Rapid chromosome detection by PRINS in human sperm

Area of Science:

• Human genetics
• Reproductive biology
• Cytogenetics

Background:

• Aneuploidy, an abnormal chromosome number, is a significant cause of infertility and developmental disorders.
• Accurate estimation of disomy rates in human sperm is crucial for understanding male infertility and genetic risks.
• Existing methods for sperm chromosome analysis can be time-consuming and complex.

Purpose of the Study:

• To develop and validate a rapid, dual-color Primed in situ (PRINS) labeling technique for direct disomy rate estimation in human sperm.
• To assess the incidence of disomy for multiple chromosomes in sperm from fertile men.
• To investigate potential interchromosomal differences in nondisjunction rates.

Main Methods:

• Combined PRINS with NaOH pretreatment for simultaneous sperm nuclear decondensation and denaturation.
• Developed a dual-color PRINS assay for simultaneous detection of two chromosomes.
• Analyzed sperm samples from six normal fertile men, assessing disomy for 15 autosomes and sex chromosomes.

Main Results:

• Achieved simultaneous double labeling of human sperm within a 2-hour timeframe.
• Estimated disomy frequencies ranging from 0.28% to 0.36% across analyzed chromosomes.
• Observed no significant interchromosomal differences in disomy rates, except for a higher incidence of nondisjunction for chromosome 21.

Conclusions:

• The developed dual-color PRINS method offers a rapid and efficient approach for human sperm disomy assessment.
• The findings provide baseline data on disomy rates in fertile men, highlighting chromosome 21 as a potential hotspot for nondisjunction.
• This technique has implications for research into male infertility and aneuploidy.