Physical mapping of bread wheat chromosome 5A: an integrated approach

ABSTRACT: The huge size, the redundancy and the great repeated portion of the bread wheat genome [Triticum aestivum (L.)], placed it among the most difficult species to be sequenced and dissected at the genetic, structural and evolutionary levels. To overcome the limitations, a strategy based on the genome compartmentalization in individual chromosomes and the subsequent production of physical maps was established within the frame of the International Wheat Genome Sequence Consortium. A total of 95,812 BAC clones of short (5AS) and long (5AL) arm-specific BAC libraries, were fingerprinted and assembled into contigs by complementary analytical approaches based on FingerPrinted Contigs and Linear Topological Contig. Combined anchoring approaches based on PCR marker screening, microarray and BlastN searches, applied to interlinked genomic tools, that is genetic maps, deletion bin map, high-density neighbor map, BAC end sequences, genome zipper and chromosome survey sequences, allowed the development of a high quality physical map, with an anchored physical coverage of 75% for 5AS and 53% for 5AL, with high portions (64 and 48%, respectively) ordered along the chromosome. The gene distribution along the wheat chromosome 5A compared with the closest related genomes showed a pattern of syntenic blocks belonging to different chromosomes of Brachypodium, rice and sorghum and regions involving translocations and inversions. The physical map presented here is currently the most comprehensive map for 5A chromosome and represents an essential resource for fine genetic mapping and map-based cloning of agronomically relevant traits, and a reference for the 5A sequencing projects. 55 DNA pools of short arm of chromsome 5A and 63 DNA pools of long arm of 5A. The DNAs derive from BAC clones of the Minimal Tiling Paths produced by physical assemly of BAC fingerprints.

ORGANISM(S): Triticum aestivum

SUBMITTER: Delfina Barabaschi 

PROVIDER: E-GEOD-66996 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress