Spermiogenesis and testicular cycle of the lizard Tropidurus torquatus (Squamata, Tropiduridae) in the Cerrado of central Brazil

Abstract

We studied the spermiogenesi s and testicular cycle of the lizard Tropidurus torquatus, using light and electron microscopy. Males bearing spermatozoa were present practically year-round and spermatogeni c activity showed a regenerative phase from late dry season to the end of the rainy season (July to March), with low frequency of initial stages of the spermatogeni c cycle, and a brief degenerative phase from April to June, lacking the total regression of seminiferous tubules. These characteristics resemble those from species with continuous reproductive cycles, contrasting with the strongly seasonal reproductive cycle of females. Spermiogenesis includes nuclear elongation, chromatin condensation, acrosomal and agellar development , and elimination of excessive cytoplasm. We describe some new aspects in the spermiogenesi s of T. torquatus, including the interaction between spermatid and Sertoli cell, acrosomal granule, subacrosomal granule, and the brous sheath formation. The testicular cycle of T. torquatus is very similar to that of other lizards that inhabit seasonal environments , and its spermiogenesi s and ultrastructure of mature sperm display a number of conservative features.

Reproductive Strategies of Brazilian Lizards of the Genus Tropidurus Rodrigues, 1987 (Squamata, Tropiduridae) in the Temporal and Spatial

“…However, important information about the reproductive activity of Neotropical lizards has arisen from studies of members from the family Tropiduridae (sensu Frost et al, 2001). In general, tropidurid lizards present their reproductive cycle in seasonal habitats; and studies on the ecology and reproductive cycles of some species of the genus Tropidurus has currently been studied, including T. etheridgei (Cruz, 1997), T. spinulosus (Cruz et al, 1997), T. semitaeniatus (Vitt & Goldberg;Ribeiro et al, 2010); T. montanus (Van Sluys et al); T. hispidus (Vitt & Goldberg;Vitt et al, 1996), T. oreadicus (Rocha & Bergallo, 1990), T. itambere (Van Sluys;Ferreira et al, 2009) and T. torquatus (Bergallo & Rocha, 1993Giaretta, 1996;Vieira et al;Wiederhecker et al) (see Table III). …”

“…Data were observed as regard the histology of the reproductive aspects for the family Tropiduridae ie, Tropidurus albermalensis (Stebbins et al, 1967) and Liolaemus austromendocinus and Prymaturus flagellifer (Furieri, 1974), T. hispidus (Prieto et al, 1976), T. delanonis (Werner, 1978), T. quadrivittatus and T. theresioides (Goldberg & Rodriguez, 1986), T. torquatus (Cruz-Landim & Cruz-Höfling, 1977;Cruz-Höfling & Cruz-Landim 1978;Vieira et al, 2001) and T. itambere (Van Sluys, 1993;Ferreira & Dolder, 2003a, 2003bFerreira et al, 2006;Ferreira & Dolder, 2007) and the family Iguanidae (ie. Saita et al 1988;, details of gametogenesis until fertilization of lizards under different climatic and seasonal conditions are scarcely known.…”

Spermiogenesis in Soft‐Shelled Turtle, Pelodiscus sinensis

“…The Golgi complex and the endoplasmic reticulum are well developed, the latter aggregating in patches. For purposes of comparison, the spermatid differentiation was graded into five consecutive stages according to the terminology of Gribbins et al (2003) and based on the classification of Vieira et al (2001).…”

“…In some Iguania, it enters the apex of the subacrosomal cone below the perforatorium where there is an electron dense plate: the perforatorial base plate (Scheltinga et al, 2000(Scheltinga et al, , 2001. However, this complex is not present in the lizard, Tropidurus itambere (Ferreira and Dolder, 2003) and other Tropidurus torquatus (Teixeira et al, 1999;Vieira et al, 2001). This is one of the few differences between this species and the Iguanidae.…”

Observaciones morfohistológicas del testículo y espermatozoides de Microlophus peruvianus (Lesson, 1826) (Sauria:Tropiduridae)

“…La presencia de diferentes líneas celulares, nos indica una alta actividad mitótica; este patrón, así como los volúmenes testiculares (129 mm 3 ) y los diámetros de los túbulos seminíferos (STD = 0,234 μm), son similares al patrón observado durante el estadio IV del ciclo testicular (auge de la espermiogénesis) de Tropidurus torquatus descrito por Vieira et al,(2001), (volumen testicular de 145 mm 3 , STD= 0,256 μm). Esto podría indicar que algunas especies de la familia Tropiduridae presentan sincronía en el desarrollo de la espermiogénesis y de sus ciclos reproductivos, al igual que lo que sucede con los Phrynosomatidae (Hernández-Gallego et al, 2002).…”