Nani Thaís Furtado, Schnable James C, Washburn Jacob D, Albert Patrice, Pereira Welison Andrade, Sobrinho Fausto Souza, Birchler James A, Techio Vânia Helena
Department of Biology, Federal University of Lavras, Lavras, Minas Gerais State, Brazil.
University of Nebraska Lincoln, Lincoln, NE, USA.
Mol Biol Rep. 2018 Apr;45(2):109-118. doi: 10.1007/s11033-018-4144-5. Epub 2018 Jan 12.
Repetitive DNA sequences have been widely used in cytogenetic analyses. The use of gene sequences with a low-copy-number, however, is little explored especially in plants. To date, the karyotype details in Brachiaria spp. are limited to the location of rDNA sites. The challenge lies in developing new probes based on incomplete sequencing data for the genus or complete sequencing of related species, since there are no model species with a sequenced genome in Brachiaria spp. The present study aimed at the physical location of conserved genes in chromosomes of Brachiaria ruziziensis, Brachiaria brizantha, and Brachiaria decumbens using RNAseq data, as well as sequences of Setaria italica and Sorghum bicolor through the fluorescent in situ hybridization technique. Five out of approximately 90 selected sequences generated clusters in the chromosomes of the species of Brachiaria studied. We identified genes in synteny with 5S and 45S rDNA sites, which contributed to the identification of chromosome pairs carrying these genes. In some cases, the species of Brachiaria evaluated had syntenic segments conserved across the chromosomes. The use of genomic sequencing data is essential for the enhancement of cytogenetic analyses.
重复DNA序列已广泛应用于细胞遗传学分析。然而，低拷贝数基因序列的应用，尤其是在植物中的应用，却鲜有探索。迄今为止，臂形草属物种的核型细节仅限于核糖体DNA（rDNA）位点的定位。由于臂形草属没有基因组已测序的模式物种，因此面临的挑战在于基于该属不完整的测序数据或相关物种的全基因组测序来开发新的探针。本研究旨在利用RNA测序数据以及通过荧光原位杂交技术利用粟（Setaria italica）和高粱（Sorghum bicolor）的序列，确定鲁齐兹臂形草（Brachiaria ruziziensis）、俯仰臂形草（Brachiaria brizantha）和俯仰臂形草（Brachiaria decumbens）染色体上保守基因的物理位置。在所研究臂形草属物种的染色体中，大约90个选定序列中有5个产生了聚类。我们鉴定出与5S和45S rDNA位点同线的基因，这有助于识别携带这些基因的染色体对。在某些情况下，所评估的臂形草属物种在整个染色体上具有保守的同线区段。基因组测序数据的使用对于增强细胞遗传学分析至关重要。
