Fluorescent staining as a method of assessing membrane damage and post-thaw survival of ram spermatozoa.
We studied the relationship between motility and membrane damage, as assessed by fluorescent staining, in fresh and in frozen-thawed ram spermatozoa. Semen from Merino rams was incubated with 6-carboxyfluorescein diacetate and propidium iodide. In both fresh and frozen-thawed samples, the percentage of intact spermatozoa was lower than the motility rate, thus indicating the presence of damaged but motile spermatozoa. Freezing and thawing resulted in a marked loss of membrane integrity, whereas motility decreased to a lesser extent. There was a positive relationship (r=0.64; P<0.001) between membrane integrity immediately after thawing and motility after 8 h of incubation at 37 degrees C. These results demonstrate the usefulness of the fluorescent staining method for the prediction of ram sperm quality and post-thaw survival.
Valcárcel
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A
Centro de Investigaciones Reproductivas Pérez Companc Florida 234, 1334 Buenos Aires, Argentina.
de Las Heras
M A
MA
Pérez
L
L
Moses
D F
DF
Baldassarre
H
H