RECURRENT FAILURE IN POLAR BODY FORMATION AND PREMATURE CHROMOSOME CONDENSATION IN OOCYTES FROM A HUMAN PATIENT - INDICATORS OF ASYNCHRONY IN NUCLEAR AND CYTOPLASMIC MATURATION

All oocytes from a patient who had undergone four unsuccessful in-vitr o fertilization attempts showed neither a polar body nor pronuclei whe n examined for fertilization. In 19 inseminated oocytes that were spre ad for karyotypic analysis, one haploid set of metaphase II chromosome s and a remarkable condensed structure were found. Hormonal and morpho logical criteria implied that the oocytes had been mature at the time of retrieval. Since non-inseminated oocytes contained only one set of metaphase II chromosomes, the condensed structure appeared to represen t the sperm chromatin in the state of premature chromosome condensatio n due tea block in oocyte maturation, Since the first and second polar body, as well as their chromatin, were undetectable in all the patien t's oocytes, a rapid maturation to metaphase II before retrieval and p rolonged arrest in this state before fertilization, accompanied by deg eneration of the first polar body, appear to be responsible for the co ndition, In accordance with this notion, degenerate spindles (typical of post-ovulatory aged oocytes) and separating chromosomes (probably r epresenting presegregating chromatids) were observed by antitubulin im munofluorescence.