5α-Pregnane-3β,7α,17,20α- and -20β-tetrols as metabolites of progesterone and 17-hydroxyprogesterone in carp (Cyprinus carpio) ovarian incubations

General and Comparative Endocrinology843401-404GCEN

Steroid metabolism in teleost gonads: purification and identification of metabolites by high-performance liquid chromatography

Steroids576276-281STED

Steroid metabolism by ovarian follicles and extrafollicular tissue of the guppy (Poecilia reticulata) during oocyte growth and gestation

General and Comparative Endocrinology863378-394GCEN

Synthesis of 17,20α/β-dihydroxy-4-pregnen-3-one and 5β-pregnanes in spermatozoa of primary and 17α-methyltestosterone-induced secondary male grouper (Epinephelus coioides)

10.1006/gcen.1998.7122General and Comparative Endocrinology11211-9GCEN

Use of computer assisted sperm analysis (CASA) for monitoring the effects of pollution on sperm quality of fish: application to the effects of heavy metals

Computer assisted sperm analysis (CASA) has been used to analyse the effects of cadmium and zinc on the motility of fish sperm treated either for 24h after partial dilution in an extender, or during the final dilution step on the microscope stage during video recording. The progressive motility of catfish sperm, which was not affected by storage for 24h, was decreased after exposure to 100 ppm cadmium or 2000 ppm zinc in extender for 24h. Only 1000 ppm cadmium or 2000 ppm zinc had any effect on motility when added to sperm at the final dilution stage. These results suggest that concentrations of cadmium which have been found to be present in fish gonads as a result of bioaccumulation from the water or diet may decrease the motility of sperm during maturation or storage in the testis. Cadmium toxicity was significantly decreased in the presence of an equal amount of zinc, suggesting an equilibrium between zinc and cadmium at binding sites in the sperm. Computer assisted sperm analysis is shown for the first time to provide a rapid and quantitative measure of the effects of environmental pollutants on the quality of fish sperm. It is suggested that the methodology described may form the basis for a standard toxicity test to assess the potential hazards of environmental pollutants on reproduction

17alpha,20alpha-dihydroxy-4-pregnen-3-one, not its 20beta isomer, is produced from 17alpha-hydroxyprogesterone by spermatozoa of secondary male groupers (Epinephelus tauvina) derived from females implanted with 17alpha-methyltestosterone

Journal of Experimental Zoology2716462-465JEZO

Histological and immunohistochemical investigation on ovarian development and plasma estradiol levels in the swordfish (Xiphias gladius L.)

The paper reports a histological and immunohistochemical description of oocyte growth and ultrastructural aspects of zona radiata (ZR) formation as well as the relationship between plasma estradiol-17b‚ (E2) levels and ovarian development in swordfish (Xiphias gladius L.) from the Mediterranean Sea. Ovaries were inactive during March to mid April; maturation occurred during late April to June and spawning in June and July. Zona radiata formation starts, as Pas positive material, in oocytes at the lipid stage. In this stage a deposit of electrondense material between oolemma and follicular cells appears. In the cortical alveoli stage and through the early vitellogenic stage, the deposition of a moderately electrondense material occurred on the inner side of the ZR. Finally, in late vitellogenic oocytes a third layer, made of microfibrillar material, appeared. The immunohistochemical analyses revealed that the initial internalisation of hepatic zona radiata proteins (Zrp) in the swordfish oocyte starts before the uptake of vitellogenin (Vtg) and that it is associated with the low previtellogenic E2 plasma levels, while a significant E2 increase in plasma is associated with the beginning of Vtg uptake. This would appear to confirm the hypothesis that the differential and sequential induction of zonagenesis and vitellogenesis may reflect a general feature of teleost oogenesis