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Paternally expressed imprinted genes under positive Darwinian selection in Arabidopsis thaliana
- Source :
- Molecular Biology and Evolution
- Publication Year :
- 2019
- Publisher :
- Oxford University Press (OUP), 2019.
-
Abstract
- Genomic imprinting is an epigenetic phenomenon where autosomal genes display uniparental expression depending on whether they are maternally or paternally inherited. Genomic imprinting can arise from parental conflicts over resource allocation to the offspring, which could drive imprinted loci to evolve by positive selection. We investigate whether positive selection is associated with genomic imprinting in the inbreeding species Arabidopsis thaliana. Our analysis of 140 genes regulated by genomic imprinting in the A. thaliana seed endosperm demonstrates they are evolving more rapidly than expected. To investigate whether positive selection drives this evolutionary acceleration, we identified orthologs of each imprinted gene across 34 plant species and elucidated their evolutionary trajectories. Increased positive selection was sought by comparing its incidence among imprinted genes with nonimprinted controls. Strikingly, we find a statistically significant enrichment of imprinted paternally expressed genes (iPEGs) evolving under positive selection, 50.6% of the total, but no such enrichment for positive selection among imprinted maternally expressed genes (iMEGs). This suggests that maternally- and paternally expressed imprinted genes are subject to different selective pressures. Almost all positively selected amino acids were fixed across 80 sequenced A. thaliana accessions, suggestive of selective sweeps in the A. thaliana lineage. The imprinted genes under positive selection are involved in processes important for seed development including auxin biosynthesis and epigenetic regulation. Our findings support a genomic imprinting model for plants where positive selection can affect paternally expressed genes due to continued conflict with maternal sporophyte tissues, even when parental conflict is reduced in predominantly inbreeding species.
- Subjects :
- 0106 biological sciences
Lineage (genetic)
Genomic imprinting
Arabidopsis
Positive Darwinian selection
Biology
010603 evolutionary biology
01 natural sciences
Evolution, Molecular
03 medical and health sciences
Plant evolution
Genetics
Arabidopsis thaliana
Genomic conflict
Epigenetics
Selection, Genetic
Molecular Biology
Gene
Discoveries
Ecology, Evolution, Behavior and Systematics
Selection (genetic algorithm)
030304 developmental biology
0303 health sciences
Arabidopsis Proteins
food and beverages
DNA-Directed RNA Polymerases
15. Life on land
biology.organism_classification
Endosperm
Inbreeding
Subjects
Details
- Language :
- English
- ISSN :
- 07374038 and 15371719
- Database :
- OpenAIRE
- Journal :
- Molecular Biology and Evolution
- Accession number :
- edsair.doi.dedup.....508075fea592e421f24fd44b3f70c18f