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

Sperm capacitation involves biochemical and physiological changes that enable sperm to fertilize the oocyte. It can be induced in vitro under controlled conditions that simulate the environment of the oviduct. While extensively studied in mammals, its approach in lizards remains absent. Understanding the mechanisms that facilitate reproduction is essential for advancing the implementation of assisted reproductive technologies in this group. Fifteen males of Sceloporus torquatus were collected during the early stage of the reproductive season. The sperm were isolated from the seminal plasma and then diluted up to a volume of 150 μl using BWW medium to incubate with 5% CO2 at 30 °C for a maximum duration of 3 hours. A fraction was retrieved hourly for ongoing sperm assessment. We found that total motility is maintained up to 2 hours post-incubation, after which it decreased. However, sperm viability remained constant. From that moment on, we observed a transition to a deeper and less symmetrical flagellar bending in many spermatozoa. The chlortetracycline assay indicated a reduction in the percentage of sperm showing the F pattern and an increase in those exhibiting the capacitated (B) and reactive (RA) patterns, accompanied by an elevation in the percentage of damaged acrosomes as revealed by the lectin binding assay. In mammals, these changes are often associated with sperm capacitation. These observations support the notion that this process may also occur in saurian.