Cell Fusion pp 335-345 | Cite as

Sperm–Egg Fusion Assay in Mammals

  • Naokazu Inoue
  • Masaru Okabe
Part of the Methods in Molecular Biology™ book series (MIMB, volume 475)


As representatives of the 60 trillion cells that make a human body, a sperm and an egg meet, recognize each other, and fuse to create a new generation. Thus, gamete fusion is an extremely important process that must transpire without error to launch life activity. This may drive the fusion mechanism to evolve into an unfailing and steady process. At the same time, fusion must be restricted to occur only between two gametes of the same species. However, the molecular bases of the fusion event in fertilization have not yet been clarified. In this chapter, we describe the methods to evaluate fusion by staining the swollen sperm nuclei after fertilization.

Key Words:

Sperm; egg; fusion; fertilization; Izumo. 


  1. 1.
    Inoue, N., Ikawa, M., Isotani, A., and Okabe M. (2005) The immunoglobulin super-family protein Izumo is required for sperm to fuse with eggs. Nature 434 , 234–238.CrossRefPubMedGoogle Scholar
  2. 2.
    Le Naour, F., Rubinstein, E., Jasmin, C., Prenant, M., and Boucheix, C. (2000) Severely reduced female fertility in CD9-deficient mice. Science 287 , 329–321.CrossRefGoogle Scholar
  3. 3.
    Miyado, K., Yamada, G., Yamada, S., Hasuwa, H., Nakamura, Y., Ryu, F., Suzuki, K., Kosai, K., Inoue, K., Ogura, A., Okabe, M., and Mekada, E. (2000) Requirement of CD9 on the egg plasma membrane for fertilization. Science 287 , 321–324.CrossRefPubMedGoogle Scholar
  4. 4.
    Kaji, K., Oda, S., Shikano, T., Ohnuki, T., Uematsu, T., Sakagami, J., Tada, N., Miyazaki, S., and Kudo, A. (2000) The gamete fusion process is defective in eggs of Cd9-deficient mice. Nat. Genet. 24 , 279–282.CrossRefPubMedGoogle Scholar
  5. 5.
    Nagy, A., Gertsenstein, M., Vintersten, K., and Behringer, R. (2002) Manipulating the Mouse Embryo, 3rd ed. Cold Spring Harbor Laboratory Press, Cold Spring Harbor, NY.Google Scholar
  6. 6.
    Yamagata, K., Nakanishi, T., Ikawa, M., Yamaguchi, R., Moss, S, B., and Okabe, M. (2002) Sperm from the calmegin-deficient mouse have normal abilities for binding and fusion to the egg plasma membrane. Dev. Biol. 250 , 348–357.PubMedGoogle Scholar
  7. 7.
    Ziyyat, A., Rubinstein, E., Monier-Gavelle, F., Barraud, V., Kulski, O., Prenant, M., Boucheix, C., Bomsel, M., and Wolf, J. P. (2006) CD9 controls the formation of clusters that contain tetraspanins and the integrin alpha 6 beta 1, which are involved in human and mouse gamete fusion. J. Cell Sci. 119 , 416–424.CrossRefPubMedGoogle Scholar
  8. 8.
    Nakanishi, T., Ikawa, M., Yamada, S., Parvinen, M., Baba, T., Nishimune, Y., and Okabe, M. (1999) Real-time observation of acrosomal dispersal from mouse sperm using GFP as a marker protein. FEBS Lett. 449 , 277–283.CrossRefPubMedGoogle Scholar

Copyright information

© Humana Press, a part of Springer Science + Business Media, LLC 2008

Authors and Affiliations

  • Naokazu Inoue
    • 1
  • Masaru Okabe
    • 1
  1. 1.Genome Information Research Center, Research Institute for Microbial DiseasesOsaka UniversityOsakaJapan

Personalised recommendations