Synthesis of sex steroids in final oocyte maturation and induced ovulation in female Eurasian perch, Perca fluviatilis

Abstract

This study was designed to specify the testosterone (T), estradiol-17b (E 2) and 17,20b-dihydroxy-4-pregnen-3-one (17,20b-P) variations during the pre-ovulatory period in female Eurasian perch, Perca fluviatilis, and also examine the ovarian synthesis of 17,20b-P and 17,20b,21-trihydroxy-4-pregnen-3-one (20b-S). Five females (100-300 g) were collected from a concrete pond from the Lindre Center (Moselle, France) between March and April 1999, three times a week, and sex steroids measured. Two females were also collected from the Lindre pond on three dates (18 February, 14 and 23 March) for an in vitro study. Significant plasma 17,20b-P peaks were measured for the first time in this species reaching 3.5 ng ml-1. However, the synthesis and release of 17,20b-P in blood seems to not be synchronized with the final maturation and ovulation stages. The in vitro study showed that ovaries at the pre-ovulatory stage produce some 17,20b-P but no 20b-S from a tritiated precursor (17-P-3 H). 17,20b-P is produced after 30 min and is still present in the medium after 2 h of incubation, but is no longer detectable after 4 h. Some other non-identified compounds were synthesized at this stage suggesting that 17,20b-P was quickly metabolized. Moreover, the plasma level increases, observed in spawned females suggest that this steroid might be involved in the oviposition process. These results suggest a role for 17,20b-P in the final stages of oocyte development.

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“…The gonadosomatic index in wild fish (26.9±4.4%) corresponded to the results published by Migaud et al (2003). These values were significantly higher than in farmed fish (18.5±2.3%), also similar to results in farmed fish recorded by Migaud et al, (2002).…”

“…However, in our study, ovarian development was not synchronous among fish, and this could explain that spawning period depended on the high variability steroid concentrations (Ciereszko et al, 1997a(Ciereszko et al, , 1997bMigaud et al, 2003).…”

A new classification of pre-ovulatory oocyte maturation stages in pikeperch, Sander lucioperca (L.), and its application during artificial reproduction

“…In this paper, the process is reflected in the positive correlation between oocyte maturation stage (according to our classification) and oocyte diameter. The weight increase in the Eurasian perch (during FOM alone) can reach 11% (Migaud et al . 2003; D. Żarski, Z. Bokor, L. Kotrik, B. Urbanyi, A. Horvath, K. Targońska and D. Kucharczyk unpublished).…”

“…Zakęś & Demska‐Zakęś 2009). For many fish species, including pikeperch and Eurasian perch, this classification is insufficient to describe the changes that occur during the FOM (Migaud, Mandiki, Gardeur, Fostier, Kestemont & Fontaine 2003; Migaud, Fontaine, Kestemont, Wang & Brun‐Bellut 2004; Kucharczyk et al . 2007).…”

Arachidonic Acid Induces Production of 17,20β‐Dihydroxy‐4‐pregnen‐3‐one (DHP) via a Putative PGE2 Receptor in Fish Follicles from the Eurasian Perch

“…Vitellogenesis plays an important role in follicle growth and is estradiol-dependent, while the process of follicle maturation is characterized by the initiation of meiosis, migration, and breakdown of the germinal vesicle (GVBD), coalescence of lipid droplets and yolk globules in the cytoplasm, a rapid size increase of the follicle caused by hydration which is accompanied by an overall increase in follicle translucency [1]. In Eurasian perch, DHP seems to be the main steroid involved in the control of this final follicle maturation [23,24]. Among the tested fatty acids tested in the present study, only ARA seemed to be able to participate in DHP production in vitro in Eurasian perch.…”