In vitro Study of the Spermatozoa Motility in the Lizard Eutropis carinata

Abstract

Reptilian epididymis is considered as an important excurrent duct system required for the sperm maturation. Reptilian epididymis synthesizes and secretes proteins which vary in different regions of the epididymis. Hence, to investigate the effect of the secretions of different regions of the epididymis on spermatozoa motility, an in vitro study was undertaken to observe the changes in the patterns of motility of the testicular spermatozoa incubated with luminal contents of different regions of the epididymis in the lizard Eutropis carinata for the first time. The non motile testicular spermatozoa from the testis exhibited different patterns of motility, when incubated with the luminal contents of different regions of the epididymis. The spermatozoa from the testis, different regions of the epididymis exhibited 8 different patterns of motility (a-h). Testicular spermatozoa incubated with the anterior and middle epididymal luminal contents showed the motility patterns almost similar to that of the spermatozoa of the anterior and middle epididymis respectively. In contrast to the spermatozoa of the posterior epididymis, none of the testicular spermatozoa showed any movement when incubated with the posterior epididymal luminal contents. This study throws light on the importance of each region of epididymis in the physiological maturation of spermatozoa.

Epididymis of the Lizard <i>Eutropis carinata</i>: A Light Microscopic and Ultrastructural Seasonal Study

“…Unlike mammals, in the reptilian epididymis, there is no clear-cut demarcation dividing the epididymis into anatomical segments such as head, body, and tail as noted in primitive mammals 24 . However, the reptilian epididymis is not simply a spermatozoa storage organ but it is a highly dynamic organ secreting constituents of the seminal plasma 9,10,13,17,19,21,[25][26][27][28][29][30] . Major changes that occur during epididymal maturation in mammalian spermatozoa are the ability to move, recognize and bind to the zona pellucida, and to fuse with the plasma membrane of the oocyte 31 .…”

“…Major changes that occur during epididymal maturation in mammalian spermatozoa are the ability to move, recognize and bind to the zona pellucida, and to fuse with the plasma membrane of the oocyte 31 . Although epididymis has appeared for the first time in reptiles among vertebrates, there is not much understanding of spermatozoa maturation and the role of accessory gland secretions in this process in reptiles except for a few reports 21,25,27,29 . The first fine-structure analysis of reptilian epididymis was that of Mesure, et al, in the lizard Lacerta vivipara, in which four regions, caput, corpus, proximal cauda, and distal cauda, with only small differences from the head to the distal corpus were distinguished 19 .…”

Sperm Incubation in Bww Medium Induces Capacitation- Related Changes in the Lizard <em>Sceloporus torquatus</em>

“…Sperm capacitation remains uncertain in lizards, despite sharing characteristics such as internal fertilization and possession of the epididymis, where sperm acquire motility (Dosemane & Bhagya, 2015). Females also have the ability to store sperm in the oviducts, allowing an asynchrony between mating and ovulation (Martínez-Torres, 2009; Ortega- León et al, 2009).…”

Sperm Incubation in Biggers–Whitten–Whittingham Medium Induces Capacitation-Related Changes in the Lizard Sceloporus torquatus

“…Although fully recognized in mammals, sperm capacitation remains uncertain in lizards, despite sharing characteristics such as internal fertilization and the possession of the epididymis, where sperm acquire motility [6]. Females also have the ability to store sperm in the oviducts, allowing an asynchrony between mating and ovulation [7,8].…”