Cytogenetic mapping with centromeric bacterial artificial chromosomes contigs shows that this recombination-poor region comprises more than half of barley chromosome 3H
Cytogenetic mapping with centromeric bacterial artificial chromosomes contigs shows that this recombination-poor region comprises more than half of barley chromosome 3H
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DOI：
10.1111/tpj.13006
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发表时间：
2015-10-01
期刊：
影响因子：
7.2
通讯作者：
Houben, Andreas
中科院分区：
文献类型：
--
作者：
Aliyeva-Schnorr, Lala;Beier, Sebastian;Houben, Andreas
遗传图谱以重组的频率为基础，与物理图谱相比，通常显示分子标记的不同位置，特别是在减数分裂重组通常较差的着丝粒中。为了确定大麦（Hordeum vulgare） 3H染色体着丝粒DNA序列的位置和顺序，利用65个细菌人工染色体（BAC）指纹图谱的70个基因组单拷贝探针，对有丝分裂中期和减数分裂粗线染色体进行了荧光原位杂交。3H的着丝粒5.5cM染色体的总物理分布占有丝分裂中期染色体长度的58%。有丝分裂和减数分裂染色质的重组缺失区域优先被异染色质典型组蛋白标记（H3K9me2）标记，而重组富集的亚末端染色体区域则被常染色质典型组蛋白标记（H3K4me2, H3K4me3, H3K27me3）标记，这表明减数分裂重组率可能受到染色质景观的影响。为了充分利用大麦基因组进行作物改良，有必要更好地了解物理距离和遗传距离之间的关系。在这里，我们使用荧光原位杂交的低拷贝探针来排序与大麦的非重组遗传着丝粒相对应的contigs。
Genetic maps are based on the frequency of recombination and often show different positions of molecular markers in comparison to physical maps, particularly in the centromere that is generally poor in meiotic recombinations. To decipher the position and order of DNA sequences genetically mapped to the centromere of barley (Hordeum vulgare) chromosome 3H, fluorescence in situ hybridization with mitotic metaphase and meiotic pachytene chromosomes was performed with 70 genomic single-copy probes derived from 65 fingerprinted bacterial artificial chromosomes (BAC) contigs genetically assigned to this recombination cold spot. The total physical distribution of the centromeric 5.5cM bin of 3H comprises 58% of the mitotic metaphase chromosome length. Mitotic and meiotic chromatin of this recombination-poor region is preferentially marked by a heterochromatin-typical histone mark (H3K9me2), while recombination enriched subterminal chromosome regions are enriched in euchromatin-typical histone marks (H3K4me2, H3K4me3, H3K27me3) suggesting that the meiotic recombination rate could be influenced by the chromatin landscape.Significance Statement To fully exploit the barley genome for crop improvement, it is necessary to better understand the relationship between physical and genetic distances. Here we used low-copy probes for fluorescence in situ hybridization to order contigs corresponding to a non-recombining genetic centromere of barley.