Morpho-functional considerations on the annulate lamellae of the human oocyte]

Ovarian biopsy specimens from four girls in complete remission state of acute lymphoblastic leukemia, previously treated with antiblastic chemotherapy for about three years, were examined by means of electron microscopy. The normal morphology of residual follicles and, in particular, the observation that annulate lamellae were always present in oocytes of primordial and primary follicles, gave the chance to consider a possible functional role and to suggest a prognosis for future fertility. The similarities in structure to the nuclear envelope and the relation between annulate lamellae and other cellular organelles (especially endoplasmic reticulum and ribosomes) suggest that lamellae may be involved in the release, assembly or activation of stored development information. The annulate lamellae could prove to be an important organelle that participates in the regulation of gene expression. Therefore, the presence of annulate lamellae in oocytes of primordial and primary follicles may present the possibility of a normal development for these cells in which long-lived gene products are synthesized and transported to the cytoplasm for storage and use later in development. The above hypothesis, while leads to consider these patients at risk for low fertility and early menopause, does not consider them as definitely infertile.