PROTEIN NEOSYNTHESIS BY PORCINE OOCYTES MATURED IN-VIVO AND IN-VITRO

The protein pattern of individual porcine oocytes matured as intact cu mulus oocyte complexes either in vivo or in vitro with or without FSH and LH for 43 h were investigated. The synthesis of a 53 kDa polypepti de ceased 21 h after hCG administration wheras a 44 kDa polypeptide we re consistently absent in the protein patterns of nearly all of the in vivo maturing oocytes. Furtheron, a polypeptide with a relative molec ular weight of 46000 persisted throughout maturation. A precipitous in crease in the synthesis of two other proteins with relative molecular weights of 38000 and 28000, respectively, was observed at 9 and 21 h a fter hCG injection. In in vitro matured oocytes with or without FSH an d LH the synthesis of the 53 kDa band decreased after a culture period of 9 h. Furtheron, the production of the 44 kDa polypeptide ceased on ly in oocytes incubated in FSH and U-l supplemented media after 21 h o f culture. On the other hand, the two proteins of Mr 38000 and 28000 a ppeared only in most of the protein profiles of oocytes cultured with FSH and LH for 43 h. The production of the 46 kDa polypeptide during a 21 h culture period was significantly affected by the presence of add itional granulosa cells in connection with the cumulus oocyte complex. Neither the appearance nor the disappearance of the 5 investigated ba nds was influenced by the presence or absence of the germinal vesicle after 21 h of culture. It is concluded that at least the addition of F SH and LH to the culture medium is necessary for cumulus oocytes compl exes to synthesize a protein pattern closely corresponding to that pro duced by in vivo matured oocytes.