Submitted to: Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 18, 2008
Publication Date: January 5, 2009
Citation: Coates, B.S., Sumerford, D.V., Hellmich II, R.L., Lewis, L.C. 2009. Repetitive Genomic Elements in a European Corn Borer, Ostrinia nubilalis, Bacterial Artificial Chromosome Library were Indicated by Bacterial Artificial Chromosome End Sequencing and Development of Sequence Tag Site Markers: Implications for Lepidopteran Genomic Research. Genome. 52(1):57-67. Interpretive Summary: Genetically-engineered (transgenic) crop plants have been produced to kill insects that feed upon them. Scientists and crop producers see benefits in these plants because they offer an effective way to kill pests without harmful environmental effects of conventional chemical insecticides. Reduced chemical usage translates into less surface and ground water contamination. European corn borer, an important pest of corn in the United States, is controlled by transgenic Bt (Bacillus thuringiensis) corn. Damage and control costs for this insect exceed $1 billion from an annual crop valued at more than $22 billion. Nearly complete control of European corn borer on Bt transgenic corn, however, has many scientists concerned that this pest could become resistant to these plants. In this study, a bacterial artificial chromosome (BAC) library was constructed of the European corn borer, and methods described for isolation of genes of interest including candidate Bt resistance genes. This research provides a molecular tool for characterization of the possible resistance genes. The genetics of insect resistance will be useful for all stakeholders interested in finding novel ways to control European corn borers and sustain Bt technology.
Technical Abstract: The European corn borer, Ostrinia nubilalis, is a serious pest of food, fiber, and biofuel crops in Europe, North America, and Asia, and a model system for insect olfaction and speciation. A bacterial artificial chromosome (BAC) library constructed for O. nubilalis contains 36,864 clones with estimated average insert size greater than or equal to 120 kb and genome coverage of 8.8 fold. Screening OnB1 clones comprising approximately 2.76-fold genome equivalents determined physical position of 24 sequence tag site (STS) markers, including markers linked to ecologically-important traits and identified as candidate Bacillus thuringiensis toxin resistance genes. OnB1 BAC end sequence (BES) reads [GenBank dbGSS (Genomic Survey Sequence) accessions ET217010 to ET217273] showed homology to annotated genes or ESTs (expressed sequence tag), and identified repetitive genome elements, O. nubilalis miniature subterminal inverted repeat transposable elements (OnMSITE01 and 02), and ezi-like long interspersed nuclear elements (LINEs). Mobility of OnMSITE01 was demonstrated by presence or absence in O. nubilalis introns at two different loci. A (GTCT)n tetranucleotide repeat at 5 prime ends OnMSITE01 and 02 are evidence for transposon-mediated movement of lepidopteran microsatellite loci. The number of repetitive elements in lepidopteran genomes will affect genome assembly and marker development. Single locus STS markers described here has downstream application for integration within linkage maps and comparative genomic studies.