Structure-activity relationships of C21 steroids in an in vitro oocyte maturation bioassay in rainbow trout, Salmo gairdneri

17α-Hydroxy-20β-dihydroprogesterone and 17α-hydroxyprogesterone were found in higher concentrations in serum from female Salmo gairdneri undergoing final oocyte maturation immediately before ovulation than in serum from spermiating male trout. Other steroids (11-deoxycorticosterone, 11-deoxycortisol and progesterone) which have been implicated in oocyte maturation and/or ovulation in lower vertebrates were not identified at such high concentrations and the differences between the serum of both sexes were not so great. These results confirm that 17α-hydroxy-20β-dihydroprogesterone and 17α-hydroxyprogesterone, the most potent inducers of trout oocyte maturation in vitro, are present in the blood when oocyte maturation occurs. The concentration of testosterone was found to be higher in serum from female than from male trout indicating that testosterone is unlikely to be the principal androgen in trout. High concentrations of 11-oxotestosterone in male and barely detectable levels in female fish support the hypothesis that 11-oxotestosterone is an important androgen in the regulation of testicular activity.

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Agonistic effect of imidazole and triazole fungicides on in vitro oocyte maturation in rainbow trout (Oncorhynchus mykiss)

Marine Environmental Research ◽

10.1016/j.marenvres.2004.03.008 ◽

2004 ◽

Vol 58 (2-5) ◽

pp. 143-146 ◽

Cited By ~ 11

Author(s):

Gilles Monod ◽

Hélène Rime ◽

Julien Bobe ◽

Bernard Jalabert

Keyword(s):

Rainbow Trout ◽

Oncorhynchus Mykiss ◽

Oocyte Maturation ◽

Triazole Fungicides ◽

Rainbow Trout Oncorhynchus Mykiss ◽

In Vitro Oocyte Maturation ◽

Agonistic Effect

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In Vitro Oocyte Maturation and Ovulation in Rainbow Trout (Salmo gairdneri), Northern Pike (Esox lucius), and Goldfish (Carassius auratus)

Journal of the Fisheries Research Board of Canada ◽

10.1139/f76-124 ◽

1976 ◽

Vol 33 (4) ◽

pp. 974-988 ◽

Cited By ~ 212

Author(s):

Bernard Jalabert

Keyword(s):

Oocyte Maturation ◽

Sensu Stricto ◽

Salmo Gairdneri ◽

Follicular Maturation ◽

Goldfish Carassius Auratus ◽

Control Oocyte ◽

Follicle Maturation ◽

Ovulatory Process ◽

Matured Oocyte

The endocrine processes which control oocyte maturation (resumption of meiosis) and ovulation have been studied in vitro in the trout Salmo gairdneri. Follicular maturation is ultimately under the control of a pituitary gonadotropin which induces the follicle to synthesize specific steroids; these steroids act in turn directly on the oocyte to promote maturation. The systematic study of the in vitro efficiency of various steroids have shown that 17α-hydroxy-20β-dihydroprogesterone plays a preferential role in initiating maturation; this steroid has a high affinity for a plasma protein system. The efficiency of this steroid, similarly to the efficiency of the gonadotropin, can be modulated by other circulating steroids. The precise chronology of some events of follicle maturation have been defined using inhibitors of protein and RNA synthesis.The ovulatory process (sensu stricto: expulsion of matured oocyte from the follicular envelopes) has been experimentally dissociated from oocyte maturation, and some mediators likely to act on ovulation have been identified.These data permit the consideration of novel means of intervention at the ovarian level to synchronize maturation and ovulation in fish, in order to give new tools for progress in aquaculture.

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