Leydig Cells Express Follicle-Stimulating Hormone Receptors in African Catfish

Abstract

This report aimed to establish, using African catfish, Clarias gariepinus, as model species, a basis for understanding a well-known, although not yet clarified, feature of male fish reproductive physiology: the strong steroidogenic activity of FSHs. Assays with gonadotropin receptor-expressing cell lines showed that FSH activated its cognate receptor (FSHR) with an at least 1000-fold lower EC50 than when challenging the LH receptor (LHR), whereas LH stimulated both receptors with similar EC50s. In androgen release bioassays, FSH elicited a significant response at lower concentrations than those required to cross-activate of the LHR, indicating that FSH stimulated steroid release via FSHR-dependent mechanisms. LHR/FSHR-mediated stimulation of androgen release was completely abolished by H-89, a specific protein kinase A inhibitor, pointing to the cAMP/protein kinase A pathway as the main route for both LH- and FSH-stimulated steroid release. Localization studies showed that intratubular Sertoli cells express FSHR mRNA, whereas, as reported for the first time in a vertebrate, catfish Leydig cells express both LHR and FSHR mRNA. Testicular FSHR and LHR mRNA expression increased gradually during pubertal development. FSHR, but not LHR, transcript levels continued to rise between completion of the first wave of spermatogenesis at about 7 months and full maturity at about 12 months of age, which was associated with a previously recorded approximately 3-fold increase in the steroid production capacity per unit testis weight. Taken together, our data strongly suggest that the steroidogenic potency of FSH can be explained by its direct trophic action on FSHR-expressing Leydig cells.

Sertoli cell proliferation in the adult testis is induced by unilateral gonadectomy in African catfish

“…Irrespective of the mechanism(s) involved, our This has been shown in Japanese eel [31], African catfish [17], and zebrafish [18]. Indeed, Fsh was 23 more potent as steroidogenic hormone than Lh in both catfish [60] and zebrafish [18].…”

“…[7] and the three gonadotropin subunits (lhb, fshb, cga) [37,59], and the testicular and seminal 7 vesicle mRNA levels of the Lh receptor (lhcgr) [58] and the Fsh receptor (fshr) [6], using the ∆∆Ct 8 method. A detailed description of the rtqPCR procedure has been given previously [6,17]. Primers 9 and fluorogenic probes (Table 1), specific for the mRNAs mentioned above, or for the endogenous 10 control (catfish 28s rRNA), were designed with Primer Express software (Applied Biosystems, Foster…”

Fsh and Lh have common and distinct effects on gene expression in rainbow trout testis

“…The presence of Fshr has been described in the tubular compartment but also on Leydig cells in four species so far, i.e. eel, African catfish, zebrafish, and honeycomb grouper (Ohta et al 2007, Garcia-Lopez et al 2009, Alam et al 2010. These studies have suggested that the steroidogenic potency of Fsh may result from the direct action of Fsh on Leydig cells.…”

Effect of purwoceng Pimpinella alpina extract mixed into the feed on spermatogenesis male catfish Clarias sp.

“…fed diet supplemeted with purwoceng extract kelenjar utama yang mengatur reproduksi dan spermatogenesis secara umum. Melalui sistem ini, gonadotropin pituitari, LH dan FSH mengatur testis melalui reseptor yaitu LH reseptor dan FSH reseptor (García-López et al, 2009;Schulz et al, 2008). Deteksi imunositokemikal protein reseptor FSH pada Anguilla japonica, sel Leydig, menandakan bahwa peran FSH pada spermatogenesis diatur oleh produksi androgen (Ohta et al, 2007).…”