Seasonal expression and cellular distribution of star and steroidogenic enzymes in quail testis

Abstract

The quail Coturnix coturnix is a seasonal breeder with a physiological switch on/off of gonadic activity. Photoperiod and temperature are the major environmental factors regulating the spermatogenesis. To more thoroughly comprehend the steroidogenic pathways that govern the seasonal reproductive cycle, we have investigated the localization of StAR protein and steroidogenic enzymes (3β‐HSD, 17β‐HSD, P450 aromatase, and 5α‐Red) as well as androgen and estrogen levels, in the testis of reproductive and nonreproductive quails. We demonstrated that StAR, 3β‐HSD, 17β‐HSD, P450 aromatase, and 5α‐Red were always present in the somatic (Leydig and Sertoli cells) and germ cells (spermatogonia, spermatocytes I and II, spermatids, and spermatozoa). In addition, by western blot analysis, we demonstrated that 17β‐HSD, P450 aromatase, and 5α‐Red showed the highest expression levels during the reproductive testis compared with nonreproductive one. Accordingly, we also found that during the reproductive phase the highest titres of testosterone, 17β‐estradiol, and 5α‐dihydrotestosterone are recorded. In conclusion, our findings demonstrated that in C. coturnix: (a) both somatic and germ cells are involved in the local synthesis of sex hormones; (b) 17β‐HSD, P450 aromatase, and 5α‐Red expressions, as well as testicular androgens and estrogens, increased in reproductive quail testis. This study strongly indicates that the steroidogenic process in quail testis exhibits seasonal changes with the promotion of both androgenic and estrogenic pathways in the reproductive period, suggesting their synergic mechanism in the spermatogenesis regulation.

Proliferative and Apoptotic Pathways in the Testis of Quail Coturnix coturnix during the Seasonal Reproductive Cycle

“…Several studies have reported ERα as the predominant form in quail testis [11,15,49], although there is no study on the seasonal pattern of ERα expression in the current literature. In line with our previous study, the present study demonstrated that quail testis exhibits the highest titers of E 2 during the reproductive period, when P450 aromatase, the enzyme that converts testosterone into E 2 , was expressed at the highest levels [35]. Accordingly, during this period, the levels of both cAMP and cGMP were increased.…”

“…Each testis from reproductive (n = 5) and non-reproductive (n = 5) quails were homogenized directly in lysis buffer containing 50 mM HEPES, 150 mM NaCl, 1 mM EDTA, 1 mM EGTA, 10% glycerol, 1% Triton X-100 (1:2 w/v), 1 mM phenylmethylsulphonyl fluoride (PMSF), 1 µg aprotinin, 0.5 mM sodium orthovanadate, and 20 mM sodium pyrophosphate, pH 7.4 (Sigma Chemical Corporation, St. Louis, MO, USA), then clarified by centrifugation at 14,000× g for 10 min [35]. Protein concentration was determined by the Bradford assay (Bio-Rad, Melville, NY, USA).…”

“…In this regard, the quail Coturnix coturnix represents an excellent avian model, as it demonstrates an annual cycle of testis size, sexual steroid production, and spermatogenesis [33][34][35]. A previous study by our research group revealed that in quail testis, the levels of both E 2 and androgens were higher during the reproductive period compared to the non-reproductive period, suggesting that estrogens act in synergy with androgens for the initiation of spermatogenesis [35]. Therefore, the present study was aimed to investigate the estrogen responsive system in quail testis in relation to reproduction seasonality.…”

Alkyphenol Exposure Alters Steroidogenesis in Male Lizard Podarcis siculus

“…For immunohistochemistry, poly-L -lysine slides (Menzel-Glaser, Braunschweig, Germany) with 5-µm thick sections were dewaxed, rehydrated in a graded series of alcohol, heat-treated (microwave) for 20 min in 10 mM citrate (pH 6.0) antigen-retrieval buffer, and then washed in PBS [49,50]. Briefly, to reduce endogenous peroxidase activity, sections were treated with 2.5% H 2 O 2 for 40 min at room temperature, and then blocked for 1 h at room temperature with normal goat serum (Pierce, Rockford, IL, USA).…”

E4 Transcription Factor 1 (E4F1) Regulates Sertoli Cell Proliferation and Fertility in Mice

“…From cell ablation studies, it has been recognized that the number of Sertoli cells determines testis size and daily sperm production [ 6 ]. Sertoli cells also influence testicular blood vessel architecture and secretion of testosterone and estrogen [ 7 , 8 , 9 ]. Therefore, revealing new insights into Sertoli cell biology is crucial for understanding animal spermatogenesis.…”