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ARS Home » Research » Publications at this Location » Publication #106985
Title: IMPROVING EFFICIENCY OF IN VITRO MATURED PIG OOCYTE ACTIVATION

Author
item ZHU, J - ROSLIN INSTITUTE
item DE SOUSA, P - ROSLIN INSTITUTE
item Dobrinsky, John
item TELFER, E - UNIVERSITY OF EDINBURGH
item WILMUT, I - ROSLIN INSTITUTE

Submitted to: The International Embryo Technology Society
Publication Type: Abstract Only
Publication Acceptance Date: 10/30/1999
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Although pig oocytes can be parthenogenetically activated, the rate of blastocyst formation is low. Four experiments were carried out to improve pig oocyte activation. After 37h of in vitro maturation (IVM), over 90% of oocytes were at Metaphase II. Before oocyte activation, oocytes were aligned using a 5 sec AC pulse of 0.25kV/cm. Activated oocytes were cultured in NCSU-23 + microfilament inhibitor for 6h, and then NCSU-23 for 6-7 days at 39oC, in 5%CO2 in air. In expt 1, oocyte age and activation field strength were examined. At d6, 44h IVM oocytes activated with 1 pulse of 1.5kV/cm produced the most blastocysts (41%, p<0.05). In expt 2, oocytes were activated as above but with multiple pulses (1,3 or 5), and 3x80 usec pulses of 1.0 kV/cm yielded more blastocysts (54%, p<0.01). In expt 3, the benefit of Ca+2 in the activation medium was tested, and 0.3M Mannitol + 0.1mM Mg+2 + 0.05mM Ca+2 gave the higher rate of blastocysts (44%, p<0.05). .In experiment 4, pig oocytes were activated by 3x80 usec pulses, 1.25kV/cm in Mannitol medium as above, or 0.3M Sorbitol + 0.1mM Mg+2 + 0.05mM Ca+2 or Zimmerman's fusion medium. At d7, the blastocyst rate and mean cell number per blastocyst were not significantly different (p>0.05) between the 3 media. Our data indicate that IVM pig oocytes activate best at 44h IVM with a preliminary 0.25kV/cm AC pulse for 5 sec, followed by 3x80usec DC pulses of 1.0kV/cm in either of three media.