Department of Horticulture, University of Wisconsin-Madison, Wisconsin 53706.
Departmento de Biologia, Universidade Federal de Lavras, 37200, Brazil.
Genetics. 2018 Feb;208(2):513-523. doi: 10.1534/genetics.117.300344. Epub 2017 Dec 13.
Developing the karyotype of a eukaryotic species relies on identification of individual chromosomes, which has been a major challenge for most nonmodel plant and animal species. We developed a novel chromosome identification system by selecting and labeling oligonucleotides (oligos) located in specific regions on every chromosome. We selected a set of 54,672 oligos (45 nt) based on single copy DNA sequences in the potato genome. These oligos generated 26 distinct FISH signals that can be used as a "bar code" or "banding pattern" to uniquely label each of the 12 chromosomes from both diploid and polyploid (4× and 6×) potato species. Remarkably, the same bar code can be used to identify the 12 homeologous chromosomes among distantly related species, including tomato and eggplant. Accurate karyotypes based on individually identified chromosomes were established in six species that have diverged for >15 MY. These six species have maintained a similar karyotype; however, modifications to the FISH signal bar code led to the discovery of two reciprocal chromosomal translocations in and We also validated these translocations by oligo-based chromosome painting. We demonstrate that the oligo-based FISH techniques are powerful new tools for chromosome identification and karyotyping research, especially for nonmodel plant species.
开发真核生物的核型依赖于对个体染色体的识别，这对大多数非模式植物和动物物种来说一直是一个主要挑战。我们开发了一种新的染色体识别系统，通过选择和标记位于每条染色体特定区域的寡核苷酸（oligos）。我们根据马铃薯基因组中的单拷贝 DNA 序列选择了一组 54672 个 oligos（45nt）。这些 oligos 产生了 26 个不同的 FISH 信号，可以作为“条形码”或“带型”，用于独特地标记来自二倍体和多倍体（4×和 6×）马铃薯物种的 12 条染色体。值得注意的是，相同的条形码可用于鉴定远缘物种（包括番茄和茄子）之间的 12 条同源染色体。在已经分化了>15 MY 的六个物种中，基于个体识别的染色体建立了准确的核型。这六个物种保持了相似的核型；然而，FISH 信号条形码的修改导致在 和 中发现了两个相互易位的染色体。我们还通过基于寡核苷酸的染色体涂染验证了这些易位。我们证明，基于寡核苷酸的 FISH 技术是染色体识别和核型研究的强大新工具，特别是对于非模式植物物种。
