Cecilie Leuchtenberger

The desoxyribosenucleic acid (DNA) content in spermatozoa of fertile and infertile human males

SummaryMicrospectrophotometric studies were made on the amounts of DNA in individual spermatozoa of 21 human males with proven fertility and on 18 human males who are partners in sterile couples. The results were as follows:1.The amount of DNA per spermatozoon of the 21 fertile males is very constant and uniform within each individual and among the 21 different individuals. The mean amount of DNA in arbitrary units is 1.22±0.005 per sperm and is approximately one-half that of human somatic cells which is 2.66±0.05.2.In contrast to the uniformity of DNA in the sperms of fertile males, the sperms from the 18 males under examination for “suspected sterility” showed greatly varying amounts of DNA.3.6 of this suspected group had DNA values close to, but not exceeding that of the fertile males. But for 4 of these 6 males this normal DNA amount conformed to the clinical diagnosis that not the males, but their female partners were responsible for the infertility. The remaining 2 males had sperms with impaired motility, a manifestation which may involve a different factor than that of deviations in the amount of DNA.4.5 males represented a category of borderline cases in which the mean DNA was slightly lower than that of the normal group, but many individual measurements overlapped those of normal sperms. So far as the clinical diagnosis was concerned, 4 of these 5 males were on the borderline for male fertility while 1 male had been diagnosed as infertile because he had sperms with impaired motility.5.7 of the suspected group carried sperms with DNA in decidedly lower amounts than those of normal, fertile sperms. In 5 of these 7 males the clinical diagnosis ascribed the infertility to the males. In the remaining 2 cases where the DNA was also found to be low in the spermatozoa, no cause could be given clinically for the sterility either in the male or in the female partner.6.These data suggest a correlation between a deficiency of DNA in the sperms and one type of male sterility, but this cannot be considered as established until further data (such as more information on the female partner) become available.

The possible role of the DNA content of spermatozoa for the activation process of the egg of the clam, Spisula solidissima.

Summary1.Sperm nuclei within activated eggs of the clam, Spisula solidissima were found to contain a normal haploid amount of DNA while sperm nuclei in inactivated eggs of the same clam contain significantly lower amounts of DNA.2.The DNA content of sperm nuclei within activated eggs increases to approximately the diploid amount during pronuclei formation whereas the DNA content of sperm nuclei in inactivated eggs does not show any increase.3.The amount of DNA in spermatozoa in the testis of Spisula varies from one clam to another. Some clams have predominantly the normal haploid amount of DNA while others show significantly lower amounts of DNA in the spermatozoa in the testis.4.The possible significance of the DNA content of spermatozoa for the activation process of the Spisula egg is discussed.

EFFECT OF X-IRRADIATION ON THE DNA CONTENT OF INDIVIDUAL NUCLEI OF RABBIT BONE MARROW

Abstract 1. 1. Feulgen microspectrophotometric studies of DNA were conducted on individual nuclei of non-irradiated and irradiated femoral marrows of rabbits exposed to 800 r hemi-body X-irradiation. 2. 2. The major portion of the measured marrow nuclei from the non-irradiated marrow cells are in the range between 6 and 12 × 10 −9 mg of DNA per nucleus. These cells have been designated as synthesizing cells. 3. 3. The main consequence of X-irradiation to the exposed femurs has been to reduce the number of synthesizing cells. Studies conducted at 24 and 48 hours post-irradiation reveal a consistent decrease in the number of synthesizing cells. At intervals of X-irradiation less than 24 hours, the results were variable although indicative of a decrease in synthesizing cells. 4. 4. Studies on comparable nuclear sizes of X-rayed and non-X-rayed femoral marrow reveal a reduction of synthesizing cells in the larger nuclei (2.7–3.5 + arbitrary units). In the case of nuclear size ranges below 2.7 and erythroblasts (nuclear size range 2.0–2.7 arbitrary units) there are no significant effects of X-irradiation.