title: Characterization of a deep-coverage carrot (Daucus carota L.) BAC library and initial analysis of BAC-end sequences.
abstract: Carrot is the most economically important member of the Apiaceae family and a major source of provitamin A carotenoids in the human diet. However, carrot molecular resources are relatively underdeveloped, hampering a number of genetic studies. Here, we report on the synthesis and characterization of a bacterial artificial chromosome (BAC) library of carrot. The library is 17.3-fold redundant and consists of 92,160 clones with an average insert size of 121 kb. To provide an overview of the composition and organization of the carrot nuclear genome we generated and analyzed 2,696 BAC-end sequences (BES) from nearly 2,000 BACs, totaling 1.74 Mb of BES. This analysis revealed that 14% of the BES consists of known repetitive elements, with transposable elements representing more than 80% of this fraction. Eleven novel carrot repetitive elements were identified, covering 8.5% of the BES. Analysis of microsatellites showed a comparably low frequency for these elements in the carrot BES. Comparisons of the translated BES with protein databases indicated that approximately 10% of the carrot genome represents coding sequences. Moreover, among eight dicot species used for comparison purposes, carrot BES had highest homology to protein-coding sequences from tomato. This deep-coverage library will aid carrot breeding and genetics.
authors.affiliation: Department of Horticulture, University of Wisconsin, 1575 Linden Drive, Madison, WI 53706, USA.
authors.forename: Pablo F
authors.initials: PF
authors.lastname: Cavagnaro
authors.forename: Sang-Min
authors.initials: SM
authors.lastname: Chung
authors.forename: Marek
authors.initials: M
authors.lastname: Szklarczyk
authors.forename: Dariusz
authors.initials: D
authors.lastname: Grzebelus
authors.forename: Douglas
authors.initials: D
authors.lastname: Senalik
authors.forename: Anne E
authors.initials: AE
authors.lastname: Atkins
authors.forename: Philipp W
authors.initials: PW
authors.lastname: Simon
mesh_terms: D001483:Base Sequence; D022202:Chromosomes, Artificial, Bacterial / Q000235:genetics*; D017931:DNA Primers / Q000235:genetics; D018744:DNA, Plant / Q000235:genetics; D030561:Databases, Nucleic Acid; D018552:Daucus carota / Q000235:genetics*; D020224:Expressed Sequence Tags; D015723:Gene Library; D018598:Minisatellite Repeats; D013045:Species Specificity
chemical_list: D017931:DNA Primers; D018744:DNA, Plant