DISCUSSION. It has been postulated that the loss of Feulgen staining
DNA from aged spermatozoa could account for the known increase in
embryonic-losses after insemination of aged spermatozoa8,3,2. It
should, however, be emphasized that the basic cause of embryological
involvements associated with the aging of spermatozoa in mammals re-
mains unknown. Gledhill4,5,6 has shown that changes in Feulgen
staining are related to the binding of DNA to nuclear proteins rather
than to quantitative changes in DNA per se. In the present study
where DNA was quantitatively determined no loss was detected from the
live cells. If one assumes that only a live spermatozoon can ferti-
lize an ovum; and furthermore, that no spermatozoa of low DNA existed
in the live fraction, then there is little reason to expect a rela-
tionship between quantitative loss of DNA and embryo survival. How-
ever, the possibility exists that some spermatozoa retained by the
filter-bed in the present study after having lost some DNA were alive
and capable of activating ova. Subsequent to activation by such
spermatozoa, an embryo may not be carried through full term, because
of inadequate genetic information.

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