Abundance of poly (a) binding protein in bovine oocytes during in vitro maturation

Abstract

To improve the conditions for in vitro production of embryos in animal husbandry it can be helpful to obtain deeper insights into regulatory mechanisms which are directing maturation of oocytes on a molecular level. Recent observations have shown that protein synthesis in mature oocytes (metaphase II stage) is impaired. Although oocytes possess a stockpile of mRNA at this stage of development, the translation of these mRNAs is repressed. It has been shown that essential components of cap dependent regulation of translation (eIF4E, 4E-BP1) potentially could attend in this process. More recent investigation suggest that these factors probably not alone modulate translation rates during in vitro maturation of bovine oocytes. Therefore in the present study the abundance and potential modifications of another regulator of translation, namely the poly (A)-binding protein was analysed. This protein was shown to bind to mRNAs poly-(A)tails and link them to the cap-binding complex eIF4F. By this mechanism, cap dependent translation should by synergetically stimulated. In the present study, we have analysed the abundance of poly (A) binding protein in the course of meiotic maturation and we have elucidated potential expression of isoforms or post translational modifications of this protein by 2D-Gelelectrophoresis.

Meiotic maturation and in vitro maturation of bovine oocytes

“…In this way the cooperation between 3´ and 5´ mRNA binding factors were proofed to be involved in the modulation of translation rates during meiotic maturation of bovine oocytes. (Smiljaković et al, 2003, Smiljaković et al, 2004, Tomek & Smiljaković, 2005, Miščević et al, 2005, Smiljaković, 2006.…”