Different Nuclear Architecture in Human Sperm According to Their Morphology

Area of Science:

• Reproductive Biology
• Spermatozoa Morphology
• Chromosomal Analysis

Background:

• Standard human sperm parameters are insufficient for predicting pregnancy success in assisted reproductive technologies (ARTs).
• Sperm head morphology assessed by high magnification offers potential insights beyond basic infertility diagnosis.

Purpose of the Study:

• To investigate the correlation between detailed sperm head morphology and nuclear architecture in human spermatozoa.
• To determine if nuclear parameters assessed by fluorescence in situ hybridization (FISH) differ between men with high and low sperm morphology scores.

Main Methods:

• Utilized fluorescence in situ hybridization (FISH) to analyze the inter-telomeric distance (ITD) and chromosomal territory area (CTA) of chromosome 1 (Chr. 1).
• Compared FISH-derived nuclear parameters in spermatozoa from men with high (score 6) versus low (score 0) high-magnification morphology scores.

Main Results:

• Significantly higher ITD and CTA of Chr. 1 were observed in subjects with low sperm morphology scores (score 0) compared to those with high scores (score 6).
• These findings suggest a relationship between sperm head abnormalities, such as vacuoles, and altered nuclear architecture.

Conclusions:

• Sperm nuclear architecture is linked to sperm head morphology, particularly the presence of vacuoles.
• Selecting spermatozoa with normal nuclear architecture may indirectly contribute to positive outcomes in ART procedures.