title: Are accessory nuclei involved in the establishment of developmental gradients in hymenopteran oocytes? : Ultrastructural studies.
abstract: In the oocytes ofTenthredo olivacea, accessory nuclei (AN) are formed by budding from the nuclear envelope of the oocyte nucleus. Newly formed AN contain electron-dense material of nuclear origin and are surrounded by a double envelope devoid of pores. Such structures are subsequently transported to the peripheral ooplasm (periplasm), where they grow to reach a final diameter of 5 µm. In the envelopes of advanced AN nuclear pores arise. Through these pores "nuage" material is extruded into the surrounding periplasm. These findings are discussed with respect to a possible involvement of AN in the establishment of developmental gradients in hymenopteran oocytes.
authors.affiliation: Institute of Zoology, Jagiellonian University, Karasia 6, PL-30-060, Kraków, Poland.
authors.forename: Szczepan M
authors.initials: SM
authors.lastname: Biliński
keywords: Accessory nuclei; Developmental gradients; Oogenesis; Ultrastructure