110. DIMETHYL FORMAMIDE IMPROVES THE DNA INTEGRITY AND MOTILITY OF SEX-SORTED CRYOPRESERVED STALLION SPERMATOZOA
Z. Gibb A , L. H. A. Morris B , W. M. C. Maxwell A and C. G. Grupen AA Faculty of Veterinary Science, The University of Sydney, Camperdown, NSW, Australia.
B EquiBreed NZ Ltd., Cambridge, New Zealand.
Reproduction, Fertility and Development 22(9) 28-28 https://doi.org/10.1071/SRB10Abs110
Published: 6 September 2010
Abstract
The fertility of flow-cytometrically sex-sorted stallion spermatozoa is compromised by the additional stress of cryopreservation, a step which is essential for the wider application of this technology. The aim of this study was to compare the cryoprotective effects of dimethyl formamide (DMF) and glycerol at different concentrations. Sex-sorted and control spermatozoa were cryopreserved in the presence of 2, 3 or 4% DMF or glycerol. Post-thaw total motility (TM) was assessed using computer assisted sperm assessment and viability was assessed using Syto-16/propidium iodide staining and flow cytometry at 0, 45 and 90 min post-thaw. The DNA integrity (%DFI) was determined using the sperm chromatin structure assay immediately post-thaw. Compared to controls, se x-sorting caused a significant decrease in TM (34.6 vs. 9.4%) and viability (30.0 vs. 12.5), and a significant increase in %DFI (11.3 vs. 63.2%). The TM of control and sex-sorted spermatozoa did not differ at 0 min (29.2 vs. 22.0%), but were significantly different at 45 and 90 min (37.4 vs. 5.6% and 37.2 vs. 0.5% respectively). The viability of sex-sorted spermatozoa decreased significantly at each time point (20.9, 9.6 and 6.9% at 0, 45 and 90 min) though the viability of control spermatozoa did not decrease over time. DMF resulted in lower %DFI values than glycerol for sex-sorted, but not control spermatozoa (59.6 vs. 66.0). However, DMF reduced the viability of sex-sorted spermatozoa compared with glycerol (11.0 vs. 13.9%). DMF resulted in higher TM than glycerol for control spermatozoa only (37.9 vs. 31.3%). Increasing the cryoprotectant concentration caused a significant decrease to the viability of control spermatozoa (33.4, 30.8 and 25.9% for 2, 3 and 4% respectively), but had no effect on sex-sorted spermatozoa. The results of this study indicate that the cryoprotective effect of DMF on sex-sorted stallion spermatozoa was superior to that of glycerol.
