The proposed research is aimed to contribute the data on the role of microtubules in human oogenesis and fertilization, using Rhesus monkey as a model animal. Four basic questions will be addressed: 1. What is the organization of microtubules and meiotic apparatus during oocyte maturation and fertilization? 2 Is there evidence for a paternal centrosome contribution during normal fertilization and polyspermy? 3. Will parthenogenetically activated Rhesus oocytes organize a bipolar mitotic apparatus at the time of first division? 4. What is the role of microtubules during Rhesus fertilization? The methods used in the study include conventional immunofluorescence, laser scanning confocal microscopy, transmission electron microscopy, time lapse video microscopy, ultrastructural immunocytochemistry and the methods of in vitro maturation and fertilization. The immunocytochemical methods will take profit from the availability of new antibodies against alpha, beta - tubulins, kinetochores, centrosomes and microtubule organizing centers. The expected results should accomplish the knowledge about basic processes occurring during the oogenesis and fertilization, which belong to the most important problems of human reproduction.