Genomic characterization of DArT markers based on high-density linkage analysis and physical mapping to the Eucalyptus genome

PLoS One. 2012;7(9):e44684. doi: 10.1371/journal.pone.0044684. Epub 2012 Sep 11.

Abstract

Diversity Arrays Technology (DArT) provides a robust, high throughput, cost-effective method to query thousands of sequence polymorphisms in a single assay. Despite the extensive use of this genotyping platform for numerous plant species, little is known regarding the sequence attributes and genome-wide distribution of DArT markers. We investigated the genomic properties of the 7,680 DArT marker probes of a Eucalyptus array, by sequencing them, constructing a high density linkage map and carrying out detailed physical mapping analyses to the Eucalyptus grandis reference genome. A consensus linkage map with 2,274 DArT markers anchored to 210 microsatellites and a framework map, with improved support for ordering, displayed extensive collinearity with the genome sequence. Only 1.4 Mbp of the 75 Mbp of still unplaced scaffold sequence was captured by 45 linkage mapped but physically unaligned markers to the 11 main Eucalyptus pseudochromosomes, providing compelling evidence for the quality and completeness of the current Eucalyptus genome assembly. A highly significant correspondence was found between the locations of DArT markers and predicted gene models, while most of the 89 DArT probes unaligned to the genome correspond to sequences likely absent in E. grandis, consistent with the pan-genomic feature of this multi-Eucalyptus species DArT array. These comprehensive linkage-to-physical mapping analyses provide novel data regarding the genomic attributes of DArT markers in plant genomes in general and for Eucalyptus in particular. DArT markers preferentially target the gene space and display a largely homogeneous distribution across the genome, thereby providing superb coverage for mapping and genome-wide applications in breeding and diversity studies. Data reported on these ubiquitous properties of DArT markers will be particularly valuable to researchers working on less-studied crop species who already count on DArT genotyping arrays but for which no reference genome is yet available to allow such detailed characterization.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromosome Mapping / methods*
  • Chromosomes, Plant
  • Cost-Benefit Analysis
  • DNA, Plant / genetics
  • Eucalyptus / genetics*
  • Genetic Linkage
  • Genetic Markers*
  • Genome, Plant
  • Genomics
  • Genotype
  • Microsatellite Repeats / genetics
  • Models, Genetic
  • Oligonucleotide Array Sequence Analysis / methods*
  • Sequence Analysis, DNA / methods

Substances

  • DNA, Plant
  • Genetic Markers

Grants and funding

The project was supported by the Brazilian Ministry of Science and Technology (CNPq Project Grants 559245/2008-4 and 560831/2008-0) and PRONEX FAP-DF Project Grant "NEXTREE" 193.000.570/2009 to DG. This study was carried out as part of Cesar Petroli's doctoral thesis at the University of Brasilia. CPS and CDP had doctoral fellowships from CAPES (Brazilian Ministry of Education) and DG a productivity research fellowship from CNPq. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.