Automated evaluation of frequencies of aneuploid sperm by laser-scanning cytometry (LSC)

Background: Laser-scanning cytometry (LSC) allows fast automated scoring of fluorescence signals directly on microscopic slides. Frequencies of sponta neous aneuploidies in murine and human sperm were evaluated by using this n ew LSC technique. Rapid detection may be of great interest in reproductive toxicology, as certain chemicals act as aneugens during meiosis, increasing the production of aneuploid germ cells. Materials and Methods: Selected chromosomes were detected by using fluoresc ence in situ hybridization (FISH) and fluorochrome-labeled DNA-probes. Sper m chromatin was counterstained with propidium iodide. By scanning across th e slide, fluorescence signals within sperm nuclei were detected and counted . Results: In murine sperm, the frequencies of disomies for chromosomes 8 and X were 0.019% and 0.021%, respectively. The automated assessment in human sperm resulted in disomy frequencies of 0.061% and 0.090% for chromosomes 1 3 and X, respectively. These results were comparable to data obtained from the same samples by manual microscopic scoring and to literature data. Conclusions: Frequencies of genotypically abnormal sperm were not significa ntly different between automated and manual scoring. In conclusion, sperm a neuploidy was reliably determined and disomic sperm were successfully reloc ated by LSC. By virtue of rapid and reliable analyses, LSC has the powerful potential to replace manual microscopic FISH analysis in molecular cytogen etics. Cytometry 44: 156-160, 2001. (C) 2001 Wiley-Liss,Inc.