HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 70/6/1863    most recent biolreprod.103.025171v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal My Folders Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Kishigami, S. Articles by Wakayama, T. Search for Related Content PubMed PubMed Citation Articles by Kishigami, S. Articles by Wakayama, T. Agricola Articles by Kishigami, S. Articles by Wakayama, T.

Similar Time Restriction for Intracytoplasmic Sperm Injection and Round Spermatid Injection into Activated Oocytes for Efficient Offspring Production¹

Laboratory for Genome Reprogramming, RIKEN Center for Developmental Biology, Kobe, Hyogo 650-0047, Japan

The injection of male haploid germ cells, such as spermatozoa and round spermatids, into preactivated mouse oocytes can result in the development of viable embryos and offspring. However, it is not clear how the timing of intracytoplasmic sperm injection (ICSI) and round spermatid injection (ROSI) affects the production of offspring. We carried out ICSI and ROSI every 20 min for up to 4 h after the activation of mouse oocytes by Sr²⁺ and compared the late-stage development of ICSI- and ROSI- treated oocytes, including the formation of pronuclei, blastocyst formation, and offspring production. The rate of pronucleus formation (RPF) after carrying out ICSI started to decrease from >95% at 100 min following oocyte activation and declined to <20% by 180 min. In comparison, RPF by ROSI decreased gradually from >70% between 0 and 4 h after activation. The RPFs were closely correlated with blastocyst formation. Offspring production for both ICSI and ROSI decreased significantly when injections were conducted after 100 min, a time at which activated oocytes were in the early G1 stage of the cell cycle. These results suggest that spermatozoa and round spermatids have different potentials for inducing the formation of a male pronucleus in activated oocytes, but ICSI and ROSI are both subject to the same time constraint for the efficient production of offspring, which is determined by the cell cycle of the activated oocyte.

¹ Supported by grants-in-aid for Creative Scientific Research (13GS0008) and to Young Scientists (A) (15681014) to T.W. from MEXT, Japan.

² Correspondence: Satoshi Kishigami, RIKEN Center for Developmental Biology, 2-2-3, Minatojima Minamimachi, Chuo-ku, Kobe, Hyogo 650- 0047, Japan. FAX: 81 78 306 3095; kishigami{at}cdb.riken.jp

This article has been cited by other articles:

				K. Yamagata Capturing Epigenetic Dynamics During Pre-implantation Development Using Live Cell Imaging J. Biochem., March 1, 2008; 143(3): 279 - 286. [Abstract] [Full Text] [PDF]

				J. Loren and O. Lacham-Kaplan The employment of strontium to activate mouse oocytes: effects on spermatid-injection outcome Reproduction, February 1, 2006; 131(2): 259 - 267. [Abstract] [Full Text] [PDF]