Paternal Dominance of Trans-eQTL Influences Gene Expression Patterns in Maize Hybrids

• Published in: Science (American Association for the Advancement of Science) Vol. 326; no. 5956; pp. 1118 - 1120
• Main Authors: Swanson-Wagner, Ruth A, DeCook, Rhonda, Jia, Yi, Bancroft, Tim, Ji, Tieming, Zhao, Xuefeng, Nettleton, Dan, Schnable, Patrick S
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 20.11.2009; The American Association for the Advancement of Science
• Subjects: Agronomy. Soil science and plant productions; alleles; Biological and medical sciences; Chromosome Mapping; Corn; Crosses, Genetic; Dominance; Fundamental and applied biological sciences. Psychology; Gene expression; Gene Expression Profiling; Gene expression regulation; Gene Expression Regulation, Plant; Gene mapping; Genes; Genes, Plant; Genetic markers; Genetics and breeding of economic plants; Genome, Plant; Genomes; Genomic Imprinting; Genotypes; Geometric lines; Heterosis; Heterosis. Floral biology applications: apomixy, male sterility, incompatibility, varia; Hybrid Vigor; Hybridity; Hybridization; Hybridization, Genetic; Hybrids; Inbreeding; Oligonucleotide Array Sequence Analysis; parents; Phenotype; Plant breeding: fundamental aspects and methodology; progeny; Quantitative Trait Loci; Zea mays; Zea mays - genetics; Zea mays - physiology; Hybrid variety; Monocotyledones; Zea mays; Gramineae; Angiospermae; Dominance; Spermatophyta; Genetic determinism; Cereal crop
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.1178294

Heterosis refers to the superior performance of hybrid progeny relative to their inbred parents, but the mechanisms responsible are unknown. Hybrids between the maize inbred lines B73 and Mo17 exhibit heterosis regardless of cross direction. These reciprocal hybrids differ from each other phenotypically, and 30 to 50% of their genes are differentially expressed. We identified approximately 4000 expression quantitative trait loci (eQTL) that allowed us to identify markers linked to variation in expression. We found that over three-quarters of these eQTL act in trans (78%) and that 86% of these differentially regulate transcript accumulation in a manner consistent with gene expression in the hybrid being regulated exclusively by the paternally transmitted allele. This result suggests that widespread imprinting contributes to the regulation of gene expression in maize hybrids.