Staginnus C, Winter P, Desel C, Schmidt T, Kahl G
Plant Molecular Biology, Biocenter, University of Frankfurt, Frankfurt (M.), Germany.
Plant Mol Biol. 1999 Mar;39(5):1037-50. doi: 10.1023/a:1006125430386.
Three major repetitive DNA sequences were isolated from a genomic library of chickpea (Cicer arietinum L.) and characterized with respect to their genomic organization and chromosomal localization. All repetitive elements are genus-specific and mostly located in the AT-rich pericentric heterochromatin. Two families are organized as satellite DNAs with repeat lengths of 162-168 bp (CaSat1) and 100 bp (CaSat2). CaSat1 is mainly located adjacent to the 18S rDNA clusters on chromosomes A and B, whereas CaSat2 is a major component of the pericentric heterochromatin on all chromosomes. The high abundance of these sequences in closely related species of the genus Cicer as well as their variation in structure and copy number among the annual species provide useful tools for taxonomic studies. The retrotransposon-like sequences of the third family (CaRep) display a more complex organization and are represented by two independent sets of clones (CaRep1 and CaRep2) with homology to different regions of Ty3-gypsy-like retrotransposons. They are distributed over the pericentric heterochromatin block on all chromosomes with extensions into euchromatic regions. Conserved structures within different crossability groups of related Cicer species suggest independent amplification or transposition events during the evolution of the annual species of the genus.
从鹰嘴豆（Cicer arietinum L.）的基因组文库中分离出三种主要的重复DNA序列，并对其基因组组织和染色体定位进行了表征。所有重复元件都是属特异性的，主要位于富含AT的着丝粒周围异染色质中。两个家族被组织成卫星DNA，重复长度分别为162 - 168 bp（CaSat1）和100 bp（CaSat2）。CaSat1主要位于A和B染色体上18S rDNA簇的相邻位置，而CaSat2是所有染色体着丝粒周围异染色质的主要组成部分。这些序列在鹰嘴豆属的近缘物种中高度丰富，以及它们在一年生物种中的结构和拷贝数变化，为分类学研究提供了有用的工具。第三个家族（CaRep）的类反转录转座子序列显示出更复杂的组织形式，由两组独立的克隆（CaRep1和CaRep2）代表，它们与Ty3 - gypsy类反转录转座子的不同区域具有同源性。它们分布在所有染色体的着丝粒周围异染色质区域，并延伸到常染色质区域。相关鹰嘴豆物种不同可杂交组内的保守结构表明，在该属一年生物种的进化过程中发生了独立的扩增或转座事件。
