Candice Gardner

Height is one of the most heritable and easily measured traits in maize (Zea mays L.). Given a pedigree or estimates of the genomic identity-by-state among related plants, height is also accurately predictable. But, mapping alleles explaining natural variation in maize height remains a formidable challenge. To address this challenge, we measured the plant height, ear height, flowering time, and node counts of plants grown in >64,500 plots across 13 environments. These plots contained >7300 inbreds representing most publically available maize inbreds in the United States and families of the maize Nested Association Mapping (NAM) panel. Joint-linkage mapping of quantitative trait loci (QTL), fine mapping in near isogenic lines (NILs), genome-wide association studies (GWAS), and genomic best linear unbiased prediction (GBLUP) were performed. The heritability of maize height was estimated to be >90%. Mapping NAM family-nested QTL revealed the largest explained 2.1 ± 0.9% of hei...

BackgroundResistance to Fusarium ear rot of maize is a quantitative and complex trait. Marker-trait associations to date have had small additive effects and were inconsistent between previous studies, likely due to the combined effects of genetic heterogeneity and low power of detection of many small effect variants. The complexity of inheritance of resistance hinders the use marker-assisted selection for ear rot resistance.ResultsWe conducted a genome-wide association study (GWAS) for Fusarium ear rot resistance in a panel of 1687 diverse inbred lines from the USDA maize gene bank with 200,978 SNPs while controlling for background genetic relationships with a mixed model and identified seven single nucleotide polymorphisms (SNPs) in six genes associated with disease resistance in either the complete inbred panel (1687 lines with highly unbalanced phenotype data) or in a filtered inbred panel (734 lines with balanced phenotype data). Different sets of SNPs were detected as associate...

Page 1. Sathaporn Srichuwong, 1 Jelena Gutesa, 1 Michael Blanco, 2 Susan A. Duvick, 2 Candice Gardner, 2 and Jay-Lin Jane 3 ... Sample Code Inventory Pedigree GEM Code Country Race A 05GEM06031 DKB844:S1601-073-001-BBBBB GEMS-0115 Mexico Tropical hybrid ...

The genotypes and biological phenotypes of HIV-1 isolates obtained from 40 perinatally infected children in South Africa were analyzed. This included 15 infants who had HIV-related symptoms, most of whom died within 2 years of birth (rapid progressors), and 25 children who survived between 4 and 9 years with varying signs of disease (slow progressors). Heteroduplex mobility assays and sequence analysis confirmed that within the env and gag regions, all isolates were HIV-1 subtype C. Viral isolates from 14 of the 15 rapid progressors used the CCR5 coreceptor, whereas 1 (02ZARP1) used both the CXCR4 and CCR5 coreceptors. Among the 25 slow progressors, 22 isolates used CCR5 only, 2 used CXCR4 only, and 1 used both CCR5 and CXCR4. Two of the slow-progressing children who harbored CXCR4-using viruses had AIDS. All four CXCR4-using viruses had genotypic changes in the V3 region previously shown to be associated with CXCR4 usage. This cross-sectional study shows that HIV-1 subtype C viruse...

BackgroundPlants rely on the root system for anchorage to the ground, as well the acquisition and absorption of nutrients critical to sustaining productivity. Genome wide association analysis enables to analyze allelic diversity of complex traits and identify superior alleles. 384 inbred lines from the Ames panel were genotyped with 681,257 single nucleotide polymorphism markers using Genotyping-by-Sequencing technology and 22 seedling root architecture traits were phenotyped.ResultsUtilizing both a general linear model and mixed linear model genome wide association study to account for population structure, 268 marker trait associations (p¿¿¿5.3x10-7) were identified. Analysis of significant SNP markers for multiple traits showed that several were located within gene models with some SNP markers localized within regions with previously identified root quantitative trait loci. Gene model GRMZM2G153722 located on chromosome 4 contained nine significant markers. This predicted gene is...