Molecular cloning, characterization expression of P450c17-I and P450c17-II and their functions analysis during the reproductive cycle in males of barfin flounder (Verasper moseri)

Abstract

P450c17, a key steroidogenic enzyme, plays important roles in the production of sex steroid and cortisol. In teleost, there are two types of P450c17, P450c17-I possessing 17α-hydroxylase and 17, 20-lyase activities, and P450c17-II only possessing 17α-hydroxylase activity. This work describes the molecular cloning of the cDNA encoding the barfin flounder (Verasper moseri) P450c17-I and P450c17-II by means of RT-PCR and 5' and 3' rapid amplification of cDNA ends (RACE) analyses and mRNA expression profiles analyzing by semiquantitative RT-PCR. Respectively, P450c17-I and P450c17-II mRNA levels in the testes correlated with serum testosterone (T) level, as well as gonadosomatic index (GSI) of males during specific stages of spermatogenesis. P450c17-I and P450c17-II mRNA were expressed in the testis and ovary, suggesting that both of them participate in the production of sex steroid in barfin flounder gonads. P450c17-I mRNA was undetectable; in contrast, P450c17-II mRNA was detected at the highest level in the head kidney, meaning that only P450c17-II is involved in the production of cortisol in barfin flounder. The results demonstrated that both of P450c17-I and P450c17-II participate in the production of sex steroid in male barfin flounder gonads.

Large-scale tissue-specific and temporal gene expression profiles in Pengze crucian carp

“…Moreover, Pcc-cyp11a1 and Pcc-star transcripts were significantly higher in hepatopancreas, muscle, and spleen tissues. cyp17a1 transcripts were found in gonads of medaka, tilapia, zebrafish, and barfin flounder (Jin et al, 2012), and transcripts were also found in brain and gonadal tissues of half-smooth tongue-sole (Chen et al, 2010) and in both kidney and gonad tissues of Korean rockfish (Mu et al, 2013). cyp17a1 was found to be a key factor associated with mature oocyte cells, and Pcc-cyp17a1 transcripts were only found in ovary, hepatopancreas, eye, and gill tissues in the present study, which demonstrated that steroidogenic genes were involved in gonadal development of gynogenic Pcc-zp, a female-specific gene associated with ovarian development, was present in ovary tissues before being transported to hepatopancreas tissue (Modig et al, 2006), which contains hepatic-specific and ovarian-specific expression patterns (Wu et al, 2012).…”

Cyp17a2 is involved in testicular development and fertility in male Nile tilapia, Oreochromis niloticus

“…In contrast, duplicated cyp17a genes, i.e. cyp17a1 and cyp17a2 , were isolated from the genomes of several teleosts and suspected to synergistically catalyzing the synthesis of C18, C19 and C21 steroid hormones ( 20 – 22 ). Previous reports revealed that cyp17a1 gene mutation ceased both androgens and estrogens production, and caused spermiation disorder, infertility and all-male population production ( 23 – 25 ).…”

Polymorphism in exons CpG rich regions of the cyp17-II gene affecting its mRNA expression and reproductive endocrine levels in female Japanese flounder (Paralichthys olivaceus)

“…It is reported that P450c17-II is responsible for the production of 17a, 20b-dihydroxy-4-pregnen-3-one during oocyte maturation and cortisol production in the head kidney of Tilapias [48]. In barfin flounder (Verasper moseri),only P450c17-II is involved in the production of cortisol [16].…”