Sperm quality of Persian sturgeon (Acipenser persicus) after Cryopreservation with Dimethyl Sulfoxide
Subject Areas : New Technologies in Aquaculture Development
Keywords: Acipenser persicus, cryopreservation, DMSO, Keywords: Sperm, Motility rate, Motility time,
Abstract :
The maximum ability of sperm for fertilization is 5-6 hours after collecting sperm from males in normal temperature. While by semen freezing and use of suitable extenders and cryoprotectants we can conserve it in liquid nitrogen for several years and we can use stored sperms in essential Conditions. Varied cryoprotectants are used in sturgeon semen cryopreservation but DMSO is the most important cryoprotectant. In this study, we have investigated the protective effect of DMSO as a cryoprotectant using different concentrations (8%, 10%, 12%, and 15%) and we have determined sperm motility rate and its motility time after thaw. The sperm of Persian sturgeon was collected from five males. They were diluted in appropriate extender containing Tris, Sacharose, egg yolk, and dimethyl sulfoxide in 1:1 ratio and the suspension were poured in to 0.5 ml straws and frozen in -196˚C liquid nitrogen vapour in a three storage program. Then straws were transferred to liquid nitrogen tank. The sperm samples were thawed in 40˚C water bath for 25s. The sperm motility rate and its motility time were observed using microscope. According to the results, the sperm motility rate after preservation in liquid nitrogen about 7 days were measured as 8.5±0.61, 12.54±2.57, 19±5.66, and 16.3±6.15% in concentrations 8%, 10%, 12%, and 15%; the sperm motility time after this time was 184.3±28.87, 267.3±36.54, 274±50.51, and 218±63.85s, respectively. Also the sperm motility rate after preservation in liquid nitrogen about 72 days were measured as 14.25±5.50, 10.50±1.61, 7.50±1.81, and 13.75±2.74%; the sperm motility time after this time was 195±39.50, 194.50±43.63, 154±37.34, and 221.70±47.31s, respectively. There was no statistical significant difference between selected concentration. However, 12 and 15% of DMSO had better motility rate and time. Results indicated that the increase in concentration of DMSO from 8% to 15% does not change the percentage of motile cells and motility time on sperm cryopreservation of Persian sturgeon.
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