Structure and size variations between 12A and 12D homoeologous chromosomes based on high-resolution cytogenetic map in allotetraploid cotton
Structure and size variations between 12A and 12D homoeologous chromosomes based on high-resolution cytogenetic map in allotetraploid cotton
复制标题
基于异源四倍体棉花高分辨率细胞遗传学图谱的12A和12D同源染色体的结构和大小变异
DOI：
10.1007/s00412-009-0254-0
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发表时间：
2010-06-01
期刊：
影响因子：
1.6
通讯作者：
Zhang, Tianzhen
中科院分区：
文献类型：
--
作者：
Wang, Kai;Guo, Wangzhen;Zhang, Tianzhen
棉花是研究多倍化、基因组组织和基因组大小变异的模型系统，因为异源四倍体形成于1-2百万年前，这对于序列分歧来说足够古老，但相对较近，以维持基因组稳定性。尽管在许多多倍体植物中描述了随机基因组序列的特征，但在异源多倍体物种中破译同源染色体的细胞遗传学和序列数据非常有限。本文报道了利用荧光原位杂交技术和大量的细菌人工染色体对异源四倍体棉花同源染色体12 A和12 D的整合细胞遗传学和连锁图谱的综合分析。整合到物理定位的遗传位点表现出相当大的变化，基因组的组织，结构和大小之间的12 A和12 D同源染色体。染色体的远端区域显示出比染色体的其他区域相对较低水平的结构和大小变异。最高水平的变化被发现在两个同源染色体的长臂的臂间区域。异源四倍体棉花A、D亚基因组大小的差异主要与同源染色体不同区域的不均匀伸缩有关。这些结果对植物多倍体同源染色体的研究是一个尝试，对了解植物复杂基因组和将来的基因组测序具有普遍意义。
Cotton is a model system for studying polyploidization, genomic organization, and genome-size variation because the allotetraploid was formed 1-2 million years ago, which is old enough for sequence divergence but relatively recent to maintain genome stability. In spite of characterizing random genomic sequences in many polyploidy plants, the cytogenetic and sequence data that decipher homoeologous chromosomes are very limited in allopolyploid species. Here, we reported comprehensive analyses of integrated cytogenetic and linkage maps of homoeologous chromosomes 12A and 12D in allotetraploid cotton using fluorescence in situ hybridization and a large number of bacterial artificial chromosomes that were anchored by simple sequence repeat markers in the corresponding linkage maps. Integration of genetic loci into physical localizations showed considerable variation of genome organization, structure, and size between 12A and 12D homoeologous chromosomes. The distal regions of the chromosomes displayed relatively lower levels of structural and size variation than other regions of the chromosomes. The highest level of variation was found in the pericentric regions in the long arms of the two homoeologous chromosomes. The genome-size difference between A and D sub-genomes in allotetraploid cotton was mainly associated with uneven expansion or contraction between different regions of homoeologous chromosomes. As an attempt for studying on the polyploidy homoeologous chromosomes, these results are of general interest to the understanding and future sequencing of complex genomes in plant species.