Accumulation of gene products in the oocytes of the dragonfly Cordulia aenea. II. Induction of annulate lamellae within dense masses during diapause.

During the 3 years of nymphal development of the dragonfly Cordulia aenea, gene products slowly accumulate in the cytoplasm of the previtellogenic oocytes. Nuclear extrusions separate into nematosome and dense-mass components. The dense masses, RNP-containing globules of thightly packed fibrillar material, disperse throughout the oocyte cytoplasm. The last instar nymph experiences an obligatory diapause, after which oocyte development passes from mid to late previtellogenesis, and eventually to vitellogenesis proper in the adult. During diapause, annulate lamellae are induced within the dense masses. This process is continued during late previtellogenesis. The formation of annulate lamellae may be related to activation of some genetic message stored in the dense masses. The possibility of tubulin synthesis is discussed.