S. Ohsako et al., COMPARISON OF THE NUCLEAR-DNA STABILITY AGAINST FREEZING-THAWING AND HIGH-TEMPERATURE TREATMENTS BETWEEN SPERMATOZOA AND SOMATIC-CELLS, Journal of veterinary medical science, 59(11), 1997, pp. 1085-1088
Thermostability of sperm genome against freezing-thawing and high temp
erature treatments was assessed by comparing the degradation patterns
of genomic DNAs from epididymal sperms and somatic tissues. Golden ham
ster liver, kidney, epididymal sperm, and testis were frozen and thawe
d repeatedly, or incubated in a hot water bath. Genomic DNAs were isol
ated and then separated by agarose gel electrophoresis. It was reveale
d that the size of sperm genomic DNA was hardly changed after freezing
-thawing treatment, however, the DNA sizes of the other three tissues
were gradually reduced with an increasing number of freezing-thawing c
ycles. In contrast, high temperature treatment appears to damage not o
nly the genomic DNAs of somatic cells but also those of spermatozoa.