Ultrastructural study of spermiogenesis in the Jamaican Gray Anole, Anolis lineatopus (Reptilia: Polychrotidae)

As the number of spermatozoal characters being described in reptiles increases, it is important to detail the ontogeny of the features leading to the mature morphology of the spermatozoa which may give rise to more comprehensive data matrices for future phylogenetic analyses within the Reptilia. Therefore, spermiogenically active testes from Anolis lineatopus were investigated ultrastructurally to describe the intracellular changes that occur throughout spermiogenesis. The primary events of spermiogenesis (acrosome formation, nuclear condensation, and elongation) seen in A. lineatopus are similar to those previously described for other amniotes. Characters including a round perforatorium tip, stopper-like perforatorial base plate, open pits of nucleoplasm during condensation, and protein layers within the acrosome complex corroborate trends from previous studies in squamates. However, uniquely defined in A. lineatopus are the excessive amounts of endoplasmic reticulum and Golgi complexes that contribute to cellular secretions during mid elongation of the spermatids and the lack of a manchette. During acrosome formation, the acrosome granule is found in a basal rather than an apical position, which has been observed in previous studies. These similarities and differences observed during spermiogenesis may be helpful in elucidating the development of mature spermatozoal characters as well as aid in future phylogenetic analyses.