Zhang Peng, Li Wanlong, Friebe Bernd, Gill Bikram S
Wheat Genetics Resources Center, Department of Plant Pathology, 4024 Throckmorton Plant Sciences Center, Kansas State University, Manhattan, KS 66506-5502, USA.
Genome. 2004 Oct;47(5):979-87. doi: 10.1139/g04-042.
Fluorescence in situ hybridization (FISH) is widely used in the physical mapping of genes and chromosome landmarks in plants and animals. Bacterial artificial chromosomes (BACs) contain large inserts, making them amenable for FISH mapping. In our BAC-FISH experiments, we selected 56 restriction fragment length polymorphism (RFLP)-locus-specific BAC clones from the libraries of Triticum monococcum and Aegilops tauschii, which are the A- and D-genome donors of wheat (Triticum aestivum, 2n = 6x = 42), respectively. The BAC clone 676D4 from the T. monococcum library contains a dispersed repeat that preferentially hybridizes to A-genome chromosomes, and two BAC clones, 9I10 and 9M13, from the Ae. tauschii library contain a dispersed repeat that preferentially hybridizes to the D-genome chromosomes. These repeats are useful in simultaneously discriminating the three different genomes in hexaploid wheat, and in identifying intergenomic translocations in wheat or between wheat and alien chromosomes. Sequencing results show that both of these repeats are transposable elements, indicating the importance of transposable elements, especially retrotransposons, in the genome evolution of wheat.
荧光原位杂交（FISH）在植物和动物的基因物理图谱绘制及染色体标记定位中被广泛应用。细菌人工染色体（BAC）含有大片段插入序列，使其适用于FISH图谱分析。在我们的BAC-FISH实验中，我们从小麦（普通小麦，2n = 6x = 42）的A基因组供体一粒小麦和D基因组供体节节麦的文库中选择了56个限制性片段长度多态性（RFLP）位点特异性BAC克隆。一粒小麦文库中的BAC克隆676D4含有一个优先与A基因组染色体杂交的分散重复序列，节节麦文库中的两个BAC克隆9I10和9M13含有一个优先与D基因组染色体杂交的分散重复序列。这些重复序列有助于同时区分六倍体小麦中的三种不同基因组，并鉴定小麦内部或小麦与外源染色体之间的基因组间易位。测序结果表明，这两种重复序列均为转座元件，表明转座元件，尤其是反转录转座子，在小麦基因组进化中具有重要作用。
