Pretreatment of Addra gazelle (Nanger dama ruficollis) spermatozoa with cholesterol-loaded cyclodextrins improves cryosurvival

Abstract

Preserving genetic diversity of the critically endangered Addra gazelle (Nanger dama ruficollis) could be enhanced through the use of frozen-thawed sperm and artificial insemination. Our aim was to characterize Addra ejaculate traits and to assess the effects of cholesterol-loaded cyclodextrin (CLC) on sperm cryosurvival. Fresh ejaculates were treated with CLC (0, 0.5, 1.5, 3.0, and 6.0 mg/ml) prior to cryopreservation. All males produced spermic ejaculates with >75% sperm motility. The mean ± SEM seminal volume, sperm concentration, percent motility, forward progression, and percent morphologically normal spermatozoa were 3.2 ± 0.3 ml, 1.2 ± 0.3 × 10, 75.82 ± 2.7%, 3.2 ± 0.3 (0-5 scale; 5 = most progressive), and 57.12 ± 3.8%, respectively. More than 92% contained an intact acrosome. There was no effect of time or in vitro incubation on progression or acrosomal integrity on thawed samples (P > 0.05). Spermatozoa pre-treated with 0.5 mg/ml CLC retained higher (P < 0.05) motility post-thaw than aliquots treated with 0, 3.0, or 6.0 mg/ml of CLC. Spermatozoa pre-treated with 0.5, 1.5, or 3.0 mg/ml CLC exhibited greater viability than counterparts (P < 0.05). Sperm kinetics including beat cross frequency (BCF), average path velocity (VAP), curvilinear velocity (VCL), and straight line velocity (VSL) did not differ among samples (P > 0.05). Linearity (LIN) and straightness (STR) were different among samples after thawing. Results demonstrate treatment with CLC (0.5 mg/ml) protects Addra spermatozoa from cryo-damage. Reported advances will facilitate establishment of a frozen repository and support the genetic management of this critically endangered north African desert antelope.

Addition of low concentration of cholesterol-loaded cyclodextrin (CLC) has a positive effect on cryopreserved canine spermatozoa evaluated by andrological and biophysical methods

“…The significantly higher number of cells with progressive movement and rapid cells obtained with spermatozoa cryopreserved in the extender with 0.5 mg/120 × 10 6 sperm of CLC confirmed the more effective preservation of sperm cell function exerted by cholesterol insertion to cell membrane. The best concentration of cholesterol loaded cyclodextrins was 0.5 mg/120 × 10 6 sperm, and this result confirms similar findings in gazelle [ 35 ] and bull [ 36 ]. It has been reported that other low concentrations (0.75 mg/120 × 10 6 sperm, 1 mg/120 × 10 6 sperm and 1.5 mg/120 × 10 6 sperm) of CLC had a positive effect on motility parameters in ram [ 22 ] and bull [ 21 ].…”

Does Better Post-Thaw Motility of Dog Sperm Frozen with CLC Mean Better Zona Pellucida Binding Ability?

“…Extender with addition of 1 mg of CLC had no impact on the sperm features evaluated by CASA. The best concentration of cholesterol-loaded cyclodextrins was 0.5 mg, and this result confirms similar findings in stallions [19], gazelles [40] and bulls [41]. It has been reported that other concentrations such as 0.75 mg, 1 mg and 1.5 mg of CLC also had a positive effect on motility parameters in rams [14], stallions [42] and bulls [43].…”

Bilateral Intratesticular Spermatoceles in a Critically Endangered Dama Gazelle (Nanger dama mhorr)

“…Anesthesia was supplemented with ketamine hydrochloride (1.0 mg/kg; IV) and propofol (0.5 mg/kg; IV) to maintain an optimal anesthetic plane. Animal was subjected to a physical examination, testicular measurements, an ultrasound assessment of testes (5 MHz linear probe), and semen collection by electroejaculation [8]. Testicular ultrasound revealed well-demarcated, round, anechoic structures in the testicular parenchyma of both testes (Figures 1 and 2).…”