Center for Informational Biology, School of Life Science and Technology, University of Electronic Science and Technology of China, 611731, Chengdu, China.
College of Agronomy, Shanxi Agricultural University, 030801, Taigu, China.
BMC Plant Biol. 2021 May 12;21(1):213. doi: 10.1186/s12870-021-02999-3.
The identification of chromosomes among Avena species have been studied by C-banding and in situ hybridization. However, the complicated results from several cytogenetic nomenclatures for identifying oat chromosomes are often contradictory. A universal karyotyping nomenclature system for precise chromosome identification and comparative evolutionary studies would be essential for genus Avena based on the recently released genome sequences of hexaploid and diploid Avena species.
Tandem repetitive sequences were predicted and physically located on chromosomal regions of the released Avena sativa OT3098 genome assembly v1. Eight new oligonucleotide (oligo) probes for sequential fluorescence in situ hybridization (FISH) were designed and then applied for chromosome karyotyping on mitotic metaphase spreads of A. brevis, A. nuda, A. wiestii, A. ventricosa, A. fatua, and A. sativa species. We established a high-resolution standard karyotype of A. sativa based on the distinct FISH signals of multiple oligo probes. FISH painting with bulked oligos, based on wheat-barley collinear regions, was used to validate the linkage group assignment for individual A. sativa chromosomes. We integrated our new Oligo-FISH based karyotype system with earlier karyotype nomenclatures through sequential C-banding and FISH methods, then subsequently determined the precise breakage points of some chromosome translocations in A. sativa.
This new universal chromosome identification system will be a powerful tool for describing the genetic diversity, chromosomal rearrangements and evolutionary relationships among Avena species by comparative cytogenetic and genomic approaches.
通过 C 带和原位杂交技术研究了燕麦属物种的染色体鉴定。然而，几种用于鉴定燕麦染色体的细胞遗传学命名法的复杂结果往往相互矛盾。基于最近发布的六倍体和二倍体燕麦属物种基因组序列，对于燕麦属来说，建立一个用于精确染色体鉴定和比较进化研究的通用核型命名系统是必不可少的。
预测并在已发布的燕麦 sativa OT3098 基因组组装 v1 的染色体区域上定位串联重复序列。设计了 8 个新的寡核苷酸（oligo）探针，用于顺序荧光原位杂交（FISH），然后应用于 A. brevis、A. nuda、A. wiestii、A. ventricosa、A. fatua 和 A. sativa 种的有丝分裂中期分裂中期的染色体核型分析。我们基于多个 oligo 探针的独特 FISH 信号，建立了 A. sativa 的高分辨率标准核型。基于小麦-大麦共线性区域的 bulked oligos 的 FISH 绘画用于验证个别 A. sativa 染色体的连锁群分配。我们通过顺序 C-带和 FISH 方法将我们新的基于寡核苷酸的 FISH 核型系统与早期的核型命名法整合在一起，然后确定了 A. sativa 中一些染色体易位的精确断裂点。
这个新的通用染色体识别系统将通过比较细胞遗传学和基因组方法成为描述燕麦属物种遗传多样性、染色体重排和进化关系的有力工具。
