Targeted inactivation of the mouse epididymal beta-defensin 41 alters sperm flagellar beat pattern and zona pellucida binding

Research output: Contribution to journalArticle


During epididymal maturation, sperm acquire the ability to swim progressively by interacting with proteins secreted by the epididymal epithelium. Beta-defensin proteins, expressed in the epididymis, continue to regulate sperm motility during capacitation and hyperactivation in the female reproductive tract. We characterized the mouse beta-defensin 41 (DEFB41), by generating a mouse model with iCre recombinase inserted into the first exon of the gene. The homozygous Defb41iCre/iCre knock-in mice lacked Defb41 expression and displayed iCre recombinase activity in the principal cells of the proximal epididymis. Heterozygous Defb41iCre/+ mice can be used to generate epididymis specific conditional knock-out mouse models. Homozygous Defb41iCre/iCre sperm displayed a defect in sperm motility with the flagella primarily bending in the pro-hook conformation while capacitated wild-type sperm more often displayed the anti-hook conformation. This led to a reduced straight line motility of Defb41iCre/iCre sperm and weaker binding to the oocyte. Thus, DEFB41 is required for proper sperm maturation.


  • Ida Björkgren
  • Luis Alvarez
  • Nelli Blank
  • Melanie Balbach
  • Heikki Turunen
  • Teemu Daniel Laajala
  • Jussi Toivanen
  • Anton Krutskikh
  • Niklas Wahlberg
  • Ilpo Huhtaniemi
  • Matti Poutanen
  • Dagmar Wachten
  • Petra Sipilä
External organisations
  • University of California, Berkeley
  • Center of advanced european studies and research
  • University of Turku
  • University of Helsinki
  • Imperial College London
  • University of Gothenburg
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Zoology


  • Beta-defensin, Epididymis, Flagellar motility pattern, ICre knock-in, Sperm maturation, Sperm-oocyte binding
Original languageEnglish
Pages (from-to)143-154
Number of pages12
JournalMolecular and Cellular Endocrinology
Publication statusPublished - 2016 May 15
Publication categoryResearch