Research Article

Histone deacetylase inhibition improves meiotic competence but not developmental competence in growing pig oocytes

J. Petr^a3, E. Chmelíková^a2, K. Kheilová^a1a2 c1 and F. Jílek^a2

^a1 Department of Veterinary Sciences, Czech University of Life Sciences Prague, 165 21, Kamýcká 129, Prague 6, Czech Republic.

^a2 Czech University of Life Sciences Prague, Faculty of Agrobiology, Food and Natural Resources, Department of Veterinary Sciences, Kamýcká 129, Prague 6, Czech Republic.

^a3 Research Institute of Animal Production, Přátelství 815, Prague 10, Czech Republic.

Summary

In fully grown pig oocytes, meiotic maturation in vitro is retarded by inhibition of histone deacetylases by trichostatin A (TSA). In growing oocytes with partial meiotic competence, culture with TSA has no significant effect on the meiotic maturation. Growing oocytes treated with TSA mature mainly to metaphase I. The ratio of oocytes that mature to metaphase II is very limited. After transient exposure to TSA, the maturation of growing oocytes with partial meiotic competence takes a different course. When these oocytes are first cultured in a TSA-free medium, then cultured for another 24 h with 100 nM TSA and finally again in a TSA-free medium for 24 h, the ratio of oocytes that mature to metaphase II significantly increases reaching 59%. When oocytes were cultured for the same length of time without transient exposure to TSA, only 19% matured to metaphase II. Those oocytes that matured to metaphase II after transient exposure to TSA were successfully activated using calcium ionophore. However, the subsequent cleavage was very limited. We can conclude that transient exposure of growing pig oocytes with partial meiotic competence to TSA increases oocyte meiotic competence, but it does not enhance developmental competence after parthenogenetic activation.

(Received October 07 2008)

(Accepted February 24 2009)

(Online publication May 22 2009)

Keywords:

• Activation;
• Meiotic competence;
• Oocyte;
• Pig;
• Trichostatin A

Correspondence:

^c1 All correspondence to: Kateřina Kheilová. Department of Veterinary Sciences, Czech University of Life Sciences Prague, 165 21, Kamýcká 129, Prague 6, Czech Republic. Tel: + 420 224382951. Fax: + 420 234381841. e-mail: kheilova@af.czu.cz