Influence of epidermal growth factor supplementation during in vitro maturation on nuclear status and gene expression of canine oocytes.
ABSTRACT This study evaluated the effect of epidermal growth factor (EGF) supplementation during in vitro maturation on the meiotic status and the expression of EGF receptor (EGFr), luteinizing hormone receptor (LHr) and gap junction protein α 5 (GJA5) in canine cumulus-oocyte-complexes (COCs). COCs of ≥110 μm diameter, exhibiting dark pigmentation and completely surrounded by three or more layers of cumulus cells collected from anestrus stage ovaries in natural cycle were matured in TCM-199 supplemented with 10% fetal bovine serum, 0.57 mM cysteine, 10 μg/ml LH and FSH, and different concentrations of EGF (0, 10 and 30 ng/ml). Oocytes cultured for 72 h were fixed to assess the nuclear maturation. Expression of EGFr, LHr and GAJ5 was assessed by immunocytochemistry and real-time PCR. Proportion of metaphase II status of oocytes cultured in in vitro maturation (IVM) medium supplemented with 10 ng/ml EGF for 72 h was significantly (P<0.05) higher than 0 and 30 ng/ml EGF supplemented IVM medium (9.8% vs. 6.5% and 5.2%). In both cumulus cells and oocytes, EGFr protein was undetectable, LHr protein level of expression was low and a strong expression of GJA5 protein was observed. The relative abundance (RA) of EGFr transcript revealed low levels and the LHr expression decreased steadily with addition of EGF. However it did not vary among different concentrations of EGF supplementation. The RA of GJA5 transcript exhibited lower level at 10 ng/ml EGF supplementation. In conclusion, the supplementation of 10 ng/ml EGF in IVM media exerted a positive influence on the progression of maturation to MII phase and the expression level of GJA5 at 72 h, but did not demonstrate any stimulatory role on the expression of EGFr and LHr during the maturation of the canine IVM oocytes.
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ABSTRACT: The mitogenic effects of epidermal growth factor (EGF) and fibroblast growth factor (FGF) on cultured granulosa cells of different species have been analyzed. EGF and FGF are potent mitogenic agents for rabbit, porcine, and human granulosa cell cultures. While guinea pig granulosa cell cultures respond to FGF, they were hardly effected by EGF. Rat granulosa cell cultures did not respond markedly to either EGF or FGF. Our results, therefore, demonstrate that the mitogenic effects of EGF and FGF are not restricted to granulosa cells of bovine origin and, with the exception of rat granulosa cells, cultured granulosa cells responded either to FGF alone or to both EGF and FGF with a marked increase in their rates of proliferation.Endocrinology 04/1979; 104(3):757-64. · 4.72 Impact Factor
- Journal of Small Animal Practice 08/1971; 12(7):383-9. · 1.18 Impact Factor
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ABSTRACT: Intercellular communication between granulosa cells and mouse oocytes has been examined during oocyte growth in vivo and in vitro. Intercellular communication, as assessed by transfer of fluorescein dye from oocytes to surrounding granulosa cells and metabolic cooperativity between the two cell types, existed throughout the period of oocyte growth examined (mean oocyte diameter increased from about 45 to about 65 μm). The extent of metabolic cooperativity for radiolabeled 2-deoxyglucose increased during oocyte growth in vivo and in vitro as a linear function of oocyte surface area. The extent of 2-deoxyglucose metabolic cooperativity between granulosa cells and oocytes of similar size was a linear function of the number of attached granulosa cells. Thus, the increase in the extent of metabolic cooperativity for 2-deoxyglucose during oocyte growth was probably due to formation of additional heterologous gap junctions between oocytes and new granulosa cells which come into contact with the growing oocyte. The rate of oocyte growth in vitro was positively correlated with the extent of 2-deoxyglucose metabolic cooperativity. A nutritional role for intercellular communication between granulosa cells and the oocyte in oocyte growth is discussed.Developmental Biology 04/1982; 90(1):144-53. · 3.87 Impact Factor