Submitted December 6, 2007
Returned for revision December 31, 2007
Accepted January 15, 2008
Reproductive Technology
Birth of Mice after Intracytoplasmic Injection of Single Purified Sperm Nuclei and Detection of Messenger RNAs and MicroRNAs in the Sperm Nuclei
Wei Yan *,
Kazuto Morozumi ,
Jie Zhang ,
Seungil Ro ,
Chanjae Park ,
and
Ryuzo Yanagimachi
* To whom correspondence should be addressed. E-mail: wyan{at}unr.edu.
Abstract
We have developed a method which effectively removes all of the perinuclear materials of a mouse sperm head including the acrosome, plasma membrane, perinuclear theca and nuclear envelop. By injection of a single purified sperm head into a metaphase II mouse oocyte followed by activation with strontium chloride, 93% of the zygotes developed into 2-cell embryos. Although only ~17% of the transferred 2-cell embryos were born alive, all live pups developed into adults and they appeared to be normal in reproduction and behavior. We detected RNA species including mRNAs and miRNAs from the purified sperm heads. Our data demonstrate that "pure" membrane-free sperm heads are sufficient to produce normal offspring through intracytoplasmic sperm injection and that at least part of the RNA molecules are deeply embedded in the sperm nucleus.
Key words:
Embryo •
Early development •
Fertilization •
In vitro fertilization •
Sperm
