Immunocytogenetic detection of normal and abnormal oocytes in human fetal ovarian tissue in culture.

Abstract

This study aimed to: (i) determine whether oocytes are present in cultures of human fetal ovary; (ii) identify whether meiotic anomalies are evident; and (iii) assess whether preparation or culture conditions influence oocyte survival and meiotic progression. Ovaries were collected from fetuses after termination at 13-16 weeks. Oocyte assessment utilized antibodies specific for synaptonemal complex proteins (associated with chromosomes only during meiosis), and antibodies to centromeric proteins. Fragments of tissue were cultured in minimal essential medium + 10% serum +/- follicle stimulating hormone (100 mIU/ml). The sera were fetal calf serum (FCS), FCS for embryonic stem cells (ES-FCS) and human female serum. The numbers and stages of oocytes were assessed after 7-40 days, and particular arrangements of chromosome synapsis identified. Results in fresh tissue included oocytes at leptotene, zygotene, pachytene and diplotene in three of five samples. Four specimens remained viable in vitro, and three had detectable oocytes after culture. The numbers of oocytes and the proportions of zygotene and pachytene cells increased with time in culture. The proportion of degenerate cells in culture was initially higher than in fresh samples, but declined subsequently. More oocytes were detected in ES-FCS and human serum than in FCS. We conclude that human oocytes survive in culture and that progression through prophase I continues.