Effects of Estradiol and Testosterone on the Expression of Growth‐related Genes in Female and Male Nile Tilapia, Oreochromis niloticus

Abstract

Nile tilapia exhibits strong sexual growth dimorphism. The potential role of sex steroid hormones in sexual growth dimorphism is not fully understood. We investigated the effects of estradiol (E 2 ) and testosterone (T) on growth rate, plasma sex hormones, and expression of growth hormone (GH)-insulin-like growth factor (IGF) axis genes and muscle regulatory factor (MRF) genes in female and male Nile tilapia. The results revealed that serum concentrations of E 2 and T were significantly higher after correlative injection (P < 0.05). Compared to male fish, female fish had lower growth rates. E 2 increased growth performance in females with no significant effects on males, whereas T significantly increased growth performance in males, with no significant effects on females. In females, E 2 significantly increased expression of ghr1, ghr2, igf1, and igf2, while T decreased igf2 and increased ghr1 and ghr2 expression. In males, T increased expression of igf1, igf2, ghr1, and ghr2, and E 2 decreased expression of igf1, ghr1, and ghr2. Additionally, E 2 (myod1, myod2, myog, and myf5) in female and male fish, respectively. The results suggest that sex steroid hormones play a role in sexual growth dimorphism by regulating the expression of GH-IGF axis and MRF genes. and T enhanced the expression of MRF genes

Comparative Physiological and Transcriptomic Profiling Offers Insight into the Sexual Dimorphism of Hepatic Metabolism in Size-Dimorphic Spotted Scat (Scatophagus argus)

“…In agreement with these previous reports, here we also observed a direct relationship between sex steroids and growth performance in S. argus . Furthermore, there are a number of examples in which treatments with sex steroids have been demonstrated to disparately affect the growth efficiency of fish [ 48 , 49 , 50 , 51 ]. Specifically, androgenic steroids generally stimulate growth in fish species exhibiting male-biased SSD, while estrogenic steroids mainly have growth-promoting effects on fish species showing female-biased SSD [ 50 , 51 ].…”

“…In female and male fish, sex steroid hormones are present in different concentrations and have different physiological effects. Along with their regulatory roles in fish reproduction, sex steroids have also been known to modulate other important biological processes like food intake, utilization of nutrients, energy metabolism and allocation, and stress response [ 47 , 51 , 52 , 53 ], exerting sex-dependent effects on somatic growth and thereby leading to the occurrence of SSD. These findings provide a valuable clue to reveal the mechanisms involved in sexual growth difference.…”

“…In fish species, recent investigations focusing on the neuroendocrine growth factors have characterized the sexual expression patterns of growth hormone-releasing hormone ( ghrh ) [ 7 , 8 ], growth hormone ( gh ) [ 9 , 10 , 11 , 12 ], growth hormone receptors [ 13 , 14 ], and insulin-like growth factor I ( igf1 ) [ 10 , 12 , 14 ]. Moreover, further understanding of the regulatory effects of sex hormones on GH/IGFs axis genes implies that these genes serve as key regulators in the occurrence of SSD [ 13 , 14 , 15 , 16 , 17 ].…”

High-Resolution Characterization of Male Ornamentation and Reevaluation of Sex Linkage in Guppies

“…Indeed, the extensive variation exhibited in total ornament area among natural [34] and introduced [33] populations hints at a simple genetic architecture, as the alternative of rapid and repeated movement of many underlying genes to the relatively small Y chromosome, is somewhat improbable. Given the importance of testosterone level and sensitivity in fish growth rates, maturation and colouration [67][68][69], and the variation observed in natural guppy populations in these traits [70], it is likely that testosterone and/or testosterone sensitivity vary across populations, and this may interact with colouration. The nature of these interactions, and the identification of the loci responsible for these Y-linked effects remain interesting areas of future research.…”

Estudio de la perturbación del desarrollo sexual de Cnesterodon decemmaculatus (Pisces, Poeciliidae) por compuestos con actividad estrogénica

“… Inhibición de la liberación de gonadotrofinas desde la hipófisis (Kordon y Gaillard, 2006;Waye y Trudeau, 2011).  Interferencia con la producción de hormonas esteroideas gonadales (Kester et al, 2000;Yue et al, 2018).…”