ABSTRACT
Determmation of the chomosomal constitution of human spermatozoa has been camed out though the human-hamster interspecific in vitro fertilization(IVF) system. In recent years, the introduction of fluorescence in-situ hybridization(FISH) technique has provided an alternative approach to evaluate the cbmmosomal constitution of human spermatozoa. The nuclei of mature spermatozoa are highly condensed with interpmtamine disulphide bridges, therefore the success of FISH on interphase human spermatozoa relies on partial decondensation of the sperm chromatin. In early studies, dithioothreitol(DTT) has been known as an efficient decondensation agent. Since then, several different decondensation methods using D1T have been establisdhed, and in terms of decondensation, we were tried to fix the optimal decondensation protocol using DlT. In our study, the optimal concentration and treatment time were 1-mM and 30 min, respectively. We examined chromosome complements of human sperm to investigate the effect of paternal age on the hequency of nondisjunction in human sperm. We investgated sperm karyotypes ftom two diffaent age groups)28+/-0.5, 46+/-6), A minimum of 1000 spermatozoa for one patient were analyzed. The mean frequencies of YY, XX, XY, 21-disamy spermatozoa ware 0.04%, 0.45%, 0.40%, 0.45% respectively in young age group and 1.06%, 0.62%, 1.06%, 0.76% in old ages. The mean frequency of disomy spermatozoa was higher in old age poup compare with those of young age group.