You are here:
ANEUPLOIDY AND CHROMOSOME BREAKAGE IN SWIM-UP VERSUS UNPROCESSED SEMEN FROM TWENTY HEALTHY MEN
Citation:
Ong, T. D., L. Xun, S D. PERREAULT, AND W. A. Robbins. ANEUPLOIDY AND CHROMOSOME BREAKAGE IN SWIM-UP VERSUS UNPROCESSED SEMEN FROM TWENTY HEALTHY MEN. JOURNAL OF ANDROLOGY. American Society of Andrology, Schaumburg, IL, 23(2):270-277, (2002).
Description:
Toxicologic and epidemiologic studies have investigated a number of factors believed to induce cytogenetic damage in human sperm cells in order to estimate heritable risk to future generations. Most of these studies, however, have not enriched research semen specimens for fertile or motile cells. In the clinical setting Intracytoplasmic Sperm Injection (ICSI) bypasses natural selection of sperm in fertilization by placing cells directly into eggs. Although practitioners attempt to select a motile sperm for ICSI, the selected sperm does not need to demonstrate motility, maturity, or even viability. In any case, there is concern the procedure may increase cytogenetic/genetic risk to future generations. For both toxicology and epidemiology research, and for ICSI, it would be beneficial to know if cytogenetic damage differs in motile versus unselected sperm as this would affect estimates of heritable risk. To address this question, we divided semen samples from 20 healthy donors and compared aneuploidy and chromosome breakage in sperm cells gathered directly from the ejaculate (unprocessed semen) to cells enriched for motility using swim-up. Sperm fluorescence in situ hybridization (FISH) was used to detect aneuploidy for chromosomes 13, 18, 21, X and Y. Tandem labeling probes were used to detect breakage in the 1cen-1q12 region of chromosome 1. For all chromosomes evaluated, aneuploidy frequencies were lower in specimens enriched for motility compared to unprocessed semen. The differences were statistically significant for disomy 18-18 (p=0.004) and XY18 (p=0.001). Sperm carrying duplication errors and diploid sperm were also lower in swim-up semen (p<0.008). Chromosome 1 breakage did not differ between swim-up and unprocessed specimens. Findings suggest that unprocessed semen may overestimate heritable risk in sperm biomarker studies and the categories demonstrating 1.4 to 1.8 fold differences (disomy 18, XY18) may be biologically relevant to ICSI.