Changes in the nuclear envelope associated with spermatid differentiation in the shrimp, Crangon septemspinosa

The nuclear envelope during the sequential steps of spermiogenesis in the shrimp, Crangon septemspinosa, was followed by electron microscopy of thin-section and freeze-fracture preparations. Localized modifications of the nuclear envelope were observed which are consistent features, identifiable and unique to particular regions of this intact membrane system at specific stages during spermatid differentiation and in the mature sperm. The …