Structure, cytoskeleton, and development of the acrosome of Platycleis albopunctata (Orthoptera : Tettigoniidae)

The acrosome of Platycleis albopunctata (Orthoptera: Tettigoniidae) is rela tively large and complex, consisting of an apical vesicle and two large win g-like extensions that give the spermatozoon the shape of an arrow. The win gs have actin microfilaments and microtubules and are covered with a notice able extracellular material. Actin filaments are present in the acrosome wh en it first appears in spermatid stages. The acrosome and the acrosomal att achment to the nucleus are more resistant than other structures to the redu cing agents DTT and SDS. At the end of spermiogenesis, groups of spermatozo a juxtapose their sperm heads and become joined to form a spermatodesm enci rcled by an amorphous material. Treatment with the ionophore A23187 rapidly disrupted acrosomes of the free gametes, but acrosomes from spermatozoa co ntained in the spermatodesm were not disassembled. Packaging of sperm in a spermatodesm appears to protect the acrosome.(C) 1999 Wiley-Liss, Inc.