Analysis of BAC clones containing homologous sequences on the end of the Xq arm and on chromosome 7 in the dioecious plant Silene latifolia
Analysis of BAC clones containing homologous sequences on the end of the Xq arm and on chromosome 7 in the dioecious plant Silene latifolia
复制标题
DOI：
10.1139/g10-008
复制
发表时间：
2010-04-01
期刊：
影响因子：
3.1
通讯作者：
Kawano, Shigeyuki
中科院分区：
文献类型：
--
作者：
Ishii, Kotaro;Amanai, Yasuhito;Kawano, Shigeyuki
宽叶硅烯是一种雌雄异株的模式植物，具有形态上可区分的XY性染色体。XQ臂的末端与YP臂的末端非常不同，尽管它们都位于各自染色体的相对假常染色体区域的两端。XQ臂似乎与YP臂不是来自同一常染色体。细菌人工染色体克隆#15B12有一个130kb的插入片段，其中313bp的卫星DNA重复420次。用单一引物进行的聚合酶链式反应显示，这条130kb的片段由卫星DNA方向的三个反转组成。在卫星DNA两侧的序列中发现了一个非长末端重复序列反转录元件和两个分别与水稻环状锌指蛋白和拟南芥蛋白同源的序列。以#15B12的低拷贝区域为探针进行荧光原位杂交，证实这些序列起源于X染色体，在7号染色体末端存在同源序列。推测在性染色体进化过程中，XQ臂上的DD44X远端区域与7号染色体上含有卫星DNA的区域发生了重组。
Silene latifolia is a model dioecious plant with morphologically distinguishable XY sex chromosomes. The end of the Xq arm is quite different from that of the Yp arm, although both are located at opposite ends of their respective chromosomes relative to a pseudo-autosomal region. The Xq arm does not seem to originate from the same autosome as the Yp arm. Bacterial artificial chromosome clone #15B12 has an insert containing a 130-kb stretch in which a 313-bp satellite DNA is repeated 420 times. PCR with a single primer revealed that this 130-kb stretch consists of three reversals of the orientation of the satellite DNA. A non-long terminal repeat retroelement and two sequences that share homology with an Oryza sativa RING zinc finger and a putative Arabidopsis thaliana protein, respectively, were found in the sequences that flank the satellite DNA. Fluorescence in situ hybridization carried out using this low-copy region of #15B12 as a probe confirmed that these sequences originated from the X chromosome and that homologous sequences exist at the end of chromosome 7. The region distal to DD44X on the Xq arm is postulated to have recombined with a region containing satellite DNA on chromosome 7 during the process of sex chromosome evolution.