significant change during storage (Table 2). Similarly, there were no
significant changes in the linear dimensions or area of the sperm heads
over the 9-day period (Table 2).

Table 2
The Effect of In Vitro Aging of Rabbit Spermatozoa
on DNA Content and Nuclear Size

 

 

DNA Storage Period (days)
relative units

 

1 2 3 4 5 9
Feulgen 2037 192" =208 74 KA I A0S/ 18
A cridine Orange 14.6 ¥55511h 1.5..8 149 10620 1985
U.V. (260mp) 5.10 - 4,99 - 4,98  5.11
Nuclear size (p2) 30.19 - 99 7F M |o=er +29. 8310112971

D ISCUSSION. The fertility levels at 32 hr and 15 days post insemination
duplicate the trend in dairy cattle inseminations when aged spermatozoa
are used (2). Fertilization rates are well maintained even on the fourth
day of storage but embryonic survival declines from the second day. The
small increases in fertilization rate and embryo survival on the second
day are not significant. During epididymal maturation it has been re-
ported that the Feulgen-DNA, but not the acridine orange fluorescence,
of bull sperm (5) and the Feulgen-DNA of rabbit sperm (6) decrease al-
though there is no change in U.V. absorption at 260mp . A fall in
Feulgen-DNA of bull sperm during in vitro storage hasbeen reported and
this has been associated with a signmcm reduction in head size (7)
although the latter was not confirmed (8). The techniques of estimating
D NA by microspectrophotometry appear to be relatively unreliable and
unless care is taken to avoid systematic errors including observer bias,
spurious results are likely.

IR OUNG, wWEE . (1231) S8, e xp .y Biol., 1 8:.18]1-162 |

2. SALISBURY, G.W. and FLERCHINGER, F.H. (1967). J. Dairy Sci.,
50: 1675-1678.

3. LEUCHTENBERGER, C. (1958). in General Cytochemical Methods.
(J.F. Danielli, editor), New York and London, Academic Press,
Inc, 1: 219-278.

4, von BERTALANFFY, L., MASIN, F., and MASIN, M. (1956).
Science, 124: 1024,

5. GLEDHILL, B.L., CLEDHILL, M.P,, RIGLER, R,, Jr,, and
RINGERTZ, N.R. (1966). Exper. Cell Res., 41: 652-663.

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