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）：在男性和女性哺乳动物中，配子发生是一个复杂的过程，其中包括遗传和表观遗传编程机制，这些机制使配子基因组制备直接开发随后的胚胎。当通过将体细胞核转移到浓缩的卵中，产生克隆的个体时，供体基因组并未经历任何对配物发生特有的重编程过程。因此，移植的体细胞核必须响应受体卵子的信号，以引导其快速重编程，以促进胚胎发育。在最近的研究中，已部分分析了克隆小鼠体细胞中表观遗传重编程的程度，发现不完整且变化很大。但是，尚未进行研究以确定克隆小鼠的生殖细胞恢复表观遗传编程的程度。此外，以前在克隆小鼠中任何细胞类型的遗传编程都没有研究。在此应用中，我们提出了一项系统的研究，以比较在胚胎和胚胎和后代通过核转移（NT）方法产生的遗传和表观遗传参数在多大程度上正确重编程的程度。克隆的胚胎只有一小部分（少于2-3％）的术语，只有一部分成年人成年。我们假设，虽然遗传和表观遗传编程在克隆小鼠的体细胞中是可变且不完整的，但可以在这些个体的种系中基本恢复。我们进一步怀疑，要使克隆的胚胎正常发育，供体核必须经过较低突变频率的表观遗传机理的快速预编程。最后，我们怀疑来自体细胞和生殖细胞的核在其遗传和表观遗传编程的初始状态下有所不同，因此在NT后成功地引导胚胎发育的能力。这些实验的结果将有助于两个关注的一般领域。首先，它们将使我们能够更好地理解遗传和表观遗传重编程的种系特异性机制通常起作用。其次，他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