Molecular cytogenetic studies on the evolution of genome structure in reptiles and birds.

爬行动物和鸟类基因组结构进化的分子细胞遗传学研究。

基本信息

批准号：
15370001
负责人：
MATSUDA Yoichi
金额：
$ 9.6万
依托单位：
Hokkaido University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2005
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-15370001/
关键词：
chicken turtle snake crocodile FISH chromosome map conserved linkage homology sex chromosome 鳥類爬虫類 ESTクローン FISH 比較染色体地図系統進化

项目摘要

To clarify the process of karyotypic evolution and the origins of sex chromosomes and microchromosomes in birds and reptiles, we constructed chromosome maps of Chinese soft-shelled turtle, Japanese four-striped rat snake and Siam crocodile with 79, 105 and 85 functional genes, respectively. The comparative mapping between chicken and three reptile species suggests the followings : 1) the karyotypes of the common ancestor of the Archsauromorh were shared between birds and turtles, 2) chromosome rearrangements by centromeric fusion occurred at a level of whole genome in the lineage of crocodiles after centric fission of chromosomes 1 and 2 of the common ancestor, 3) the intermediate karyotypes between the common ancestor and the crocodiles might have been conserved in the lineage of caimans, and 4) in the Lepidosauria high frequencies of chromosome rearrangements occurred independently from the Archosauromorph.We cloned reptile homologues of six chicken Z-linked genes, ACO1, ATP5A1, CHD1, DMRT1, GHR and RPS6, from the turtle and the snake with ZZ/ZW-type sex chromosomes and the crocodile with undifferentiated sex chromosomes, and mapped them to the chromosomes of the three species. All the genes were localized to the long arm of the turtle chromosome 6, the short arm of the snake chromosome 2 and the short arm of the crocodile chromosome 3. These results indicate that the genetic linkage on chicken Z chromosome has been highly conserved in reptiles, and that the causative genes of sex determination may be different between birds and reptiles.

为了阐明鸟类和爬行动物的核型进化过程以及性染色体和微染色体的起源，我们构建了中华鳖、日本四纹鼠蛇和暹罗鳄的染色体图谱，分别包含79、105和85个功能基因。鸡和三种爬行动物之间的比较图谱表明：1）鸟类和乌龟共享Archsauromorh共同祖先的核型，2）在鳄鱼谱系中，通过着丝粒融合发生的染色体重排发生在整个基因组水平上共同祖先的 1 号和 2 号染色体发生中心裂变后，3）共同祖先和鳄鱼之间的中间核型可能是凯门鳄谱系中保守，4）在鳞龙目中，独立于主龙形体发生高频率的染色体重排。我们从爬行动物中克隆了六个鸡 Z 连锁基因 ACO1、ATP5A1、CHD1、DMRT1、GHR 和 RPS6 的同源物。具有ZZ/ZW型性染色体的乌龟和蛇以及具有未分化性染色体的鳄鱼，并绘制了它们的图谱到三个物种的染色体。所有基因均定位于龟6号染色体的长臂、蛇2号染色体的短臂和鳄鱼3号染色体的短臂。这些结果表明鸡Z染色体上的遗传连锁在爬行动物中高度保守，并且鸟类和爬行动物之间性别决定的致病基因可能不同。