Department of Cell Biology and Genetics, University of Alcalá, 28871, Alcalá de Henares (Madrid), Spain.
Theor Appl Genet. 2010 Nov;121(8):1541-52. doi: 10.1007/s00122-010-1409-3. Epub 2010 Jul 24.
Fluorescent in situ hybridization (FISH) with multiple probes was used to analyze mitotic and meiotic chromosome spreads of Avena sativa cv 'Sun II' monosomic lines, and of A. byzantina cv 'Kanota' monosomic lines from spontaneous haploids. The probes used were A. strigosa pAs120a (a repetitive sequence abundant in A-genome chromatin), A. murphyi pAm1 (a repetitive sequence abundant in C-genome chromatin), A. strigosa pITS (internal transcribed spacer of rDNA) and the wheat rDNA probes pTa71 (nucleolus organizer region or NOR) and pTa794 (5S). Simultaneous and sequential FISH employing pairs of these probes allowed the identification and genome assignation of all chromosomes. FISH mapping using mitotic and meiotic metaphases facilitated the genomic and chromosomal identification of the monosome in each line. Of the 17 'Sun II' lines analyzed, 13 distinct monosomic lines were found, corresponding to four monosomes of the A-genome, five of the C-genome and four of the D-genome. In addition, 12 distinct monosomic lines were detected among the 20 'Kanota' lines examined, corresponding to six monosomes of the A-genome, three of the C-genome and three of the D-genome. The results show that 19 chromosomes out of 21 of the complement are represented by monosomes between the two genetic backgrounds. The identity of the remaining chromosomes can be deduced either from one intergenomic translocation detected on both 'Sun II' and 'Kanota' lines, or from the single reciprocal, intergenomic translocation detected among the 'Sun II' lines. These results permit a new system to be proposed for numbering the 21 chromosome pairs of the hexaploid oat complement. Accordingly, the A-genome contains chromosomes 8A, 11A, 13A, 15A, 16A, 17A and 19A; the C-genome contains chromosomes 1C, 2C, 3C, 4C, 5C, 6C and 7C; and the D-genome consists of chromosomes 9D, 10D, 12D, 14D, 18D, 20D and 21D. Moreover, the FISH patterns of 16 chromosomes in 'Sun II' and 15 in 'Kanota' suggest that these chromosomes could be involved in intergenomic translocations. By comparing the identities of individually translocated chromosomes in the two hexaploid species with those of other hexaploids, we detected different types of intergenomic translocations.
荧光原位杂交（FISH）技术结合多种探针被用于分析燕麦品种‘Sun II’的单体和自发单倍体的 A. byzantina cv 'Kanota'的有丝分裂和减数分裂染色体铺片。使用的探针包括 A. strigosa pAs120a（富含 A 基因组染色质的重复序列）、A. murphyi pAm1（富含 C 基因组染色质的重复序列）、A. strigosa pITS（rDNA 内部转录间隔区）和小麦 rDNA 探针 pTa71（核仁组织区或 NOR）和 pTa794（5S）。这些探针的同时和顺序 FISH 可以识别和基因组分配所有染色体。利用有丝分裂和减数分裂中期染色体的 FISH 作图有助于确定每条单体的基因组和染色体身份。在分析的 17 个‘Sun II’品系中，发现了 13 个独特的单体，对应于 A 基因组的 4 个单体、C 基因组的 5 个单体和 D 基因组的 4 个单体。此外，在 20 个‘Kanota’品系中检测到 12 个独特的单体，对应于 A 基因组的 6 个单体、C 基因组的 3 个单体和 D 基因组的 3 个单体。结果表明，在这两个遗传背景下，21 个染色体对中的 19 个染色体由单体代表。其余染色体的身份可以通过在‘Sun II’和‘Kanota’品系中检测到的一个种间易位或在‘Sun II’品系中检测到的一个相互易位来推断。这些结果提出了一个新的系统来对六倍体燕麦的 21 对染色体进行编号。因此，A 基因组包含染色体 8A、11A、13A、15A、16A、17A 和 19A；C 基因组包含染色体 1C、2C、3C、4C、5C、6C 和 7C；D 基因组由染色体 9D、10D、12D、14D、18D、20D 和 21D 组成。此外，在‘Sun II’中的 16 条染色体和‘Kanota’中的 15 条染色体的 FISH 模式表明，这些染色体可能涉及种间易位。通过比较两个六倍体物种中单独易位染色体的身份与其他六倍体物种的身份，我们检测到了不同类型的种间易位。
