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Parthenogenetic Activation of Pig Oocytes: RESULTS(2)

A23187-lnduced CG Exocytosis

CGs were evenly distributed in the cortex of the oocytes after maturation (Fig. 2a), with a mean number of 48.5 ± 15.5 CGs/100 |xm2. CG densities significantly decreased in A23187-treated oocytes (Table 1; Fig. 2, b and c). CG exocytosis was also induced by A23187 in a concentration-dependent manner with mean residual CG numbers of 31.3 ± 17.7 (representing 35.5% of CG exocytosis), 17.3 ± 22.6 (64.3%), 13.0 ± 6.6 (73.2%), and 12.3 ± 7.9 (74.6%)/100 |xm2 in the oocytes treated with 10, 25, 50, and 100 |xM A23187, respectively. When oocytes were treated in 5% DMSO for 5 min, the density of CGs was 44.3 ± 11.9/100 |xm2, which was not statistically different from that in oocytes maintained in medium alone without DMSO. buy ampicillin

Another difference in CG exocytosis was that global CG exocytosis was observed in oocytes treated with high concentrations (25-100 |xM) of A23187 (Fig. 2c), but uneven CG exocytosis was observed in oocytes treated with 10 ц.М A23187 (Fig. 2b).
TABLE 1.

ConcentrationA23187(j*.M) Ca2+ transient CG exocytosis Nuclear activation Zona pellucida dissolution time (sec)
No. of oocytes measured Peak ratio* No. of oocytes examined No. of CGs/100 ц,т2 of cortex % of CGs exocytosis3 No. of oocytes examined No. of activated oocytes (%)
0 (medium) ND* 28 48.5 ± 15.5 0b 71 0b 163.3 ± 5.8b
0 (DMSO) 3 1.28 ± 0.10b 27 44.3 ±11.9 8.6b 95 0b 216.7 ± 23.1b
10 4 1.61 ± 0.19′ 27 31.3 ± 17.7 35.5′ 97 18(19.8 ± 9.7)’ 205.0 ± 30.0b
25 4 2.23 ± 0.21d 29 17.3 ± 22.6 64.3d 100 39 (44.5 ± 21.3)d 241.7 ± 10.4′
50 4 2.60 ± 0.14е 18 13.0 ± 6.6 73.2d 89 44 (49.5 ± 12.4)de 251.7 ± 35.5′
100 4 3.35 ± 0.34f 44 12.3 ± 7.9 74.6d 98 60(62.3 ± 14.7)e 251.7 ± 16.1′

*    Oocytes (cultured for 44 h) were treated for 5 min and then cultured in mTBM for 3 h (for examination of CG exocytosis and zona dissolution time) and 12 h (for examination of nuclear activation). Experiments were repeated four times. The data were expressed as mean ± SD.
*    The highest value of calcium transients in the oocytes.
*    ND: not determined.