Expression profile of star and cyp19 and plasma sex steroid during gonad development from previtellogenesis to early atresia in captive Sterlet sturgeon,Acipenser ruthenus

Abstract

Summary The aromatase cytochrome P450 family 19 (cyp19a) and Steroidogenic acute regulatory protein (star) mRNA levels were investigated in the ovarian follicles of captive Sterlet sturgeon, Acipenser ruthenus by real‐time PCR, and also plasma sex steroid levels and cortisol were measured throughout oogenesis from previtellogenic (PV) to early atresia. Thirty two females divided into four groups including PV, vitellogenic (VTG), post‐vitellogenic (POV) and atresia by histological studies. Blood samples were captured by heparinized syringes and gonad tissue samples were taken via a non‐lethal biopsy. Expression levels of both cyp19a and star transcripts were affected by gonadal development stage. Total cyp19a and star ovarian transcripts were markedly up‐regulated at VTG and POV Sterlet sturgeon, respectively. Significant elevation of sex steroids includes 17β estradiol (E2) and testosterones (T) were found during gonadal development progression, followed by steroid concentrations decrease at follicular atresia. However, plasma cortisol levels decreased during oogenesis. A positive correlation observed between plasma E2 and T with star mRNA expression. These results reveal a strong relationship between expressions of steroidogenesis related gene with gonadal development. Therefore, it seems that these genes affect estrogen synthesis and the physiological balance among the sex steroid hormones throughout oocyte development in Sterlet sturgeon.

Theoretical Analysis and Expression Profiling of 17β-Hydroxysteroid Dehydrogenase Genes in Gonadal Development and Steroidogenesis of Leopard Coral Grouper (Plectropomus leopardus)

“…The gender of fish exhibits significant plasticity, being influenced not only by genetic factors but also potentially by certain intrinsic or extrinsic factors, particularly sex steroids [22]. Hsd17b enzymes play a crucial role in the biosynthesis of sex steroids, acting downstream in the hormone synthesis pathway and involved in the interconversion of E1, E2, A, and T [19].…”

“…Currently, the synthesis and metabolism pathway of sex steroid hormones in fish is a hot research topic. However, related research primarily focuses on the aromatase gene cyp19a [22] and some genes in the steroid hormone synthesis pathway, such as StAR2 [23] and cyp11a [24]. Research on the Hsd17b family genes has been mainly concentrated in mammals, where their expression levels and genotypes are closely associated with various diseases [25].…”

The Important Role of Sex-Related Sox Family Genes in the Sex Reversal of the Chinese Soft-Shelled Turtle (Pelodiscus sinensis)

“…Sex steroid hormones, especially androgen and E 2 , play an important regulatory role in reproductive activities such as sex determination, gametogenesis, and storage in turtles and other vertebrates [ 45 , 46 , 47 ]. In the gonadal transcriptome of P. sinensis , cyp19a1 , cyp11a , hsd3b , hsd11b2 , and hsd17b7 were found to be significantly enriched in steroid hormone biosynthesis and ovarian steroid hormone genesis pathways.…”

“…In the gonadal transcriptome of P. sinensis , cyp19a1 , cyp11a , hsd3b , hsd11b2 , and hsd17b7 were found to be significantly enriched in steroid hormone biosynthesis and ovarian steroid hormone genesis pathways. Previous studies have shown that star , cyp11a1 , and hsd3b are closely related to gonadal development and gametogenesis in fish [ 45 , 48 , 49 ]. Hsd11b2 is involved in the synthesis of androgen 11-kT, and it plays an important role in the male sex differentiation of vertebrates such as Epinephelus coioides [ 50 ] and Cynoglossus semilaevis [ 51 ].…”