Efeito de Diferentes Concentrações de Oxigênio Sobre o Cultivo In Vitro de Folículos Pré-Antrais Caprinos. / Effect of Different Concentrations of Oxygen About In Vitro Cultivation of primordial follicles Goats.

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

07/12/2009

RESUMO

The aim of the present study was to evaluate the effect of two different oxygen (O2) concentrations on the survival and development of goat preantral follicles cultured in vitro. Preantral ovarian follicles (150 μm) were isolated from ovarian cortex fragments and individually cultured for 30 days under two different O2 concentrations (5% and 20%). Follicle development was evaluated on the basis of antral cavity formation, increase in follicular diameter, presence of healthy cumulus oocyte complexes and fully grown oocytes. Viability of follicles classified as live through the morphological evaluation was confirmed using fluorescent markers. Oocytes and granulosa cells were considered live if the cytoplasm was stained positively with calcein-AM (green) and if chromatin was not labeled with ethidium homodimer-1 (red). Data from follicular survival, antrum formation and meiotic resumption after in vitro culture were compared by the Chi-square test. Follicular diameter and growth rate after culture were compared by use of the Kruskal-Wallis non-parametric test. Results showed that with progression of culture period from 6 to 12 days, a decrease in follicular survival was observed in both O2 concentrations (P<0.05). When the O2 tensions were compared to each other in the different days of culture, 20% O2 was more efficient in promoting an increase in follicular diameter from day 24 of culture onwards than 5% O2 (P<0.05). However, follicles cultured with 5% O2 had an increased percentage of antrum formation from day 12 to the end of culture, as compared with 20% O2 (P<0.05). Moreover, there were no differences in the percentage of fully developed oocytes with the different O2 tensions. It is important to emphasize that16.7% of oocytes from follicles cultured in 20% O2 resumed meiosis. In conclusion, the concentration of 20% O2 was more efficient in promoting follicular growth and oocyte meiosis resumption from preantral follicles of goats when grown in vitro.

ASSUNTO(S)

caprino oxigênio folículos pré-antrais cultivo reproducao animal goat oxygen preantral follicles culture

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