Single-layer centrifugation through colloid selects improved quality of epididymal cat sperm.
The objectives were to determine the: 1) extent of epithelial and red blood cell contamination in epididymal cat sperm samples recovered by the cutting method; 2) efficacy of simple washing, single-layer centrifugation (SLC), and swim-up for selecting epididymal cat sperm; and 3) effects of freezing and thawing on cat sperm selected by various techniques. Ten unit samples were studied; each contained sperm from the cauda epididymides of four cats (total, approximately 200 x 10(6) sperm) and was equally allocated into four treatments: 1) simple washing, 2) single-layer centrifugation through colloid prior to cryopreservation (SLC-PC), 3) single-layer centrifugation through colloid after cryopreservation (SLC-AC), and 4) swim-up. Centrifugation (300 x g for 20 min) was done for all methods. The SLC-PC had a better recovery rate than the SLC-AC and swim-up methods (mean+/-SD of 16.4+/-8.7, 10.7+/-8.9, and 2.3+/-1.7%, respectively; P<0.05). The SLC-PC, SLC-AC and swim-up samples contained less red blood cell contamination than simple washed samples (0.02+/-0.01, 0.02+/-0.04, 0.03+/-0.04, and 0.44+/-0.22 x 10(6) cells/mL, respectively; P<0.05). Although the proportion of sperm with head abnormalities did not differ among selection methods (P>0.05), SLC-PC yielded the highest percentage of sperm with normal midpieces and tails (P<0.05), due to the lowest proportion of coiled tails (P<0.05). Furthermore, the SLC-PC was as effective as swim-up in removing sperm with proximal droplets, and selecting motile sperm, as well as those with intact membranes and DNA (P>0.05). In conclusion, both SLC-PC and swim-up improved the quality of epididymal cat sperm, including better morphology, membrane and DNA integrity, and removal of cellular contamination. However, SLC had a better sperm recovery rate than swim-up.
Chatdarong
K
K
Department of Obstetrics, Gynaecology and Reproduction, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand. kaywalee.c@chula.ac.th
Thuwanut
P
P
Morrell
J M
JM
D000818:Animals; D002415:Cats; D002462:Cell Membrane / Q000502:physiology; D002469:Cell Separation / Q000379:methods / Q000662:veterinary; D002498:Centrifugation / Q000379:methods*; D003102:Colloids; D015925:Cryopreservation / Q000379:methods / Q000662:veterinary*; D004247:DNA / Q000032:analysis; D004822:Epididymis / Q000166:cytology*; D004847:Epithelial Cells; D004912:Erythrocytes; D006358:Hot Temperature; D008297:Male; D012662:Semen Preservation / Q000379:methods / Q000662:veterinary*; D013076:Sperm Count; D013081:Sperm Motility; D013094:Spermatozoa / Q000002:abnormalities / Q000502:physiology* / Q000648:ultrastructure
D003102:Colloids; D004247:DNA