Researches regarding the influence of the number of cumular cells layer over the oocyte maturation efficiency

During the experiments we have carried out with imature oocyte collected from the ovarian follicles, we found a variety of oocyte-cumulus complexes. We got the following experiment in order to understand the role of cumular cells on the achievement of the cytoplasma and oocyte nucleus maturation. We select the oocytecumulus complexes collected both from cows and sows according to the number of cumular cell layers and we watched their development to the blastocyst stade. Thus, we achieved three groups of COC (oocyte-cumulus complexes). One group was made of oocyte without cumular cells, the second group had a layer of cumular cells and the third group had many layers of cumular cells. we performed an incubation of all these types of COC in TCM-199 enriched with 20% of bovine fetal serum. Because only 1,2 oocyte of the ones who lack the cumular cells layer had maturation signs during cultivation in the thermostat versus 55 and 115, respectively, of the ones that had many cellular layers, presents a solid evidence that cumular cells are indispensable for the maturation and even to the fecundation process. The cumular cells perform a decisive role on the cytoplasma and oocyte nucleus maturation process.