Effect of antifreeze proteins on the motility of ram spermatozoa.
The effect of the antifreeze peptide type I (AFP) from Winter flounder, Pseudopleuronectes americanus, and the antifreeze glycoprotein (AFGP) from Antarctic cod, Dissostichus mawsoni, was assessed on the motility of ram spermatozoa (Dorset and Dorset x Romney) after chilling (5 degrees C) and after freeze-thawing. During chilling, spermatozoal motility decreased significantly at an AFP or AFGP concentration of 0.1 microgram/ml and at concentrations above 10 micrograms/ml (P < 0.05). Thus, at 5 degrees C these antifreeze proteins can have a mildly cytotoxic effect at certain concentrations. Addition of AFP or AFGP to the freezing medium at concentrations of 0.1 to 10 micrograms/ml significantly reduced the loss in spermatozoal motility that occurs due to the freeze-thaw process (P < 0.001). The effect was not concentration dependent nor did it depend on which antifreeze protein was added. However, due to the cytotoxicity during the chilling stage, only AFP at a concentration of 10 micrograms/ml increased the percentage of motile spermatozoa significantly following freezing and thawing over that of the control (P < 0.05). Mechanisms to explain the effect of these proteins on spermatozoal motility after chilling and after freeze-thawing are proposed.
Payne
S R
SR
Meat Industry Research Institute of New Zealand, Hamilton.
Oliver
J E
JE
Upreti
G C
GC
D000818:Animals; D021301:Antifreeze Proteins; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology; D005069:Evaluation Studies as Topic; D005399:Fishes; D005432:Flounder; D005615:Freezing; D006023:Glycoproteins / Q000302:isolation & purification / Q000494:pharmacology*; D066298:In Vitro Techniques; D008297:Male; D012756:Sheep; D013081:Sperm Motility / Q000187:drug effects*
D021301:Antifreeze Proteins; D003451:Cryoprotective Agents; D006023:Glycoproteins