权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Positional cloning of gene that regulates proliferation and differentiation of embronic ectoderm.

调控胚胎外胚层增殖和分化的基因的定位克隆。

基本信息

批准号：
13640616
负责人：
ABE Kuniya
金额：
$ 2.56万
依托单位：
The Institute of Physical and Chemical Research
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2002
项目状态：
已结题

项目摘要

Mice homozygous for the tw5 allele arrest at gastrulation stage from defects associated with embryonic ectoderm proliferation/differentiation. The mutated gene mapped very close to H-2K gene in mouse MHC. To positionally clone the mutated gene, a BAC contig spanning 〜1000 kb of the corresponding genomic region was constructed. Combining our own sequencing analysis data of those BAC clones and genomic data available from public database, it was determined that the size of the tw5 critical region is 750 kb. EST database search, gene prediction program analysis and an experimental expression analysis suggest that there are possibly 36 genes within this region. Based on their expression profiles, this region is extremely rich in embryonically active genes, which are candidates for the tw5 embryonic lethality.To understand the function of tclw5 gene product, we tried to determine the primary site of tclw5 gene action. Histological examination demonstrated that homozygotes of t^<w5> died at the gastrulation stage due to extensive death of the embryonic ectoderm cells while the extraembryonic ectoderm and the visceral endoderm were less affected in these embryos. By aggregation with diploid wild-type embryos, t^<w5>/t^<w5> cells were capable of contributing to all three germ layers. Thus, it is likely that tclw5 is not cell autonomous lethal. Furthermore, the hypothesis that tissues other than the embryonic ectoderm are the primary sites of tclw5 action was supported by the rescue of t^<w5>/t^<w5> embryos by aggregation with tetraploid embryos. Therefore, it is probable that the product of tclw5 is essential for the function of extraembryonic tissues.

在与胚胎外胚层增殖/分化相关的缺陷中，原肠形成阶段TW5等位基因纯合的小鼠。该突变基因与小鼠MHC中的H-2K基因非常接近。为了对突变基因进行定位克隆，构建了相应基因组区长约1000kb的BAC重叠群。结合我们对这些BAC克隆的测序分析数据和从公共数据库中获得的基因组数据，确定了tw5关键区的大小为750kb。EST数据库搜索、基因预测程序分析和实验表达分析表明，该区域可能有36个基因。根据它们的表达谱，该区域含有非常丰富的胚胎活性基因，这些基因是TW5胚胎白血病的候选基因。为了了解tclw5基因产物的功能，我们试图确定tclw5基因作用的主要位置。组织学检查表明，t^&lt；w5&gt；纯合子在原肠胚期由于胚胎外胚层细胞的广泛死亡而死亡，而胚外胚层和内脏内胚层受到的影响较小。通过与二倍体野生型胚胎的聚集，t^&lt；w5&gt；/t^&lt；w5&gt；细胞能够对所有三个胚层做出贡献。因此，tclw5很可能不是细胞自主致死的。此外，t^&lt；w5&gt；/t^&lt；w5&gt；因此，TCLW5的产物可能是胚外组织功能所必需的。