KEY MESSAGE: Making use of wheat chromosomal resources, we developed 11 gene-associated markers for the region of interest, which allowed reducing gene interval and spanning it by four BAC clones. Positional gene cloning and targeted marker development in bread wheat are hampered by high complexity and polyploidy of its nuclear genome. Aiming to clone a Russian wheat aphid resistance gene Dn2401 located on wheat chromosome arm 7DS, we have developed a strategy overcoming problems due to polyploidy and enabling efficient development of gene-associated markers from the region of interest. We employed information gathered by GenomeZipper, a synteny-based tool combining sequence data of rice, Brachypodium, sorghum and barley, and took advantage of a high-density linkage map of Aegilops tauschii. To ensure genome- and locus-specificity of markers, we made use of survey sequence assemblies of isolated wheat chromosomes 7A, 7B and 7D. Despite the low level of polymorphism of the wheat D subgenome, our approach allowed us to add in an efficient and cost-effective manner 11 new gene-associated markers in the Dn2401 region and narrow down the target interval to 0.83 cM. Screening 7DS-specific BAC library with the flanking markers revealed a contig of four BAC clones that span the Dn2401 region in wheat cultivar 'Chinese Spring'. With the availability of sequence assemblies and GenomeZippers for each of the wheat chromosome arms, the proposed strategy can be applied for focused marker development in any region of the wheat genome.

• MeSH
• býložravci MeSH
• chromozomy rostlin MeSH
• DNA primery MeSH
• DNA rostlinná genetika   MeSH
• genetická vazba MeSH
• genetické markery MeSH
• genomika MeSH
• jednonukleotidový polymorfismus MeSH
• mapování chromozomů * MeSH
• mikrosatelitní repetice MeSH
• mšice * MeSH
• pšenice genetika   MeSH
• rostlinné geny * MeSH
• syntenie MeSH
• umělé bakteriální chromozomy MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Rusko MeSH

Positional cloning in bread wheat is a tedious task due to its huge genome size and hexaploid character. BAC libraries represent an essential tool for positional cloning. However, wheat BAC libraries comprise more than million clones, which makes their screening very laborious. Here, we present a targeted approach based on chromosome-specific BAC libraries. Such libraries were constructed from flow-sorted arms of wheat chromosome 7D. A library from the short arm (7DS) consisting of 49,152 clones with 113 kb insert size represented 12.1 arm equivalents whereas a library from the long arm (7DL) comprised 50,304 clones of 116 kb providing 14.9x arm coverage. The 7DS library was PCR screened with markers linked to Russian wheat aphid resistance gene DnCI2401, the 7DL library was screened by hybridization with a probe linked to greenbug resistance gene Gb3. The small number of clones combined with high coverage made the screening highly efficient and cost effective.

• MeSH
• chromozomy rostlin genetika   MeSH
• fluorescence MeSH
• hybridizace nukleových kyselin genetika   MeSH
• karyotypizace MeSH
• klonování DNA metody   MeSH
• mikrosatelitní repetice genetika   MeSH
• mšice fyziologie   MeSH
• nemoci rostlin genetika   imunologie   parazitologie   MeSH
• polymerázová řetězová reakce MeSH
• přirozená imunita genetika   MeSH
• pšenice genetika   imunologie   parazitologie   MeSH
• rostlinné geny genetika   MeSH
• umělé bakteriální chromozomy genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH