Freeze fracture of sperm and vegetative cells in Zea mays pollen

Abstract

In freeze-fractured pollen of Zea mays, sperm cells were surrounded by concentric paired membranes. The sperm nucleus lacked nuclear pores. Sperm cytoplasm included mitochondria, endoplasmic reticulum, and several classes of single-membrane vesicles. No distinctive fracture patterns were observed on any sperm cell membranes.