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The shape of the sperm midpiece in intracytoplasmic morphologically selected sperm injection relates sperm

Tomohisa Ugajin1, Yukihiro Terada, Hisataka Hasegawa

  • 1Department of Obstetrics and Gynecology, Tohoku University School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai, Miyagi 980-8574, Japan.

Journal of Assisted Reproduction and Genetics
|December 17, 2009
PubMed
Abstract

Insights

Selecting sperm with straight midpieces significantly improves sperm aster formation rates. This finding suggests that midpiece morphology is crucial for sperm centrosomal function and successful fertilization via intracytoplasmic sperm injection (ICSI).

Area of Science:

  • Reproductive Biology
  • Spermatozoa Morphology
  • Cell Biology

Background:

  • Sperm centrosomal function is critical for successful fertilization.
  • The relationship between sperm midpiece morphology and centrosomal function requires further investigation.
  • High magnification microscopy offers detailed insights into sperm structure.

Purpose of the Study:

  • To determine if sperm midpiece morphology, as observed under high magnification microscopy, correlates with sperm centrosomal function.
  • To assess the impact of specific midpiece morphologies on sperm aster formation.
  • To evaluate the potential of morphological selection for improving assisted reproductive technologies.

Main Methods:

  • Sperm were categorized into control, straight midpiece (Group 1), and tapering midpiece (Group 2) groups using high magnification microscopy.
  • Sperm centrosomal function was assessed through heterologous intracytoplasmic sperm injection (ICSI) into bovine oocytes.
  • Sperm aster formation was analyzed as a key indicator of centrosomal function.

Main Results:

  • Sperm with straight midpieces (Group 1) exhibited a significantly higher rate of aster formation (80.5%) compared to those with tapering midpieces (Group 2, 33.3%) (P < 0.05).
  • Group 1 sperm also showed a trend towards higher aster formation rates than the control group.
  • These results indicate a strong link between straight midpiece morphology and robust centrosomal function.

Conclusions:

  • Selecting sperm based on straight midpiece morphology enhances sperm aster formation rates.
  • Utilizing sperm with morphologically straight midpieces for ICSI may improve sperm centrosomal function.
  • This morphological selection strategy holds promise for enhancing fertilization outcomes in ICSI procedures.

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