Aneuploidy and diploidy rates in sperm of five men after three-colour hybridization: indication of X chromosome-associated autosome 2 aneuploidy.
The frequencies of aneuploidy and diploidy for chromosomes 2, X and Y in sperm nuclei of five nonsmoking normal donors were assessed by three-colour fluorescence in situ hybridization. We detected neither significant interindividual variability nor age effect (age range of the study group: 26-38 yr) on the mean frequencies of aneuploid and diploid sperm. Nullisomic sperm were observed more frequently than disomic sperm. In addition, sex chromosomal meiotic nondisjunction occurred at a higher rate than autosomal nondisjunction, and disomic sperm for the sex chromosomes were formed mainly by errors in the second meiotic division. Our data indicate that diploidy occurs at a very low frequency in comparison with aneuploidy. Furthermore, the overall proportion of X-bearing sperm nuclei aneuploid for chromosome 2 is significantly higher than that of Y-bearing sperm (0.14% vs. 0.05%, respectively; p < 0.001). This finding adds further evidence that autosomal aneuploidy can be preferentially associated with the presence of one of the two gonosomes.
Scarpato
R
R
Dipartimento di Scienze dell'Uomo e dell'Ambiente, Università di Pisa, Italy.
Naccarati
A
A
Mariani
M
M
Migliore
L
L
D000328:Adult; D000782:Aneuploidy; D002889:Chromosomes, Human, Pair 2 / Q000235:genetics*; D004252:DNA Mutational Analysis; D004171:Diploidy; D006801:Humans; D017404:In Situ Hybridization, Fluorescence / Q000379:methods*; D008297:Male; D008540:Meiosis / Q000235:genetics; D009630:Nondisjunction, Genetic; D013076:Sperm Count; D013094:Spermatozoa / Q000002:abnormalities*; D014960:X Chromosome / Q000235:genetics*; D014998:Y Chromosome / Q000235:genetics