Human Reproduction, Vol. 16, No. 7, 1449-1456,
July 2001
© 2001 European Society of Human Reproduction and Embryology
Differential gene expression in pre-implantation embryos from mouse oocytes injected with round spermatids or spermatozoa
Unité de Maturation Gamétique et Fécondation, INSERM and Institut Fédératif de Recherche sur les Cytokines, Clamart, France
BACKGROUND: The use of immature male germ cells to fertilize human oocytes raises several questions. Spermatozoa are normally quiescent, but many genes are transcribed post-meiotically in round spermatids. This creates a novel situation for the oocyte. We have therefore explored the effects on early embryonic development of introducing a fully transcriptionally active round spermatid into the oocyte. METHODS AND RESULTS: Following the micro-injection of spermatozoa or spermatids into mouse oocytes we have analysed the expression, at various times, of six genes in the resulting embryo. Spermatozoa and spermatids produced similar fertilization rates. Hprt was expressed in all embryos at all stages tested. Hsp70.1 was found normally during the 2-cell stage and repressed by the 4-cell stage in embryos from both spermatozoa and round spermatids. However, the amplitude of the signal was greatly reduced in 2-cell embryos from round spermatids. Smcy also showed a disturbed pattern of expression in embryos from round spermatids. Protamine 2, which is normally restricted to the spermatid stage, was expressed following fertilization with round spermatids, but was already repressed at the two pronuclei stage. Ube1Y, which is normally expressed post-meiotically and not during the post-implantatory development, was expressed up to the 2-cell stage in embryos from round spermatids only, and then repressed. Ube1X was also expressed up to the 2-cell stage, but in both embryo types. CONCLUSIONS: We therefore suspect that in embryos fertilized with round spermatids, regulatory mechanisms for inhibiting the inappropriate transcription of male post-meiotically expressed genes are activated following fertilization, permitting the zygotic genome activation to occur, though with some disturbances.
Key words: pre-implantation/round spermatids/spermatozoa
1 To whom correspondence should be addressed at: INSERM U 418, Communications Cellulaires et Différenciation, Hopital Debrousse, 29 rue S
ur Bouvier, 69322, Lyon, France. E-mail: lefevre{at}lyon151.inserm.fr
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  N. Nikolettos, B. Asimakopoulos, and I. S. Papastefanou Intracytoplasmic Sperm Injection-An Assisted Reproduction Technique That Should Make Us Cautious About Imprinting Deregulation Reproductive Sciences, July 1, 2006; 13(5): 317 - 328. [Abstract] [PDF]
|
|
|
|
 |
|
 L. Hewitson Primate models for assisted reproductive technologies Reproduction, September 1, 2004; 128(3): 293 - 299. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 S. Hayashi, J. Yang, L. Christenson, R. Yanagimachi, and N. B. Hecht Mouse Preimplantation Embryos Developed from Oocytes Injected with Round Spermatids or Spermatozoa Have Similar but Distinct Patterns of Early Messenger RNA Expression Biol Reprod, October 1, 2003; 69(4): 1170 - 1176. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. Ogonuki, H. Tsuchiya, Y. Hirose, H. Okada, A. Ogura, and T. Sankai Pregnancy by the tubal transfer of embryos developed after injection of round spermatids into oocyte cytoplasm of the cynomolgus monkey (Macaca fascicularis) Hum. Reprod., June 1, 2003; 18(6): 1273 - 1280. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. De Rycke, I. Liebaers, and A. Van Steirteghem Epigenetic risks related to assisted reproductive technologies: Risk analysis and epigenetic inheritance Hum. Reprod., October 1, 2002; 17(10): 2487 - 2494. [Abstract] [Full Text] [PDF]
|
|