Synchronous sperm penetration of zona-free mouse eggs in vitro

Y. Takahashi, Chikara Meno, E. Sato, Y. Toyoda

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

To synchronize sperm penetration of zona-free eggs immediately after insemination, zona-free eggs preloaded with Hoechst-33342 were inseminated under various conditions. Insemination was mostly conducted at 10 sperm/μl. In preliminary experiments, fatty acid-free BSA (FAF) was more satisfactory for sperm penetration than fraction V BSA, and FAF was used in the following experiments. Only 26% of zona-free eggs were fertilized at 10 min after insemination when the eggs were inseminated immediately after zona removal and preloading. However, egg preincubation significantly improved the penetration rate (1 h preincubation: 63%, 2 h preincubation: 82% penetrated 10 min after insemination). Some eggs preincubated for 2 h were already penetrated at 3 min (7%), and the rate gradually increased in a time- dependent manner (3 min: 7%, 5 min: 30%, 10 min: 80%). The rate further improved as the sperm concentration was increased; the maximal level was obtained at 160 sperm/μl. At 160 sperm/μl, 54% of the eggs were penetrated at 3 min and 78% were at 5 min. These results indicate that it is possible to synchronize the sperm entry and that not only sperm but zona-free eggs should be preincubated before insemination. These data are considered valuable for investigating early events in fertilization.

Original languageEnglish
Pages (from-to)424-430
Number of pages7
JournalBiology of Reproduction
Volume53
Issue number2
DOIs
Publication statusPublished - Aug 30 1995
Externally publishedYes

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Sperm-Ovum Interactions
Herpes Zoster
Insemination
Eggs
Spermatozoa
Nonesterified Fatty Acids
Zygote
Fertilization
Ovum
In Vitro Techniques

All Science Journal Classification (ASJC) codes

  • Cell Biology

Cite this

Synchronous sperm penetration of zona-free mouse eggs in vitro. / Takahashi, Y.; Meno, Chikara; Sato, E.; Toyoda, Y.

In: Biology of Reproduction, Vol. 53, No. 2, 30.08.1995, p. 424-430.

Research output: Contribution to journalArticle

Takahashi, Y. ; Meno, Chikara ; Sato, E. ; Toyoda, Y. / Synchronous sperm penetration of zona-free mouse eggs in vitro. In: Biology of Reproduction. 1995 ; Vol. 53, No. 2. pp. 424-430.
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