Optimization of the cryopreservation of African clawed frog (Xenopus laevis>) sperm
This study is summarised as evidence for the following.
Freeze sperm or eggs for future useAction Link
Freeze sperm or eggs for future use
A replicated study in 2008 of captive African clawed frog Xenopus laevis in Austria (Mansour, Lahnsteiner & Patzner 2009) found that the most effective cryopreservation protocol was sperm in motility-inhibiting saline (MIS) with 5% dimethyl sulfoxide and sucrose, frozen 10 cm above liquid nitrogen and thawed at room temperature for 40 seconds. Sperm motility and viability was significantly higher following incubation (>10 mins) at 4°C in 10% dimethyl sulfoxide (motility: 40–50%; viability: 65–75%) than in 5% glycerol (10–30%; 15–55%) or 10% methanol (0–15%; 0–35%). Sperm in 10% dimethyl sulfoxide frozen 10 cm above liquid nitrogen (motility: 20%; viability: 50%) and thawed at room temperature for 40 seconds (20%; 48%) had significantly higher motility and viability than sperm frozen 5 cm (1%; 8%) or 8 cm (8%; 16%) above liquid nitrogen and thawed at 5, 25, or 30°C for 10, 15 or 60 seconds respectively (1–8%; 6–20%). Sperm frozen in MIS with 5% dimethyl sulfoxide resulted in higher hatching rate (29%) than sperm frozen in sucrose or glucose (300 mmol/L) containing 5% or 10% dimethyl sulfoxide (6–19%) or in MIS containing 10% dimethyl sulfoxide (9%). Viability did not differ (24–38%). Addition of 73 mmol/L sucrose to MIS with 5% dimethyl sulfoxide increased sperm motility (18 to 46%) and hatching rate (29 to 48%). Testes from three males were macerated and tested/treatment. Fertilization was tested using 25–30 eggs at 18°C.