Related Experiment Video

Updated: Jul 2, 2026

Medium-throughput Screening Assays for Assessment of Effects on Ca2+-Signaling and Acrosome Reaction in Human Sperm
05:44

Medium-throughput Screening Assays for Assessment of Effects on Ca2+-Signaling and Acrosome Reaction in Human Sperm

Published on: March 1, 2019

Src activation triggers capacitation and acrosome reaction but not motility in human spermatozoa

Gabriele Varano1, Adriana Lombardi, Giulia Cantini

  • 1Department of Clinical Physiopathology, Endocrinology Unit, DENOTHE Center for Research, Transfer and High Education, University of Florence, Florence, Italy.

Human Reproduction (Oxford, England)
|August 30, 2008
PubMed
Abstract

Insights

Src kinase plays a key role in human sperm activation. This study identifies its presence and function in regulating sperm capacitation, tyrosine phosphorylation, and the acrosome reaction, crucial for male fertility.

Area of Science:

  • Reproductive Biology
  • Molecular Cell Biology
  • Sperm Physiology

Background:

  • Protein tyrosine phosphorylation is vital for sperm activation.
  • The roles of tyrosine kinases in sperm function remain largely unknown.
  • Src kinase presence and function in human spermatozoa were investigated.

Purpose of the Study:

  • To identify and localize Src kinase in human spermatozoa.
  • To investigate the role of Src kinase in sperm activation processes.
  • To determine Src kinase's involvement in capacitation, tyrosine phosphorylation, and acrosome reaction.

Main Methods:

  • Immunodetection and immunoprecipitation using anti-Src antibodies.
  • Immunofluorescence to determine Src kinase localization and active form (pTyr416).
  • Pharmacological inhibition of Src kinase using SU6656 to assess functional impact.

Main Results:

  • Src kinase (approx. 70 kDa) localized to the post-acrosomal region, neck, and midpiece.
  • Active Src kinase levels increased during sperm capacitation.
  • Src kinase inhibition reduced tyrosine phosphorylation, blocked progesterone-induced acrosome reaction, and interfered with calcium signaling.

Conclusions:

  • A novel Src isoform is identified in human spermatozoa.
  • Src kinase is involved in regulating sperm capacitation and tyrosine phosphorylation.
  • Src kinase plays a critical role in calcium fluxes and the acrosome reaction.

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