title: Remnants of the Legume Ancestral Genome Preserved in Gene-Rich Regions: Insights fromLupinus angustifoliusPhysical, Genetic, and Comparative Mapping.
abstract: The narrow-leafed lupin (Lupinus angustifolius) was recently considered as a legume reference species. Genetic resources have been developed, including a draft genome sequence, linkage maps, nuclear DNA libraries, and cytogenetic chromosome-specific landmarks. Here, we used a complex approach, involving DNA fingerprinting, sequencing, genetic mapping, and molecular cytogenetics, to localize and analyzeL. angustifoliusgene-rich regions (GRRs). AL. angustifoliusgenomic bacterial artificial chromosome (BAC) library was screened with short sequence repeat (SSR)-based probes. Selected BACs were fingerprinted and assembled into contigs. BAC-end sequence (BES) annotation allowed us to choose clones for sequencing, targeting GRRs. Additionally, BESs were aligned to the scaffolds of the genome sequence. The genetic map was supplemented with 35 BES-derived markers, distributed in 14 linkage groups and tagging 37 scaffolds. The identified GRRs had an average gene density of 19.6 genes/100 kb and physical-to-genetic distance ratios of 11 to 109 kb/cM. Physical and genetic mapping was supported by multi-BAC-fluorescence in situ hybridization (FISH), and five new linkage groups were assigned to the chromosomes. Syntenic links to the genome sequences of five legume species (Medicago truncatula,Glycine max,Lotus japonicus,Phaseolus vulgaris, andCajanus cajan) were identified. The comparative mapping of the two largest lupin GRRs provides novel evidence for ancient duplications in all of the studied species. These regions are conserved among representatives of the main clades of Papilionoideae. Furthermore, despite the complex evolution of legumes, some segments of the nuclear genome were not substantially modified and retained their quasi-ancestral structures. Cytogenetic markers anchored in these regions constitute a platform for heterologous mapping of legume genomes.
authors.affiliation: Department of Genomics, Institute of Plant Genetics of the Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznan, Poland.
authors.forename: Michał
authors.initials: M
authors.lastname: Książkiewicz
authors.affiliation: Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Zielezinski
authors.affiliation: Department of Genomics, Institute of Plant Genetics of the Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznan, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Wyrwa
authors.affiliation: Department of Genomics, Institute of Plant Genetics of the Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznan, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Szczepaniak
authors.affiliation: Department of Genomics, Institute of Plant Genetics of the Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznan, Poland.
authors.forename: Sandra
authors.initials: S
authors.lastname: Rychel
authors.affiliation: Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland.
authors.forename: Wojciech
authors.initials: W
authors.lastname: Karlowski
authors.affiliation: Department of Genomics, Institute of Plant Genetics of the Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznan, Poland.
authors.forename: Bogdan
authors.initials: B
authors.lastname: Wolko
authors.affiliation: Department of Genomics, Institute of Plant Genetics of the Polish Academy of Sciences, Strzeszyńska 34, 60-479 Poznan, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Naganowska
keywords: BAC-FISH; Genome; Molecular marker; Narrow-leafed lupin; Sequencing; Synteny