goldfish, but not with other species, and this may indicate functional differences of GAP between different families of fish. cGnRH-II precursor cDNAs from roach had relatively high nucleotide similarity across this GnRH variant. Cladistic analysis classified the sGnRH and cGnRH-II precursor cDNAs into three and two groups respectively. However, the divergence between nucleotide sequences within the sGnRH variant was greater than those encoding the cGnRH-II precursors. Consistent with the consensus developed from previous studies, Northern blot analysis demonstrated that expression of sGnRH and cGnRH-II was restricted to the olfactory bulbs and midbrain of roach respectively. This work forms the basis for further study on the mechanisms by which the tapeworm, Ligula intestinalis, interacts with the pituitary-gonadal axis of its fish host.

show abstract

Section: Introductionmentioning

confidence: 99%

“…Investigations of the GnRH innervation of the pituitary gland (e.g. Kah et al 1986, Amano et al 1991, Rosenblum et al 1994, Yamamoto et al 1995 suggested that, in fish, sGnRH may have a more important role to play in pituitary gland function than cGnRH-II.…”

Section: Introductionmentioning

confidence: 99%

Isolation and characterisation of mRNA encoding the salmon- and chicken-II type gonadotrophin-releasing hormones in the teleost fish Rutilus rutilus (Cyprinidae)

Penlington

Williams²,

Sumpter³

et al. 1997

Journal of Molecular Endocrinology

View full text Add to dashboard Cite

show abstract

“…21C), suggesting that sGnRH neurons in the OB and the TN are not involved in the regulation of gonadal maturation. In the dwarf gourami, GnRH originating from the TN does not affect GTH secretion but rather has a function as a neuromodulator in the brain (Oka and Ichikawa 1990;Oka 1992;Yamamoto et al 1995). sGnRH originating from the TN is also not considered to be essential for gonadal development in goldfish (Kobayashi et al , 1994Kim et al 2001).…”

Section: -2 Changes In Sgnrh Mrna Expression During Gonadal Maturatmentioning

confidence: 99%

Reproductive Biology of Salmoniform and Pleuronectiform Fishes with Special Reference to Gonadotropin-Releasing Hormone (GnRH)

Amano¹

2010

Aqua-BioSci. Monogr. (ABSM)

Self Cite

View full text Add to dashboard Cite

Keywords • GnRH AbstractA salmonid fish, masu salmon Oncorhynchus masou, has salmon gonadotropin-releasing hormone (sGnRH) and chicken GnRH-II (cGnRH-II), while a pleuronectiform fish, barfin flounder Verasper moseri, has sGnRH, cGnRH-II and seabream GnRH (sbGnRH). In masu salmon, sGnRH-immunoreactive (ir) cell bodies are scattered from the olfactory nerve through the ventral telencephalon (VT) and the preoptic area (POA). cGnRH-II-ir cell bodies are located in the midbrain tegmentum (MT). sGnRH but not cGnRH-II is detected in the pituitary. sGnRH peptide levels and sGnRH mRNA levels in the VT and the POA increased during gonadal maturation. sGnRH neurons are derived from the olfactory epithelium and migrate into the brain. In barfin flounder, sGnRH-ir, cGnRH-II-ir, and sbGnRH-ir cell bodies are located in the olfactory bulbs and the terminal nerve ganglion (TN), the MT, and the POA, respectively, and these neurons do not migrate in the brain. sbGnRH is detected in the pituitary. sbGnRH mRNA levels in the brain increased during gonadal maturation. Although three GnRH systems exist in the barfin flounder, anatomical distinction between the TN-and the POA-GnRH systems is not clear in masu salmon. Thus, it is suggested that sGnRH neurons in masu salmon play different roles according to the location in the brain. General introductionGonadotropin-releasing hormone (GnRH) is a decapeptide originally isolated from pig and sheep hypothalami as a physiologic regulator of luteinizing hormone (LH) release from the pituitary (Matsuo et al. 1971;Burgus et al. 1972). At present, it is generally accepted that GnRH regulates synthesis and release of pituitary gonadotropin (GTH) (see King and Millar 1992;Sherwood et al. 1993). It has been shown that two or three molecular forms of GnRH exist, even within the same species (Oka 1997;Okuzawa and Kobayashi 1999;Okubo and Nagahama 2008). In addition, GnRH can act as a neuromodulator and has also been implicated in reproductive behavior in many species including teleost fish such as dwarf gourami Colisa lalia (Yamamoto et al. 1997) and goldfish Carassius auratus (Volkoff and Peter 1999).To date, 15 forms of GnRHs have been identified based on their primary structure or complementary DNAs (cDNAs) in vertebrates, as shown in Fig. 1 (Okubo and Nagahama 2008;Kavanaugh et al. 2008). GnRH forms are traditionally named after the species from which they were first identified. In addition to vertebrate species, GnRH was isolated in invertebrates: e.g., in the protochordate Ciona intestinalis (Powell et al. 1996;Adams et al. 2003), octopus Octopus vulgaris (Iwakoshi et al. 2002) and the sea hare Aplysia californica (Zhang et al. 2008).In mammalian, avian, reptilian, and amphibian animals, GnRH is conveyed to the pituitary via the hypothalamo-hypophyseal portal vessels ( Fig. 2A). In mammals, pulsatile release of mammalian GnRH (mGnRH) by hypothalamic neurons stimulates GTH secretion from the pituitary. However, teleost fishes lack the median eminence. Instead, GnRH neurons are found to directly...

show abstract

“…1) (Oka and Matsushima, 1993;Kim et al, 1995;Yamamoto et al, 1995), indicating that the neural circuits of the olfactory bulb are major targets of neuromodulation by GnRH in these species. However, to date no published studies have examined the physiological effects of GnRH in the olfactory bulb; the data available at present only allow us to speculate on the possible neuromodulatory functions of GnRH in the olfactory bulb.…”

Section: Modulation In the Olfactory Bulbmentioning

confidence: 99%

Seasonal Variation in the Expression of Five Subtypes of Gonadotropin-releasing Hormone Receptor Genes in the Brain of Masu Salmon from Immaturity to Spawning

et al. 2005

View full text Add to dashboard Cite

Multiple gonadotropin‐releasing hormone (GnRH)‐immunoreactive systems in the brain of the dwarf gourami,Colisa lalia: Immunohistochemistry and radioimmunoassay

Cited by 121 publications

References 68 publications

Isolation and characterisation of mRNA encoding the salmon- and chicken-II type gonadotrophin-releasing hormones in the teleost fish Rutilus rutilus (Cyprinidae)

Isolation and characterisation of mRNA encoding the salmon- and chicken-II type gonadotrophin-releasing hormones in the teleost fish Rutilus rutilus (Cyprinidae)

Reproductive Biology of Salmoniform and Pleuronectiform Fishes with Special Reference to Gonadotropin-Releasing Hormone (GnRH)

Seasonal Variation in the Expression of Five Subtypes of Gonadotropin-releasing Hormone Receptor Genes in the Brain of Masu Salmon from Immaturity to Spawning

Contact Info

Product

Resources

About