Interval mapping of viability loci causing heterosis in Arabidopsis.
The genetic basis of heterosis has implications for many problems in genetics and evolution. Heterosis and inbreeding depression affect human genetic diseases, maintenance of genetic variation, evolution of breeding systems, agricultural productivity, and conservation biology. Despite decades of theoretical and empirical studies, the genetic basis of heterosis has remained unclear. I mapped viability loci contributing to heterosis in Arabidopsis. An overdominant factor with large effects on viability mapped to a short interval on chromosome I. Homozygotes had 50% lower viability than heterozygotes in this chromosomal region. Statistical analysis of viability data in this cross indicates that observed viability heterosis is better explained by functional overdominance than by pseudo-overdominance. Overdominance sometimes may be an important cause of hybrid vigor, especially in habitually inbreeding species. Finally, I developed a maximum likelihood interval mapping procedure that can be used to examine chromosomal regions showing segregation distortion or viability selection.
Duke Scholars
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Related Subject Headings
- Probability
- Models, Genetic
- Hybrid Vigor
- Humans
- Heterozygote
- Genotype
- Genetic Diseases, Inborn
- Developmental Biology
- Chromosome Mapping
- Biological Evolution
Citation
Published In
DOI
EISSN
ISSN
Publication Date
Volume
Issue
Start / End Page
Related Subject Headings
- Probability
- Models, Genetic
- Hybrid Vigor
- Humans
- Heterozygote
- Genotype
- Genetic Diseases, Inborn
- Developmental Biology
- Chromosome Mapping
- Biological Evolution