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

Abstract

Rheubert, J.L., Wilson, B.S., Wolf, K.W. and Gribbins, K.M. 2010. Ultrastructural study of spermiogenesis in the Jamaican Gray Anole, Anolis lineatopus (Reptilia: Polychrotidae). -Acta Zoologica (Stockholm) 91: 484-494.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.

Ultrastructure of the reproductive system of the black swamp snake (Seminatrix pygaea). VII. spermatozoon morphology and evolutionary trends of sperm characters in snakes

“…These multilaminar membranes have also been observed in pygopodids (Jamieson et al. 1996) and during spermiogenesis in Anolis lineatopus (Rheubert et al. in press) resulting from vesicles originating from the endoplasmic reticula.…”

“…These spermatozoa characters along with developmental features during spermiogenesis, which are also gaining much needed attention (Healy and Jamieson 1994; Gribbins et al. 2007, 2010; Rheubert et al. in press), have been considered a rich source of non‐traditional morphological characters that can be utilized in phylogenetic analyses (Jamieson 1991; Newton and Trauth 1992; Jamieson et al.…”

Ontogenic development of spermatids during spermiogenesis in the high altitude bunchgrass lizard (Sceloporus bicanthalis)

“…Squamate spermiogenesis follows the same general steps (acrosome formation, nuclear condensation and elongation, and flagellar development) as all vertebrates (including reptiles: Iguania and Scleroglossa) studied to date 10 , 11 , 16 , 17 with Sceloporus bicanthalis being no exception. However, the addition of new taxa into the accumulating data of sperm morphology reveals new characters and new insights into the steps of sperm development.…”

“…Only a handful of studies exist that give complete ultrastructural descriptions of spermiogenesis within the Squamata 9 . These studies have shown both conserved characteristics (i.e., nuclear elongation, acrosome development via Golgi vesicles) as well as unique characters (i.e., rough endoplasmic reticulum involvement in acrosome formation; 10 the absence of manchette microtubules) 11 . With each new study, important insights such as the number of Sertoli cells that are interacting with developing elongating spermatids, 12 become evident during germ cell development.…”

Reptilian spermatogenesis

“…20 and Scincella lateralis, Inset, ma) is found in all species of reptile studied to date during elongation except in Anolis lineatopus, which lacks a manchette all together. 58 The manchette is thought to aid in the elongation of the nucleus when present and is also represented in almost every mammal and bird. 2,26,56,64,68 The manchette has long been thought to be a major player in the elongation and constriction of the nuclear width during amniote spermiogenesis, 64,66 but the exact mechanism is not known.…”