Granulocyte-macrophage colony stimulating factor (GM-CSF) enhances cumulus cell expansion in bovine oocytes
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Date
Authors
BERLAND OLEA, MARCO ANTONIO
Peralta, Oscar A.
Bucher, Danai
Fernandez, Ana
Berland, Marco
Strobel, Pablo
Ramirez, Alfredo
Ratto, Marcelo H.
Concha, Ilona
Peralta, Oscar A.
Bucher, Danai
Fernandez, Ana
Berland, Marco
Strobel, Pablo
Ramirez, Alfredo
Ratto, Marcelo H.
Concha, Ilona
Authors
Date
Datos de publicación:
10.1186/1477-7827-11-55
Keywords
GM-CSF - Oocyte maturation - Embryo development - GM-CSF receptors
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Abstract
Background: The objectives of the study were to characterize the expression of the alpha- and beta-subunits of granulocyte-macrophage colony stimulating factor (GM-CSF) receptor in bovine cumulus cells and oocytes and to determine the effect of exogenous GM-CSF on cumulus cells expansion, oocyte maturation, IGF-2 transcript expression and subsequent competence for embryonic development. Methods: Cumulus-oocyte complexes (COC) were obtained by aspirating follicles 3- to 8-mm in diameter with an 18 G needle connected to a vacuum pump at -50 mmHg. Samples of cumulus cells and oocytes were used to detect GM-CSF receptor by immunofluorescence. A dose-response experiment was performed to estimate the effect of GM-CSF on cumulus cell expansion and nuclear/cytoplasmic maturation. Also, the effect of GM-CSF on IGF-2 expression was evaluated in oocytes and cumulus cells after in vitro maturation by Q-PCR. Finally, a batch of COC was randomly assigned to in vitro maturation media consisting of: 1) synthetic oviductal fluid (SOF, n = 212); 2) synthetic oviductal fluid supplemented with 100 ng/ml of GM-CSF (SOF + GM-CSF, n = 224) or 3) tissue culture medium (TCM 199, n = 216) and then subsequently in vitro fertilized and cultured for 9 days. Results: Immunoreactivity for both alpha and beta GM-CSF receptors was localized in the cytoplasm of both cumulus cells and oocytes. Oocytes in vitro matured either with 10 or 100 ng/ml of GM-CSF presented a higher (P < 0.05) cumulus cells expansion than that of the control group (0 ng/ml of GM-CSF). GM-CSF did not affect the proportion of oocytes in metaphase II, cortical granules dispersion and IGF-2 expression. COC exposed to 100 ng/ml of GM-CSF during maturation did not display significant differences in terms of embryo cleavage rate (50.4% vs. 57.5%), blastocyst development at day 7 (31.9% vs. 28.7%) and at day 9 (17.4% vs. 17.9%) compared to untreated control (SOF alone, P = 0.2). Conclusions: GM-CSF enhanced cumulus cell expansion of in vitro matured bovine COC. However, GM-CSF did not increase oocyte nuclear or cytoplasmic maturation rates, IGF-2 expression or subsequent embryonic development.
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Keywords
GM-CSF , Oocyte maturation , Embryo development , GM-CSF receptors
Citation
10.1186/1477-7827-11-55