B73-Mo17 Near-Isogenic Lines Demonstrate Dispersed Structural Variation in Maize

Department of Plant Biology, University of Minnesota, Saint Paul, Minnesota 55108, USA.
Plant physiology (Impact Factor: 6.84). 06/2011; 156(4):1679-90. DOI: 10.1104/pp.111.174748
Source: PubMed


Recombinant inbred lines developed from the maize (Zea mays ssp. mays) inbreds B73 and Mo17 have been widely used to discover quantitative trait loci controlling a wide variety of phenotypic traits and as a resource to produce high-resolution genetic maps. These two parents were used to produce a set of near-isogenic lines (NILs) with small regions of introgression into both backgrounds. A novel array-based genotyping platform was used to score genotypes of over 7,000 loci in 100 NILs with B73 as the recurrent parent and 50 NILs with Mo17 as the recurrent parent. This population contains introgressions that cover the majority of the maize genome. The set of NILs displayed an excess of residual heterozygosity relative to the amount expected based on their pedigrees, and this excess residual heterozygosity is enriched in the low-recombination regions near the centromeres. The genotyping platform provided the ability to survey copy number variants that exist in more copies in Mo17 than in B73. The majority of these Mo17-specific duplications are located in unlinked positions throughout the genome. The utility of this population for the discovery and validation of quantitative trait loci was assessed through analysis of plant height variation.

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Available from: Cheng-Ting Yeh, Jan 29, 2015
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    • "Genetic mapping has identified quantitative trait loci (QTL) that confer resistance to several maize-feeding insects, including Diatraea grandiosella (southwestern corn borer; Khairallah et al., 1998), Ostrinia nubilalis (European corn borer; Papst et al., 2004), Ostrinia furnacalis (Asian corn borer; Xia et al., 2010), Helicoverpa zea (corn earworm; Byrne et al., 1998), Spodoptera frugiperda (fall armyworm; Brooks et al., 2007), and Sitophilus zeamais (maize weevil, García-Lara et al., 2009). Discovery of the actual genetic basis of such insect resistance QTL has been facilitated by the genome sequence of maize inbred line B73 (Schnable et al., 2009), as well as by populations of recombinant inbred lines (RILs) and nearisogenic lines (NILs) that have been created from B73 and a diverse set of other maize inbred lines (Eichten et al., 2011; Lee et al., 2002; McMullen et al., 2009b; Yu et al., 2008). The proximal causes of natural variation in maize insect resistance have been linked to the production of defensive proteins and secondary metabolites. "
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