Germline-specific reprogramming in cloned mice

克隆小鼠种系特异性重编程

基本信息

批准号：
7065598
负责人：
John R MCCARREY
金额：
$ 45.79万
依托单位：
UNIVERSITY OF TEXAS SAN ANTONIO
依托单位国家：
美国
项目类别：
财政年份：
2002
资助国家：
美国
起止时间：
2002-06-01 至 2008-11-30
项目状态：
已结题

项目摘要

DESCRIPTION (provided by applicant): In both male and female mammals, gametogenesis is a complex process that includes genetic and epigenetic programming mechanisms that prepare the gametic genomes to direct development of an ensuing embryo. When a cloned individual is produced by transfer of a somatic cell nucleus into an enucleated egg, the donor genome has NOT undergone any of the reprogramming processes unique to gametogenesis. Thus the transplanted somatic cell nucleus must respond to signals from the recipient ooplasm directing it to undergo rapid reprogramming to facilitate embryonic development. In recent studies the extent of epigenetic reprogramming in somatic cells of cloned mice has been partially analyzed, and found to be incomplete and highly variable. However, no studies have been carried out to determine the extent to which epigenetic programming is restored in germ cells of cloned mice. Furthermore, there have been no previous studies of genetic programming in any cell type in cloned mice. In this application, we propose a systematic study to compare the extent to which genetic and epigenetic parameters become properly reprogrammed in somatic and germ cells of embryos and offspring produced by cloning via the nuclear transfer (NT) method. Only a small proportion (less than 2-3%) of cloned embryos develop to term, and only a subset of these grow into fertile adults. We hypothesize that while genetic and epigenetic programming is variable and incomplete in somatic cells of cloned mice, it can be largely restored in the germline of these individuals. We further suspect that for a cloned embryo to develop normally, the donor nucleus must undergo rapid preprogramming of epigenetic mechanisms with a low frequency of mutations. Finally, we suspect that nuclei from somatic cells and germ cells differ in their initial states of genetic and epigenetic programming and hence in their ability to successfully direct embryonic development following NT. The results of these experiments will contribute to two general areas of interest. First, they will allow us to better understand how germline-specific mechanisms of genetic and epigenetic reprogramming normally function. Second, they will provide important new insight into the efficacy and safety of mammalian cloning.

描述（由申请人提供）：在雄性和雌性哺乳动物中，配子发生都是一个复杂的过程，包括准备配子基因组以指导随后胚胎发育的遗传和表观遗传编程机制。当通过将体细胞核转移到去核卵中产生克隆个体时，供体基因组并未经历配子发生特有的任何重编程过程。因此，移植的体细胞核必须对来自受体卵质的信号做出反应，引导其进行快速重编程以促进胚胎发育。在最近的研究中，对克隆小鼠体细胞表观遗传重编程的程度进行了部分分析，发现其不完整且高度可变。然而，尚未进行任何研究来确定克隆小鼠生殖细胞中表观遗传编程的恢复程度。此外，之前还没有对克隆小鼠的任何细胞类型的遗传编程进行过研究。在本申请中，我们提出了一项系统研究，以比较通过核移植（NT）方法克隆产生的胚胎和后代的体细胞和生殖细胞中遗传和表观遗传参数正确重新编程的程度。只有一小部分（少于 2-3%）的克隆胚胎发育至足月，并且其中只有一小部分能长成具有生育能力的成体。我们假设，虽然克隆小鼠体细胞中的遗传和表观遗传编程是可变的且不完整的，但它可以在这些个体的种系中很大程度上恢复。我们进一步怀疑，为了使克隆胚胎正常发育，供体核必须经历低频率突变的表观遗传机制的快速预编程。最后，我们怀疑体细胞和生殖细胞的细胞核在遗传和表观遗传编程的初始状态上有所不同，因此在 NT 后成功指导胚胎发育的能力也有所不同。这些实验的结果将有助于两个普遍感兴趣的领域。首先，它们将使我们更好地了解遗传和表观遗传重编程的种系特异性机制如何正常发挥作用。其次，它们将为哺乳动物克隆的功效和安全性提供重要的新见解。

项目成果

期刊论文数量（6）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

Maintenance of genetic integrity during natural and assisted reproduction.

在自然和辅助生殖过程中维持遗传完整性。

DOI：
10.1016/s1472-6483(10)60449-x
发表时间：
2009
期刊：
Reproductive biomedicine online
影响因子：
4
作者：
McCarrey,JohnR
通讯作者：
McCarrey,JohnR

Adult mice cloned from migrating primordial germ cells.

DOI：
10.1073/pnas.0504943102
发表时间：
2005-08
期刊：
Proceedings of the National Academy of Sciences of the United States of America
影响因子：
11.1
作者：
Y. Yamazaki;Eleanor W. Low;Y. Marikawa;K. Iwahashi;M. Bartolomei;J. McCarrey;R. Yanagimachi
通讯作者：
Y. Yamazaki;Eleanor W. Low;Y. Marikawa;K. Iwahashi;M. Bartolomei;J. McCarrey;R. Yanagimachi