sábado, 29 de marzo de 2014

Nuestro último artículo, aceptado en Aquaculture

Effect of thermal regime on fatty acid dynamics in male European eels (Anguilla anguilla) during hormonally-induced spermatogenesis
R. Baeza, I. Mazzeo, M.C. Vílchez, V. Gallego, D.S. Peñaranda, L. Pérez, J.F. Asturiano

Little is known about the role of fat and fatty acids in European eel spermatogenesis. The aim of this work was to study the changes in fat content and to carry out a quantitative analysis of the fatty acid composition of the muscle, liver and gonad of European male eels throughout hormonally induced sexual maturation. The experiment was carried out under three different thermal regimes (two of them variable: T10 and T15; and one constant: T20) to replicate the changes of temperature that these fish undergo during their transoceanic reproductive migration. The European eel reached spermatogenesis earlier in treatment T20, suggesting that spermatogenesis in this species is closely regulated by water temperature. Although eels lose body mass due to the period of fasting that accompanies gonadal growth, no significant changes were found in the fat and fatty acid content of the muscle during the experimental period.
With regards to the liver, the levels of palmitic, eicosapentaenoic (EPA) and docosahexaenoic (DHA) acids increased significantly at the start of the spermiation process in all the thermal treatments.

In the testis, EPA, arachidonic acid (ARA) and DHA remained constant during the maturation process while the levels of the rest of the fatty acids decreased significantly. The stability of ARA and EPA levels in the testis may have a physiological significance, whereas the stability of DHA levels may have a structural one. The results suggest that the advancement of spermiation is influenced by water temperature and demonstrate the importance of the roles of EPA, ARA and DHA in European eel reproduction. This study makes it clear that complementary studies focusing on lipid composition of commercial diets could improve sperm quality in this species.

jueves, 27 de marzo de 2014

La Acción COST AQUAGAMETE financiará 14 nuevas estancias

La Acción COST AQUAGAMETE financiará 14 nuevas estancias (Short Term Scientific Missions) durante los últimos tres meses de su primer periodo (Marzo 2013-Mayo 2014), llegando así a un total de 31 estancias financiadas.

Los investigadores implicados viajarán de Dinamarca a Francia (1); República Checa a Japón (1); Francia a España (1); Hungría a España (1); República Checa a Francia (3); República Checa a España (1); España a Portugal (1); España a Eslovenia (1); España a Francia (1); Israel a Francia (1); Portugal a Italia (1); y Serbia a Hungría (1).

Buen viaje y mucho éxito a todos!

martes, 25 de marzo de 2014

Nuestro último artículo, aceptado en Reproduction in Domestic Animals

The regulation of aromatase and androgen receptor expression during gonad development in male and female European eel

D.S. Peñaranda, I. Mazzeo, V. Gallego, J. Hildahl, R. Nourizadeh-Lillabadi, L. Pérez, F.-A. Weltzien, J.F. Asturiano

This research investigated the regulation of aromatase and androgen receptor gene expression in the brain-pituitary-gonad (BPG) axis of male and female European eels (Anguilla anguilla) during induced sexual maturation. Complete Anguilla anguilla aromatase (aa-cyp19a1) and partial androgen receptor α and β (aa-ara and aa-arb) sequences were isolated, and qPCR assays were validated and used for quantification of transcript levels for these three genes. Expression levels of the genes varied with sex, tissue, and stage of maturation. aa-arb was expressed at higher levels than aa-ara in the pituitary and gonad in both sexes, suggesting aa-arb is the physiologically most important androgen receptor in these tissues. In the female brain, a decrease in aa-ara and an increase in aa-cyp19a1 were observed at the vitellogenic stage. In contrast, a progressive increase in all three genes was observed in the pituitary and ovaries throughout gonadal development, with aa-arb and aa-cyp19a1 reaching significantly higher levels at the vitellogenic stage. In the male pituitary, a decrease in aa-arb and an increase in aa-cyp19a1 were observed at the beginning of spermatogenesis, and thereafter remained low and high, respectively. In the testis, the transcript levels of androgen receptors and aa-cyp19a1 were higher during the early stages of spermatogenesis and decreased thereafter. These sex-dependent differences in the regulation of the expression of aa-ara, aa-arb, and cyp19a1 are discussed in relation to the role of androgens and their potential aromatization in the European eel during gonadal maturation.