Freeze-dried sperm fertilization leads to full-term development in rabbits

Biol Reprod. 2004 Jun;70(6):1776-81. doi: 10.1095/biolreprod.103.025957. Epub 2004 Feb 11.

Abstract

To date, the laboratory mouse is the only mammal in which freeze-dried spermatozoa have been shown to support full-term development after microinjection into oocytes. Because spermatozoa in mice, unlike in most other mammals, do not contribute centrosomes to zygotes, it is still unknown whether freeze-dried spermatozoa in other mammals are fertile. Rabbit sperm was selected as a model because of its similarity to human sperm (considering the centrosome inheritance pattern). Freeze- drying induces rabbit spermatozoa to undergo dramatic changes, such as immobilization, membrane breaking, and tail fragmentation. Even when considered to be "dead" in the conventional sense, rabbit spermatozoa freeze-dried and stored at ambient temperature for more than 2 yr still have capability comparable to that of fresh spermatozoa to support preimplantation development after injection into oocytes followed by activation. A rabbit kit derived from a freeze-dried spermatozoon was born after transferring 230 sperm-injected oocytes into eight recipients. The results suggest that freeze-drying could be applied to preserve the spermatozoa from most other species, including human. The present study also raises the question of whether rabbit sperm centrosomes survive freeze-drying or are not essential for embryonic development.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Embryo Transfer
  • Embryonic Development
  • Female
  • Freeze Drying
  • Humans
  • Male
  • Mice
  • Microscopy, Confocal
  • Microscopy, Electron, Scanning
  • Models, Animal
  • Oocytes / drug effects
  • Oocytes / growth & development
  • Pregnancy
  • Rabbits
  • Semen Preservation / methods*
  • Sperm Injections, Intracytoplasmic
  • Spermatozoa / ultrastructure